Search results for: low speed flexi wing
3079 Aerodynamic Investigation of Baseline-IV Bird-Inspired BWB Aircraft Design: Improvements over Baseline-III BWB
Authors: C. M. Nur Syazwani, M. K. Ahmad Imran, Rizal E. M. Nasir
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The study on BWB UV begins in UiTM since 2005 and three designs have been studied and published. The latest designs are Baseline-III and inspired by birds that have features and aerodynamics behaviour of cruising birds without flapping capability. The aircraft featuring planform and configuration are similar to the bird. Baseline-III has major flaws particularly in its low lift-to-drag ratio, stability and issues regarding limited controllability. New design known as Baseline-IV replaces straight, swept wing to delta wing and have a broader tail compares to the Baseline-III’s. The objective of the study is to investigate aerodynamics of Baseline-IV bird-inspired BWB aircraft. This will be achieved by theoretical calculation and wind tunnel experiments. The result shows that both theoretical and wind tunnel experiments of Baseline-IV graph of CL and CD versus alpha are quite similar to each other in term of pattern of graph slopes and values. Baseline-IV has higher lift coefficient values at wide range of angle of attack compares to Baseline-III. Baseline-IV also has higher maximum lift coefficient, higher maximum lift-to-drag and lower parasite drag. It has stable pitch moment versus lift slope but negative moment at zero lift for zero angle-of-attack tail setting. At high angle of attack, Baseline-IV does not have stability reversal as shown in Baseline-III. Baseline-IV is proven to have improvements over Baseline-III in terms of lift, lift-to-drag ratio and pitch moment stability at high angle-of-attack.Keywords: blended wing-body, bird-inspired blended wing-body, aerodynamic, stability
Procedia PDF Downloads 5083078 Ergonomic Design of Speed Control Humps/Dips
Authors: Emad Khorshid, Habib Awada
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Newly developed Ergonomic speed control hump/Dip designs are conducted. The numerical simulation for the driver-vehicle-hump dynamic system will be performed using computer software. The design problem for which the speed hump or dip should provide: (1) discomfort feeling to the driver if speed is over the specified limit, and (2) normal/good comfort level to the driver (and or other passengers) if the speed is within the limit. For comparison reasons, different vehicles suspension systems (active, semi-active and non-active suspension) are used in the simulation. The measuring of the acceptable range of vibration will be referenced to the British standard BS6841, ISO 2631/1 and the new ISO 2631/5. All these standards are related to human health and comfort level in terms of acceptable range of whole body vibration exposure.Keywords: speed hump, speed dip, ergonomic design, human health, vehicle modeling
Procedia PDF Downloads 3713077 Analyzing of Speed Disparity in Mixed Vehicle Technologies on Horizontal Curves
Authors: Tahmina Sultana, Yasser Hassan
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Vehicle technologies rapidly evolving due to their multifaceted advantages. Adapted different vehicle technologies like connectivity and automation on the same roads with conventional vehicles controlled by human drivers may increase speed disparity in mixed vehicle technologies. Identifying relationships between speed distribution measures of different vehicles and road geometry can be an indicator of speed disparity in mixed technologies. Previous studies proved that speed disparity measures and traffic accidents are inextricably related. Horizontal curves from three geographic areas were selected based on relevant criteria, and speed data were collected at the midpoint of the preceding tangent and starting, ending, and middle point of the curve. Multiple linear mixed effect models (LME) were developed using the instantaneous speed measures representing the speed of vehicles at different points of horizontal curves to recognize relationships between speed variance (standard deviation) and road geometry. A simulation-based framework (Monte Carlo) was introduced to check the speed disparity on horizontal curves in mixed vehicle technologies when consideration is given to the interactions among connected vehicles (CVs), autonomous vehicles (AVs), and non-connected vehicles (NCVs) on horizontal curves. The Monte Carlo method was used in the simulation to randomly sample values for the various parameters from their respective distributions. Theresults show that NCVs had higher speed variation than CVs and AVs. In addition, AVs and CVs contributed to reduce speed disparity in the mixed vehicle technologies in any penetration rates.Keywords: autonomous vehicles, connected vehicles, non-connected vehicles, speed variance
Procedia PDF Downloads 1453076 The Shrinking of the Pink Wave and the Rise of the Right-Wing in Latin America
Authors: B. M. Moda, L. F. Secco
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Through free and fair elections and others less democratic processes, Latin America has been gradually turning into a right-wing political region. In order to understand these recent changes, this paper aims to discuss the origin and the traits of the pink wave in the subcontinent, the reasons for its current rollback and future projections for left-wing in the region. The methodology used in this paper will be descriptive and analytical combined with secondary sources mainly from the social and political sciences fields. The canons of the Washington Consensus was implemented by the majority of the Latin American governments in the 80s and 90s under the social democratic and right-wing parties. The neoliberal agenda caused political, social and economic dissatisfaction bursting into a new political configuration for the region. It started in 1998 when Hugo Chávez took the office in Venezuela through the Fifth Republic Movement under the socialist flag. From there on, Latin America was swiped by the so-called ‘pink wave’, term adopted to define the rising of self-designated left-wing or center-left parties with a progressive agenda. After Venezuela, countries like Chile, Brazil, Argentina, Uruguay, Bolivia, Equator, Nicaragua, Paraguay, El Salvador and Peru got into the pink wave. The success of these governments was due a post-neoliberal agenda focused on cash transfers programs, increasing of public spending, and the straightening of national market. The