Search results for: source flow and wall y+.

Authors: Liu Ying-jie, Lu Wen-bo, Peng Cheng-jian

Abstract:

With the development of the automotive technology and electric vehicle, the contribution of the wind noise on the interior noise becomes the main source of noise. The main transfer path which the exterior excitation is transmitted through is the greenhouse panels and side windows. Simulating the wind noise transmitted into the vehicle accurately in the early development stage can be very challenging. The basic methodologies of this study were based on the Lighthill analogy; the exterior flow field around a passenger car was computed using unsteady Computational Fluid Dynamics (CFD) firstly and then a Finite Element Method (FEM) was used to compute the interior acoustic response. The major findings of this study include: 1) The Sound Pressure Level (SPL) response at driver’s ear locations is mainly induced by the turbulence pressure fluctuation; 2) Peaks were found over the full frequency range. It is found that the methodology used in this study could predict the interior wind noise induced by the exterior aerodynamic excitation in industry.

Keywords: Wind noise, computational fluid dynamics, finite element method, passenger car.

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Authors: A. Pérard Lecomte, G. Fokoua, A. Mehel, A. Tanière

Abstract:

Automotive experimental measurements in wind tunnel are often conducted on reduced scale. Depending on the study, different similitude parameters are used by researchers to best reproduce the flow at full scale. In this paper, two parameters are investigated, which are Reynolds number and upstream velocity when dealing with airflow of typical urban speed range, below 15 m.s-1. Their impact on flow structures and aerodynamic drag in the wake of a heavy truck model are explored. To achieve this, Computational Fluid Dynamics (CFD) simulations have been conducted with the aim of modeling the wake airflow of full- and reduced-scaled heavy trucks (1/4 and 1/28). The Reynolds Average Navier-Stokes (RANS) approach combined to the Reynolds Stress Model (RSM) as the turbulence model closure was used. Both drag coefficients and upstream velocity profiles (flow topology) were found to be close one another for the three investigated scales, when the dynamical similitude Reynolds is achieved. Moreover, the difference is weak for the simulations based on the same inlet air velocity. Hence, for the relative low velocity range investigated here, the impact of the scale factor is limited.

Keywords: Aerodynamics, CFD, heavy truck, recirculation area, scale effects, similitude parameters.

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Authors: Dia I. Abu-Al-Nadi, M. J. Mismar, T. H. Ismail

Abstract:

A technique for estimating the direction-of-arrival (DOA) of unknown number of source signals is presented using the eigen-approach. The eigenvector corresponding to the minimum eigenvalue of the autocorrelation matrix yields the minimum output power of the array. Also, the array polynomial with this eigenvector possesses roots on the unit circle. Therefore, the pseudo-spectrum is found by perturbing the phases of the roots one by one and calculating the corresponding array output power. The results indicate that the DOAs and the number of source signals are estimated accurately in the presence of a wide range of input noise levels.

Keywords: Array signal processing, direction-of-arrival, antenna arrays, eigenvalues, eigenvectors.

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Authors: Lukas Horny, Rudolf Zitny, Hynek Chlup, Tomas Adamek, Michal Sara

Abstract:

An inflation–extension test with human vena cava inferior was performed with the aim to fit a material model. The vein was modeled as a thick–walled tube loaded by internal pressure and axial force. The material was assumed to be an incompressible hyperelastic fiber reinforced continuum. Fibers are supposed to be arranged in two families of anti–symmetric helices. Considered anisotropy corresponds to local orthotropy. Used strain energy density function was based on a concept of limiting strain extensibility. The pressurization was comprised by four pre–cycles under physiological venous loading (0 – 4kPa) and four cycles under nonphysiological loading (0 – 21kPa). Each overloading cycle was performed with different value of axial weight. Overloading data were used in regression analysis to fit material model. Considered model did not fit experimental data so good. Especially predictions of axial force failed. It was hypothesized that due to nonphysiological values of loading pressure and different values of axial weight the material was not preconditioned enough and some damage occurred inside the wall. A limiting fiber extensibility parameter Jm was assumed to be in relation to supposed damage. Each of overloading cycles was fitted separately with different values of Jm. Other parameters were held the same. This approach turned out to be successful. Variable value of Jm can describe changes in the axial force – axial stretch response and satisfy pressure – radius dependence simultaneously.

Keywords: Constitutive model, damage, fiber reinforcedcomposite, limiting fiber extensibility, preconditioning, vena cavainferior.

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Authors: Hussain H. Al-Kayiem, Ahmed K. Hussein, Toh Seng Peow

Abstract:

The evaluation of the convective heat transfer of flow in passages with rectangular cross section is still of interest for the heat transfer investigators, as in the air heater solar collectors. The aim of this paper is to present investigation results on the natural convection heat transfer in a solar air heater. The effect of the channel length as heat transfer surface and the inclination of the passage were investigated. The results were obtained experimentally and theoretically. For that, an experimental test rig was fabricated with channel lengths of 1m, 1.5m, and 2m. For each length, the air outlet and inlet temperatures, absorber and cover temperatures, solar radiation intensity and air flow rate were measured at 10o, 30o, 50o, 70o, and 90o tilt angles. Measurements were recorded every 2 hours interval to investigate the transient behavior of the system. The experimental and theoretical results are presented in terms of Nu number versus Ra number and discussed. The percentages of differences between experimental and theoretical results are within the margin of 6% to 13%, effectively. It is recommended to extend the investigation to study the same configurations with different artificial surface roughing by ribs or pins.

Keywords: Convective heat transfer, Flat plate, Natural convection, Passage flow, Solar energy.

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Authors: Ali Z a'fari

Abstract:

Voltage flicker is a disturbance in electrical power systems. The reason for this disturbance is mainly the large nonlinear loads such as electric arc furnaces. Synchronous static compensator (STATCOM) is considered as a proper technique to mitigate the voltage flicker. Application of more suitable and precise power electronic converter leads to a more precise performance of the compensator. In this paper a three-level 12-pulse voltage source inverter (VSI) with a 12-terminal transformer connected to the ac system is studied and the obtained results are compared with the performance of a STATCOM using a simple two-level VSI and an optimal and more precise performance of the proposed scheme is achieved.

Keywords: Flicker mitigation, STATCOM, Inverter, 12-pulse, 3- level

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Authors: Roslinda Nazar, Amin Noor, Khamisah Jafar, Ioan Pop

Abstract:

In this paper, the steady laminar three-dimensional boundary layer flow and heat transfer of a copper (Cu)-water nanofluid in the vicinity of a permeable shrinking flat surface in an otherwise quiescent fluid is studied. The nanofluid mathematical model in which the effect of the nanoparticle volume fraction is taken into account is considered. The governing nonlinear partial differential equations are transformed into a system of nonlinear ordinary differential equations using a similarity transformation which is then solved numerically using the function bvp4c from Matlab. Dual solutions (upper and lower branch solutions) are found for the similarity boundary layer equations for a certain range of the suction parameter. A stability analysis has been performed to show which branch solutions are stable and physically realizable. The numerical results for the skin friction coefficient and the local Nusselt number as well as the velocity and temperature profiles are obtained, presented and discussed in detail for a range of various governing parameters.

Keywords: Heat Transfer, Nanofluid, Shrinking Surface, Stability Analysis, Three-Dimensional Flow.

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Authors: Young-Tae Lee, Hee-Chang Lim

Abstract:

This paper presents the performance characteristics of Darrieus-type vertical axis wind turbine (VAWT) with NACA airfoil blades. The performance of Darrieus-type VAWT can be characterized by torque and power. There are various parameters affecting the performance such as chord length, helical angle, pitch angle and rotor diameter. To estimate the optimum shape of Darrieustype wind turbine in accordance with various design parameters, we examined aerodynamic characteristics and separated flow occurring in the vicinity of blade, interaction between flow and blade, and torque and power characteristics derived from it. For flow analysis, flow variations were investigated based on the unsteady RANS (Reynolds-averaged Navier-Stokes) equation. Sliding mesh algorithm was employed in order to consider rotational effect of blade. To obtain more realistic results we conducted experiment and numerical analysis at the same time for three-dimensional shape. In addition, several parameters (chord length, rotor diameter, pitch angle, and helical angle) were considered to find out optimum shape design and characteristics of interaction with ambient flow. Since the NACA airfoil used in this study showed significant changes in magnitude of lift and drag depending on an angle of attack, the rotor with low drag, long cord length and short diameter shows high power coefficient in low tip speed ratio (TSR) range. On the contrary, in high TSR range, drag becomes high. Hence, the short-chord and long-diameter rotor produces high power coefficient. When a pitch angle at which airfoil directs toward inside equals to -2° and helical angle equals to 0°, Darrieus-type VAWT generates maximum power.

Keywords: Darrieus wind turbine, VAWT, NACA airfoil, performance.

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Authors: Suprijanto, Linda Sari, Vebi Nadhira , IGN. Merthayasa. Farida I.M

Abstract:

Detection of human emotions has many potential applications. One of application is to quantify attentiveness audience in order evaluate acoustic quality in concern hall. The subjective audio preference that based on from audience is used. To obtain fairness evaluation of acoustic quality, the research proposed system for multimodal emotion detection; one modality based on brain signals that measured using electroencephalogram (EEG) and the second modality is sequences of facial images. In the experiment, an audio signal was customized which consist of normal and disorder sounds. Furthermore, an audio signal was played in order to stimulate positive/negative emotion feedback of volunteers. EEG signal from temporal lobes, i.e. T3 and T4 was used to measured brain response and sequence of facial image was used to monitoring facial expression during volunteer hearing audio signal. On EEG signal, feature was extracted from change information in brain wave, particularly in alpha and beta wave. Feature of facial expression was extracted based on analysis of motion images. We implement an advance optical flow method to detect the most active facial muscle form normal to other emotion expression that represented in vector flow maps. The reduce problem on detection of emotion state, vector flow maps are transformed into compass mapping that represents major directions and velocities of facial movement. The results showed that the power of beta wave is increasing when disorder sound stimulation was given, however for each volunteer was giving different emotion feedback. Based on features derived from facial face images, an optical flow compass mapping was promising to use as additional information to make decision about emotion feedback.