discontinuation of the preference for the left-wing started in 2012 with the coup against Fernando Lugo in Paraguay. In 2015, the chavismo in Venezuela lost the majority of the legislative seats. In 2016, an impeachment removed the Brazilian president Dilma Rousself from office who was replaced by the center-right vice-president Michel Temer. In the same year, Mauricio Macri representing the right-wing party Proposta Republicana was elected in Argentina. In 2016 center-right and liberal, Pedro Pablo Kuczynski was elected in Peru. In 2017, Sebastián Piñera was elected in Chile through the center-right party Renovación Nacional. The pink wave current rollback points towards some findings that can be arranged in two fields. Economically, the 2008 financial crisis affected the majority of the Latin American countries and the left-wing economic policies along with the end of the raw materials boom and the subsequent shrinking of economic performance opened a flank for popular dissatisfaction. In Venezuela, the 2014 oil crisis reduced the revenues for the State in more than 50% dropping social spending, creating an inflationary spiral, and consequently loss of popular support. Politically, the death of Hugo Chavez in 2013 weakened the ‘socialism of the twenty first century’ ideal, which was followed by the death of Fidel Castro, the last bastion of communism in the subcontinent. In addition, several cases of corruption revealed during the pink wave governments made the traditional politics unpopular. These issues challenge the left-wing to develop a future agenda based on innovation of its economic program, improve its legal and political compliance practices, and to regroup its electoral forces amid the social movements that supported its ascension back in the early 2000s.Keywords: Latin America, political parties, left-wing, right-wing, pink wave
Procedia PDF Downloads 2393075 Effect of Traffic Volume and Its Composition on Vehicular Speed under Mixed Traffic Conditions: A Kriging Based Approach
Authors: Subhadip Biswas, Shivendra Maurya, Satish Chandra, Indrajit Ghosh
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Use of speed prediction models sometimes appears as a feasible alternative to laborious field measurement particularly, in case when field data cannot fulfill designer’s requirements. However, developing speed models is a challenging task specifically in the context of developing countries like India where vehicles with diverse static and dynamic characteristics use the same right of way without any segregation. Here the traffic composition plays a significant role in determining the vehicular speed. The present research was carried out to examine the effects of traffic volume and its composition on vehicular speed under mixed traffic conditions. Classified traffic volume and speed data were collected from different geometrically identical six lane divided arterials in New Delhi. Based on these field data, speed prediction models were developed for individual vehicle category adopting Kriging approximation technique, an alternative for commonly used regression. These models are validated with the data set kept aside earlier for validation purpose. The predicted speeds showed a great deal of agreement with the observed values and also the model outperforms all other existing speed models. Finally, the proposed models were utilized to evaluate the effect of traffic volume and its composition on speed.Keywords: speed, Kriging, arterial, traffic volume
Procedia PDF Downloads 3513074 Effect of Installation of Long Cylindrical External Store on Performance, Stability, Control and Handling Qualities of Light Transport Aircraft
Authors: Ambuj Srivastava, Narender Singh
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This paper presents the effect of installation of cylindrical external store on the performance, stability, control and handling qualities of light transport category aircraft. A pair of long cylindrical store was installed symmetrically on either side of the fuselage (port and starboard) ahead of the wing and below the fuselage bottom surface running below pilot and co-pilot window. The cylindrical store was installed as hanging from aircraft surface through specially designed brackets. The adjoining structure was sufficiently reinforced for bearing aerodynamic loads. The length to diameter ratio of long cylindrical store was ~20. Based on academic studies and flow simulation analysis, a considerable detrimental effect on single engine second segment climb performance was found which was later validated through extensive flight testing exercise. The methodology of progressive flight envelope opening was adopted. The certification was sought from Regional airworthiness authorities and for according approval.Keywords: second segment climb, maximum operating speed, cruise performance (single engine and twin engine), minimum control speed, and additional trim required
Procedia PDF Downloads 2323073 Nonlinear Aerodynamic Parameter Estimation of a Supersonic Air to Air Missile by Using Artificial Neural Networks
Authors: Tugba Bayoglu
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Aerodynamic parameter estimation is very crucial in missile design phase, since accurate high fidelity aerodynamic model is required for designing high performance and robust control system, developing high fidelity flight simulations and verification of computational and wind tunnel test results. However, in literature, there is not enough missile aerodynamic parameter identification study for three main reasons: (1) most air to air missiles cannot fly with constant speed, (2) missile flight test number and flight duration are much less than that of fixed wing aircraft, (3) variation of the missile aerodynamic parameters with respect to Mach number is higher than that of fixed wing aircraft. In addition to these challenges, identification of aerodynamic parameters for high wind angles by using classical estimation techniques brings another difficulty in the estimation process. The reason for this, most of the estimation techniques require employing polynomials or splines to model the behavior of the aerodynamics. However, for the missiles with a large variation of aerodynamic parameters with respect to flight variables, the order of the proposed model increases, which brings computational burden and complexity. Therefore, in this study, it is aimed to solve nonlinear aerodynamic parameter identification problem for a supersonic air to air missile by using Artificial Neural Networks. The method proposed will be tested by using simulated data which will be generated with a six degree of freedom missile model, involving a nonlinear aerodynamic database. The data will be corrupted by adding noise to the measurement model. Then, by using the flight variables and measurements, the parameters will be estimated. Finally, the prediction accuracy will be investigated.Keywords: air to air missile, artificial neural networks, open loop simulation, parameter identification
Procedia PDF Downloads 2783072 An investigation of Leading Edge and Trailing Edge Corrugation for Low Reynolds Number Application
Authors: Syed Hassan Raza Shah, Mohammad Mohammad Ali
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The flow over a smoothly profiled airfoil at a low Reynolds number is highly susceptible to separate even at a very low angle of attack. An investigation was made to study the effect of leading-edge and trailing-edge corrugation with the spanwise change in the ridges resulted due to the change in the chord length for an infinite wing. The wind tunnel results using NACA0018 wings revealed that leading and trailing edge corrugation did not have any benefit in terms of aerodynamic efficiency or delayed stall. The leading edge and trailing edge corrugation didn't change the lift curve slope, with the leading edge corrugation wing stalling first in the range of Reynolds number of 50,000 to 125,000.Keywords: leading and trailing edge corrugations, low reynolds number, wind tunnel testing, NACA0018
Procedia PDF Downloads 2903071 Sensorless Controller of Induction Motor Using Backstepping Approach and Fuzzy MRAS
Authors: Ahmed Abbou
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This paper present a sensorless controller designed by the backstepping approach for the speed control of induction motor. In this strategy of control, we also combined the method Fuzzy MRAS to estimate the rotor speed and the observer type Luenburger to observe Rotor flux. The control model involves a division by the flux variable that may lead to unbounded solutions. Such a risk is avoided by basing the controller design on Lyapunov function that accounts for the model singularity. On the other hand, this mixed method gives better results in Sensorless operation and especially at low speed. The response time at 5% of the flux is 20ms while the error between the speed with sensor and the estimated speed remains in the range of ±0.8 rad/s for the rated functioning and ±1.5 rad/s for low speed.Keywords: backstepping approach, fuzzy logic, induction motor, luenburger observer, sensorless MRAS
Procedia PDF Downloads 3733070 Creative Self-efficacy and Innovation Speed of New Ventures: The Mediating Role of Entrepreneurial Bricolage
Authors: Yi-Wen Chen, Hsueh-Liang Fan
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Evidence shows that start-ups success is positively correlated with innovation speed. However, new ventures are seldom able to acquire abundant resources for new product development (NPD), which means that entrepreneurs may depend on personal creativity instead of physical investments to achieve and accelerate speed of first product launch. This study accentuates the role of entrepreneurial bricolage, which defined as making do by applying combinations of the resources at hand to new problems and opportunities, in the relations of creative self-efficacy and innovation speed. This study uses structural equation modeling to test the hypotheses in a sample of 203 start-ups operating various creative markets. Results reveal that creative self-efficacy is positively and directly associated with innovation speed, whereas entrepreneurial bricolage plays a full mediator. These findings offer important theoretical and practical implications.Keywords: creative self-efficacy, innovation speed, entrepreneurial bricolage, new ventures
Procedia PDF Downloads 5303069 Prediction of Wind Speed by Artificial Neural Networks for Energy Application
Authors: S. Adjiri-Bailiche, S. M. Boudia, H. Daaou, S. Hadouche, A. Benzaoui
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In this work the study of changes in the wind speed depending on the altitude is calculated and described by the model of the neural networks, the use of measured data, the speed and direction of wind, temperature and the humidity at 10 m are used as input data and as data targets at 50m above sea level. Comparing predict wind speeds and extrapolated at 50 m above sea level is performed. The results show that the prediction by the method of artificial neural networks is very accurate.Keywords: MATLAB, neural network, power low, vertical extrapolation, wind energy, wind speed
Procedia PDF Downloads 6913068 Belt Conveyor Dynamics in Transient Operation for Speed Control
Authors: D. He, Y. Pang, G. Lodewijks
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Belt conveyors play an important role in continuous dry bulk material transport, especially at the mining industry. Speed control is expected to reduce the energy consumption of belt conveyors. Transient operation is the operation of increasing or decreasing conveyor speed for speed control. According to literature review, current research rarely takes the conveyor dynamics in transient operation into account. However, in belt conveyor speed control, the conveyor dynamic behaviors are significantly important since the poor dynamics might result in risks. In this paper, the potential risks in transient operation will be analyzed. An existing finite element model will be applied to build a conveyor model, and simulations will be carried out to analyze the conveyor dynamics. In order to realize the soft speed regulation, Harrison’s sinusoid acceleration profile will be applied, and Lodewijks estimator will be built to approximate the required acceleration time. A long inclined belt conveyor will be studied with two major simulations. The conveyor dynamics will be given.Keywords: belt conveyor , speed control, transient operation, dynamics
Procedia PDF Downloads 3303067 Deformed Wing Virus and Varroa Destructor in the Local Honey Bee Colonies Apis mellifera intermissa in Algeria
Authors: Noureddine Adjlane, Nizar Haddad
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Deformed Wing Virus (DWV) is considered as the most prevalent virus that dangerous the honeybee health worldwide today. In this study we aimed to evaluate the impact of the virus on honeybees (Apis mellifera intermissa) mortality in Algeria and we conducted the study on samples collected from the central area in the country. We used PCR for the diagnoses of the (DWV) in the diagnosis. The results had shown a high infestation in the sampled colonies and it represented 42% of the total sample. In this study, we found a clear role of both Varroa destructor mite and DWV on hive mortality in the experimented apiary. Further studies need to be conducted in order to give soled recommendations to the beekeepers, decision makers and stockholders of the Algerian beekeeping sector.Keywords: honey bee, DWV, Varroa destructor, mortality, prevalence, infestation
Procedia PDF Downloads 4543066 Pedestrian Behavior at Signalized Intersections in Izmir, Turkey
Authors: Pelin Onelcin, Yalcin Alver
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This paper investigates the walking speed and delays of pedestrians at two signalized intersections where the vehicle speed limits are different. Data was collected during afternoon and evening peak hours on November 15, 2013 and on December 6, 2013. Observational surveys were conducted by video recording technique. Pedestrians were categorized according to their gender, group size, stuff carrying condition and age. Results showed that individuals walked fastest when the group size is taken into consideration. The smallest 15th percentile walking speed was seen in the oldest age group (over 60 years old). Pedestrians experienced high delays both at roadsides and at medians. Factors affecting the pedestrian walking speed were analyzed by ANOVA.Keywords: pedestrian delay, pedestrian walking speed, signalized crosswalk, ANOVA
Procedia PDF Downloads 3943065 Thermochemical Study of the Degradation of the Panels of Wings in a Space Shuttle by Utilization of HSC Chemistry Software and Its Database
Authors: Ahmed Ait Hou
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The wing leading edge and nose cone of the space shuttle are fabricated from a reinforced carbon/carbon material. This material attains its durability from a diffusion coating of silicon carbide (SiC) and a glass sealant. During re-entry into the atmosphere, this material is subject to an oxidizing high-temperature environment. The use of thermochemical calculations resulting at the HSC CHEMISTRY software and its database allows us to interpret the phenomena of oxidation and chloridation observed on the wing leading edge and nose cone of the space shuttle during its mission in space. First study is the monitoring of the oxidation reaction of SiC. It has been demonstrated that thermal oxidation of the SiC gives the two compounds SiO₂(s) and CO(g). In the extreme conditions of very low oxygen partial pressures and high temperatures, there is a reaction between SiC and SiO₂, leading to SiO(g) and CO(g). We had represented the phase stability diagram of Si-C-O system calculated by the use of the HSC Chemistry at 1300°C. The principal characteristic of this diagram of predominance is the line of SiC + SiO₂ coexistence. Second study is the monitoring of the chloridation reaction of SiC. The other problem encountered in addition to oxidation is the phenomenon of chloridation due to the presence of NaCl. Indeed, after many missions, the leading edge wing surfaces have exhibited small pinholes. We have used the HSC Chemistry database to analyze these various reactions. Our calculations concorde with the phenomena we announced in research work resulting in NASA LEWIS Research center.Keywords: thermochchemicals calculations, HSC software, oxidation and chloridation, wings in space
Procedia PDF Downloads 1223064 Study on the Geometric Similarity in Computational Fluid Dynamics Calculation and the Requirement of Surface Mesh Quality
Authors: Qian Yi Ooi
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At present, airfoil parameters are still designed and optimized according to the scale of conventional aircraft, and there are still some slight deviations in terms of scale differences. However, insufficient parameters or poor surface mesh quality is likely to occur if these small deviations are embedded in a future civil aircraft with a size that is quite different from conventional aircraft, such as a blended-wing-body (BWB) aircraft with future potential, resulting in large deviations in geometric similarity in computational fluid dynamics (CFD) simulations. To avoid this situation, the study on the CFD calculation on the geometric similarity of airfoil parameters and the quality of the surface mesh is conducted to obtain the ability of different parameterization methods applied on different airfoil scales. The research objects are three airfoil scales, including the wing root and wingtip of conventional civil aircraft and the wing root of the giant hybrid wing, used by three parameterization methods to compare the calculation differences between different sizes of airfoils. In this study, the constants including NACA 0012, a Reynolds number of 10 million, an angle of attack of zero, a C-grid for meshing, and the k-epsilon (k-ε) turbulence model are used. The experimental variables include three airfoil parameterization methods: point cloud method, B-spline curve method, and class function/shape function transformation (CST) method. The airfoil dimensions are set to 3.98 meters, 17.67 meters, and 48 meters, respectively. In addition, this study also uses different numbers of edge meshing and the same bias factor in the CFD simulation. Studies have shown that with the change of airfoil scales, different parameterization methods, the number of control points, and the meshing number of divisions should be used to improve the accuracy of the aerodynamic performance of the wing. When the airfoil ratio increases, the most basic point cloud parameterization method will require more and larger data to support the accuracy of the airfoil’s aerodynamic performance, which will face the severe test of insufficient computer capacity. On the other hand, when using the B-spline curve method, average number of control points and meshing number of divisions should be set appropriately to obtain higher accuracy; however, the quantitative balance cannot be directly defined, but the decisions should be made repeatedly by adding and subtracting. Lastly, when using the CST method, it is found that limited control points are enough to accurately parameterize the larger-sized wing; a higher degree of accuracy and stability can be obtained by using a lower-performance computer.Keywords: airfoil, computational fluid dynamics, geometric similarity, surface mesh quality
Procedia PDF Downloads 2213063 Characterising the Performance Benefits of a 1/7-Scale Morphing Rotor Blade
Authors: Mars Burke, Alvin Gatto
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Rotary-wing aircraft serve as indispensable components in the advancement of aviation, valued for their ability to operate in diverse and challenging environments without the need for conventional runways. This versatility makes them ideal for applications like environmental conservation, precision agriculture, emergency medical support, and rapid-response operations in rugged terrains. However, although highly maneuverable, rotary-wing platforms generally have lower aerodynamic efficiency than fixed-wing aircraft. This study takes the view of improving aerodynamic performance by examining a 1/7th scale rotor blade model with a NACA0012 airfoil using CROTOR software. The analysis focuses on optimal spanwise locations for separating morphing and fixed blade sections at 85%, 90%, and 95% of the blade radius (r/R) with up to +20 degrees of twist incorporated to the design.. Key performance metrics assessed include lift coefficient (CL), drag coefficient (CD), lift-to-drag ratio (CL / CD), Mach number, power, thrust coefficient, and Figure of Merit (FOM). Results indicate that the 0.90 r/R position is optimal for dividing the morphing and fixed sections, achieving a significant improvement of over 7% in both lift-to-drag ratio and FOM. These findings underscoring the substantial impact on overall performance of the rotor system and rotational aerodynamics that geometric modifications through the inclusion of a morphing capability can ultimately realise.Keywords: rotary morphing, rotational aerodynamics, rotorcraft morphing, rotor blade, twist morphing
Procedia PDF Downloads 103062 The Effect of Pulling and Rotation Speed on the Jet Grout Columns
Authors: İbrahim Hakkı Erkan, Özcan Tan
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The performance of jet grout columns was affected by many controlled and uncontrolled parameters. The leading parameters for the controlled ones can be listed as injection pressure, rod pulling speed, rod rotation speed, number of nozzles, nozzle diameter and Water/Cement ratio. And the uncontrolled parameters are soil type, soil structure, soil layering condition, underground water level, the changes in strength parameters and the rheologic properties of cement in time. In this study, the performance of jet grout columns and the effects of pulling speed and rotation speed were investigated experimentally. For this purpose, a laboratory type jet grouting system was designed for the experiments. Through this system, jet grout columns were produced in three different conditions. The results of the study showed that the grout pressure and the lifting speed significantly affect the performance of the jet grouting columns.Keywords: jet grout, sandy soils, soil improvement, soilcreate
Procedia PDF Downloads 2513061 Aerodynamic Analysis of Multiple Winglets for Aircrafts
Authors: S. Pooja Pragati, B. Sudarsan, S. Raj Kumar
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This paper provides a practical design of a new concept of massive Induced Drag reductions of stream vise staggered multiple winglets. It is designed to provide an optimum performance of a winglet from conventional designs. In preparing for a mechanical design, aspects such as shape, dimensions are analyzed to yield a huge amount of reduction in fuel consumption and increased performance. Owing to its simplicity of application and effectiveness we believe that it will enable us to consider its enhanced version for the grid effect of the staggered multiple winglets on the deflected mass flow of the wing system. The objective of the analysis were to compare the aerodynamic characteristics of two winglet configuration and to investigate the performance of two winglets shape simulated at selected cant angle of 0,45,60 degree.Keywords: multiple winglets, induced drag, aerodynamics analysis, low speed aircrafts
Procedia PDF Downloads 4793060 Artificial Neural Network Based Approach for Estimation of Individual Vehicle Speed under Mixed Traffic Condition
Authors: Subhadip Biswas, Shivendra Maurya, Satish Chandra, Indrajit Ghosh
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Developing speed model is a challenging task particularly under mixed traffic condition where the traffic composition plays a significant role in determining vehicular speed. The present research has been conducted to model individual vehicular speed in the context of mixed traffic on an urban arterial. Traffic speed and volume data have been collected from three midblock arterial road sections in New Delhi. Using the field data, a volume based speed prediction model has been developed adopting the methodology of Artificial Neural Network (ANN). The model developed in this work is capable of estimating speed for individual vehicle category. Validation results show a great deal of agreement between the observed speeds and the predicted values by the model developed. Also, it has been observed that the ANN based model performs better compared to other existing models in terms of accuracy. Finally, the sensitivity analysis has been performed utilizing the model in order to examine the effects of traffic volume and its composition on individual speeds.Keywords: speed model, artificial neural network, arterial, mixed traffic
Procedia PDF Downloads 3883059 An Investigation on Designing and Enhancing the Performance of H-Darrieus Wind Turbine of 10KW at the Medium Range of Wind Speed in Vietnam
Authors: Ich Long Ngo, Dinh Tai Dang, Ngoc Tu Nguyen, Minh Duc Nguyen
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This paper describes an investigation on designing and enhancing the performance of H-Darrieus wind turbine (HDWT) of 10kW at the medium wind speed. The aerodynamic characteristics of this turbine were investigated by both theoretical and numerical approaches. The optimal design procedure was first proposed to enhance the power coefficient under various effects, such as airfoil type, number of blades, solidity, aspect ratio, and tip speed ratio. As a result, the overall design of the 10kW HDWT was well achieved, and the power characteristic of this turbine was found by numerical approach. Additionally, the maximum power coefficient predicted is up to 0.41 at the tip speed ratio of 3.7 and wind speed of 8 m/s. Particularly, a generalized correlation of power coefficient with tip speed ratio and wind speed is first proposed. These results obtained are very useful for enhancing the performance of the HDWTs placed in a country with high wind power potential like Vietnam.Keywords: computational fluid dynamics, double multiple stream tube, h-darrieus wind turbine, renewable energy
Procedia PDF Downloads 1173058 Representation of the Kurdish Opposition: From Periphery to Center
Authors: Songul Miftakhov
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This study explores political representation and engagement of Eastern and Southeastern Anatolia regions, known to have dense Kurdish population and referred further to as Eastern region, in the Turkish parliament between 1946 and 1980. Traditional local notables had most of the privileges to be represented given their connectedness with political parties. Traditional local notables integrated into right-wing parties considering political and economic aspects. At the same time, they kept control over local political involvement channels. As a result, political representation and presence were monopolized at central, local and civil society levels. One part of Kurdish intellectuals was marginalized from the parliament after addressing issues in Eastern Anatolia and trying to develop solutions apart from the mainstream. Some of them took part in Kurdish oppositional left wing in the 1960s and jounced power of settled notables in 1970s in local administrations or as independent members of the parliament.Keywords: Kurdish representation, parliament, local nobles, Eastern and Southeastern Anatolia
Procedia PDF Downloads 1533057 A Theoretical Approach on Electoral Competition, Lobby Formation and Equilibrium Policy Platforms
Authors: Deepti Kohli, Meeta Keswani Mehra
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The paper develops a theoretical model of electoral competition with purely opportunistic candidates and a uni-dimensional policy using the probability voting approach while focusing on the aspect of lobby formation to analyze the inherent complex interactions between centripetal and centrifugal forces and their effects on equilibrium policy platforms. There exist three types of agents, namely, Left-wing, Moderate and Right-wing who comprise of the total voting population. Also, it is assumed that the Left and Right agents are free to initiate a lobby of their choice. If initiated, these lobbies generate donations which in turn can be contributed to one (or both) electoral candidates in order to influence them to implement the lobby’s preferred policy. Four different lobby formation scenarios have been considered: no lobby formation, only Left, only Right and both Left and Right. The equilibrium policy platforms, amount of individual donations by agents to their respective lobbies and the contributions offered to the electoral candidates have been solved for under each of the above four cases. Since it is assumed that the agents cannot coordinate each other’s actions during the lobby formation stage, there exists a probability with which a lobby would be formed, which is also solved for in the model. The results indicate that the policy platforms of the two electoral candidates converge completely under the cases of no lobby and both (extreme) formations but diverge under the cases of only one (Left or Right) lobby formation. This is because in the case of no lobby being formed, only the centripetal forces (emerging from the election-winning aspect) are present while in the case of both extreme (Left-wing and Right-wing) lobbies being formed, centrifugal forces (emerging from the lobby formation aspect) also arise but cancel each other out, again resulting in a pure policy convergence phenomenon. In contrast, in case of only one lobby being formed, both centripetal and centrifugal forces interact strategically, leading the two electoral candidates to choose completely different policy platforms in equilibrium. Additionally, it is found that in equilibrium, while the donation by a specific agent type increases with the formation of both lobbies in comparison to when only one lobby is formed, the probability of implementation of the policy being advocated by that lobby group falls.Keywords: electoral competition, equilibrium policy platforms, lobby formation, opportunistic candidates
Procedia PDF Downloads 3293056 The Influence of Variable Geometrical Modifications of the Trailing Edge of Supercritical Airfoil on the Characteristics of Aerodynamics
Authors: P. Lauk, K. E. Seegel, T. Tähemaa
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The fuel consumption of modern, high wing loading, commercial aircraft in the first stage of flight is high because the usable flight level is lower and the weather conditions (jet stream) have great impact on aircraft performance. To reduce the fuel consumption, it is necessary to raise during first stage of flight the L/D ratio value within Cl 0.55-0.65. Different variable geometrical wing trailing edge modifications of SC(2)-410 airfoil were compared at M 0.78 using the CFD software STAR-CCM+ simulation based Reynolds-averaged Navier-Stokes (RANS) equations. The numerical results obtained show that by increasing the width of the airfoil by 4% and by modifying the trailing edge airfoil, it is possible to decrease airfoil drag at Cl 0.70 for up to 26.6% and at the same time to increase commercial aircraft L/D ratio for up to 5.0%. Fuel consumption can be reduced in proportion to the increase in L/D ratio.Keywords: L/D ratio, miniflaps, mini-TED, supercritical airfoil
Procedia PDF Downloads 2053055 Conceptual and Preliminary Design of Landmine Searching UAS at Extreme Environmental Condition
Authors: Gopalasingam Daisan
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Landmines and ammunitions have been creating a significant threat to the people and animals, after the war, the landmines remain in the land and it plays a vital role in civilian’s security. Especially the Children are at the highest risk because they are curious. After all, an unexploded bomb can look like a tempting toy to an inquisitive child. The initial step of designing the UAS (Unmanned Aircraft Systems) for landmine detection is to choose an appropriate and effective sensor to locate the landmines and other unexploded ammunitions. The sensor weight and other components related to the sensor supporting device’s weight are taken as a payload weight. The mission requirement is to find the landmines in a particular area by making a proper path that will cover all the vicinity in the desired area. The weight estimation of the UAV (Unmanned Aerial Vehicle) can be estimated by various techniques discovered previously with good accuracy at the first phase of the design. The next crucial part of the design is to calculate the power requirement and the wing loading calculations. The matching plot techniques are used to determine the thrust-to-weight ratio, and this technique makes this process not only easiest but also precisely. The wing loading can be calculated easily from the stall equation. After these calculations, the wing area is determined from the wing loading equation and the required power is calculated from the thrust to weight ratio calculations. According to the power requirement, an appropriate engine can be selected from the available engine from the market. And the wing geometric parameter is chosen based on the conceptual sketch. The important steps in the wing design to choose proper aerofoil and which will ensure to create sufficient lift coefficient to satisfy the requirements. The next component is the tail; the tail area and other related parameters can be estimated or calculated to counteract the effect of the wing pitching moment. As the vertical tail design depends on many parameters, the initial sizing only can be done in this phase. The fuselage is another major component, which is selected based on the slenderness ratio, and also the shape is determined on the sensor size to fit it under the fuselage. The landing gear is one of the important components which is selected based on the controllability and stability requirements. The minimum and maximum wheel track and wheelbase can be determined based on the crosswind and overturn angle requirements. The minor components of the landing gear design and estimation are not the focus of this project. Another important task is to calculate the weight of the major components and it is going to be estimated using empirical relations and also the mass is added to each such component. The CG and moment of inertia are also determined to each component separately. The sensitivity of the weight calculation is taken into consideration to avoid extra material requirements and also reduce the cost of the design. Finally, the aircraft performance is calculated, especially the V-n (velocity and load factor) diagram for different flight conditions such as not disturbed and with gust velocity.Keywords: landmine, UAS, matching plot, optimization
Procedia PDF Downloads 1703054 Mixed Method Analysis to Propose a Policy Action against Racism and Xenophobia in India
Authors: Anwesha Das
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There are numerous cases of racism and discriminatory practices in India against the northeast citizens and the African migrants. The right-wing extremism of the presently ruling political party in India has resulted in increased cases of xenophobia and Afrophobia. The rigid Indian caste system contributes to such practices of racism. The establishment of the ‘Hindu race’ by the present right-wing government, leading to instilling pride among Hindus being of a superior race, has resulted in more atrocious racist practices. This paper argues that policy action is required against racist, discriminatory practices. Policy actors in India do not ask the right questions and fail to give the needed redirection. It critically analyses Acts 14 and 15 of the Indian constitution in order to examine the cause of a policy action. In proposing the need for policy action, this paper places its arguments as a vital extension of the existing scholarship on public policy studies in India. It uses mixed-method analysis to examine the factors responsible for the policy problem and aims to suggest specific points of intervention in a policy progression. The study finds that despite anti-discriminatory policies in the mentioned Acts of the Indian constitution, there are rampant cases of racism owing to religious and cultural factors. The major findings of the study show how the present right-wing government violated the constitution in aggravating xenophobia. This paper proposes a policy action required to stop such further practices.Keywords: India, migrants, policy action, racism, xenophobia
Procedia PDF Downloads 453053 The Influence of Surface Roughness on the Flow Fields Generated by an Oscillating Cantilever
Authors: Ciaran Conway, Nick Jeffers, Jeff Punch
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With the current trend of miniaturisation of electronic devices, piezoelectric fans have attracted increasing interest as an alternative means of forced convection over traditional rotary solutions. Whilst there exists an abundance of research on various piezo-actuated flapping fans in the literature, the geometries of these fans all consist of a smooth rectangular cross section with thicknesses typically of the order of 100 um. The focus of these studies is primarily on variables such as frequency, amplitude, and in some cases resonance mode. As a result, the induced flow dynamics are a direct consequence of the pressure differential at the fan tip as well as the pressure-driven ‘over the top’ vortices generated at the upper and lower edges of the fan. Rough surfaces such as golf ball dimples or vortex generators on an aircraft wing have proven to be beneficial by tripping the boundary layer and energising the adjacent air flow. This paper aims to examine the influence of surface roughness on the airflow generation of a flapping fan and determine whether the induced wake can be manipulated or enhanced by energising the airflow around the fan tip. Particle Image Velocimetry (PIV) is carried out on mechanically oscillated rigid fans with various surfaces consisting of pillars, perforations and cell-like grids derived from the wing topology of natural fliers. The results of this paper may be used to inform the design of piezoelectric fans and possibly aid in understanding the complex aerodynamics inherent in flapping wing flight.Keywords: aerodynamics, oscillating cantilevers, PIV, vortices
Procedia PDF Downloads 2173052 The Use of the Social Media as a Propaganda Tool from the Political Parties in Europe against the Immigrants
Authors: Gülbuğ Erol, Caner Çakı
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In Europe, it is seen that the immigrant population has increased in recent years. The rapid increase in the immigrant population has led to that some extreme right-wing parties increased their harsh discourse against the immigrants in Europe. In particular, it is seen that some right-wing parties in some European countries have demanded that the immigrant population could be controlled in the countries they are in, and even those immigrants should be removed from their countries. In this process, it is seen that these parties have effectively used social media platforms in the propaganda activities carried out for immigrants in recent years. In particular, the social media has great advantages in that these parties can address to the entire population in the country, apart from the limited masses that political parties address. How these political parties benefit from these advantages has great importance for the political parties to demonstrate their influence in political arena. In this study, it was tried to investigate how and why the extreme right-wing parties in Europe have used social media in their propaganda activities towards immigrant populations in Europe. For this purpose, the political parties of the three German-speaking countries in Europe were elected; Die Nationaldemokratische Partei Deutschlands (NPD) from Germany, Die Freiheitliche Partei Österreichs (FPÖ) from Austria, Die Schweizerische Volkspartei (SVP) from Switzerland. As social media platform, only their Facebook accounts were analyzed in this study. Accounts The political parties selected were examined with content analysis, and that social media was effectively used by extreme right-wing parties for propaganda purposes towards immigrants in Europe revealed.In this process, it is seen that these parties have effectively used social media platforms in the propaganda activities carried out for immigrants in recent years. In particular, the social media has great advantages in that these parties can address to the entire population in the country, apart from the limited masses that political parties address. How these political parties benefit from these advantages has great importance for the political parties to demonstrate their influence in political arena. In Europe, it is seen that the immigrant population has increased in recent years. The rapid increase in the immigrant population has led to that some extreme right-wing parties increased their harsh discourse against the immigrants in Europe. In particular, it is seen that some right-wing parties in some European countries have demanded that the immigrant population should be controlled in the countries they are in, and even those immigrants should be removed from their countries. In this process, it is seen that these parties have effectively used social media platforms in the propaganda activities carried out for immigrants in recent years. In particular, the social media has great advantages in that these parties can address to the entire population in the country, apart from the limited masses that political parties address. How these political parties benefit from these advantages has great importance for the political parties to demonstrate their influence in political arena. In this study, it was tried to investigate how and why the extreme right-wing parties in Europe have used social media in their propaganda activities towards immigrant populations in Europe. For this purpose, the political parties of the three German-speaking countries in Europe were elected; Die Nationaldemokratische Partei Deutschlands (NPD) from Germany, Die Freiheitliche Partei Österreichs (FPÖ) from Austria, Die Schweizerische Volkspartei (SVP) from Switzerland. As social media platform, only their Facebook accounts were analyzed in this study. Accounts The political parties selected were examined with content analysis and that social media was effectively used by extreme right-wing parties for propaganda purposes towards immigrants in Europe revealed.Keywords: content analysis, political parties, propaganda, social media
Procedia PDF Downloads 4163051 Design and Study of a Low Power High Speed 8 Transistor Based Full Adder Using Multiplexer and XOR Gates
Authors: Biswarup Mukherjee, Aniruddha Ghoshal
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In this paper, we propose a new technique for implementing a low power high speed full adder using 8 transistors. Full adder circuits are used comprehensively in Application Specific Integrated Circuits (ASICs). Thus it is desirable to have high speed operation for the sub components. The explored method of implementation achieves a high speed low power design for the full adder. Simulated results indicate the superior performance of the proposed technique over conventional 28 transistor CMOS full adder. Detailed comparison of simulated results for the conventional and present method of implementation is presented.Keywords: high speed low power full adder, 2-T MUX, 3-T XOR, 8-T FA, pass transistor logic, CMOS (complementary metal oxide semiconductor)
Procedia PDF Downloads 3483050 Effectiveness of Variable Speed Limit Signs in Reducing Crash Rates on Roadway Construction Work Zones in Alaska
Authors: Osama Abaza, Tanay Datta Chowdhury
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As a driver's speed increases, so do the probability of an incident and likelihood of injury. The presence of equipment, personnel, and a changing landscape in construction zones create greater potential for incident. This is especially concerning in Alaska, where summer construction activity, coinciding with the peak annual traffic volumes, cannot be avoided. In order to reduce vehicular speeding in work zones, and therefore the probability of crash and incident occurrence, variable speed limit (VSL) systems can be implemented in the form of radar speed display trailers since the radar speed display trailers were shown to be effective at reducing vehicular speed in construction zones. Allocation of VSL not only help reduce the 85th percentile speed but also it will predominantly reduce mean speed as well. Total of 2147 incidents along with 385 crashes occurred only in one month around the construction zone in the Alaska which seriously requires proper attention. This research provided a thorough crash analysis to better understand the cause and provide proper countermeasures. Crashes were predominantly recoded as vehicle- object collision and sideswipe type and thus significant amount of crashes fall in the group of no injury to minor injury type in the severity class. But still, 35 major crashes with 7 fatal ones in a one month period require immediate action like the implementation of the VSL system as it proved to be a speed reducer in the construction zone on Alaskan roadways.Keywords: speed, construction zone, crash, severity
Procedia PDF Downloads 249