Keywords: Multimodal Emotion Detection, EEG, Facial Image, Optical Flow, compass mapping, Brain Wave

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Authors: S. Maheswari, P. Arockia Jansi Rani

Abstract:

Human action is recognized directly from the video sequences. The objective of this work is to recognize various human actions like run, jump, walk etc. Human action recognition requires some prior knowledge about actions namely, the motion estimation, foreground and background estimation. Region of interest (ROI) is extracted to identify the human in the frame. Then, optical flow technique is used to extract the motion vectors. Using the extracted features similarity measure based classification is done to recognize the action. From experimentations upon the Weizmann database, it is found that the proposed method offers a high accuracy.

Keywords: Background subtraction, human silhouette, optical flow, classification.

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Authors: Irtaza M. Syed, Kaamran Raahemifar

Abstract:

This paper presents a model predictive control (MPC) of a utility interactive three phase inverter (TPI) for a photovoltaic (PV) system at commercial level. The proposed model uses phase locked loop (PLL) to synchronize the TPI with the power electric grid (PEG) and performs MPC control in a dq reference frame. TPI model consists of a boost converter (BC), maximum power point tracking (MPPT) control, and a three-leg voltage source inverter (VSI). The operational model of VSI is used to synthesize the sinusoidal current and track the reference. The model is validated using a 35.7 kW PV system in Matlab/Simulink. Implementation results show simplicity and accuracy, as well as reliability of the model.

Keywords: Model predictive control, three phase voltage source inverter, PV system, Matlab/Simulink.

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Authors: Chih-Chung Chang, Sy-Chi Kuo, Chen-Kang Huang, Sih-Li Chen

Abstract:

This study experimentally and numerically investigates motor cooling performance. The motor consists of a centrifugal fan, two axial fans, a shaft, a stator, a rotor and a heat exchanger with 637 cooling tubes. The pressure rise-flow rate (P-Q) performance curves of the cooling fans at 1800 rpm are tested using a test apparatus complying with the Chinese National Standard (CNS) 2726. Compared with the experimental measurements, the numerical analysis results show that the P-Q performance curves of the axial fan and centrifugal fan can be estimated within about 2% and 6%, respectively. By using the simplified model, setting up the heat exchanger and stator as porous media, the flow field in the motor is calculated. By using the results of the flow field near the rotor and stator, and subjecting the heat generation rate as a boundary condition, the temperature distributions of the stator and rotor are also calculated. The simulation results show that the calculated temperature of the stator winding near the axial fans is lower by about 5% than the measured value, and the calculated temperature of the stator core located at the center of the stator is about 1% higher than the measured value. Besides, discussion is made to improve the motor cooling performance.

Keywords: Motor cooling, P-Q performance curves, CNS, porous media.

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Authors: Soumia Ichoua

Abstract:

In this paper, we investigate the strategic stochastic air traffic flow management problem which seeks to balance airspace capacity and demand under weather disruptions. The goal is to reduce the need for myopic tactical decisions that do not account for probabilistic knowledge about the NAS near-future states. We present and discuss a scenario-based modeling approach based on a time-space stochastic process to depict weather disruption occurrences in the NAS. A solution framework is also proposed along with a distributed implementation aimed at overcoming scalability problems. Issues related to this implementation are also discussed.

Keywords: Air traffic management, sample average approximation, scenario-based approach, stochastic capacity.

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Authors: Riki Mukhaiyar

Abstract:

The integration between technology of remote sensing, information from the data of digital image, and modeling technology for the simulation of water quality will provide easiness during the observation on the quality of water changes on the river surface. For example, Ciliwung River which is contaminated with non-point source pollutant from household wastes, particularly on its downstream. This fact informed that the quality of water in this river is getting worse. The land use for settlements and housing ranges between 62.84% - 81.26% on the downstream of Ciliwung River, give a significant picture in seeing factors that affected the water quality of Ciliwung River.

Keywords: Digital Image, Digitize, Landuse, Non-Point SourcePollutant, Qual2e Simulation

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Authors: Mansour I. Abbadi, Abdel-Rahman M. Jaradat

Abstract:

In this paper, a technique is proposed to implement an artificial voltage-controlled capacitance or inductance which can replace the well-known varactor diode in many applications. The technique is based on injecting the current of a voltage-controlled current source onto a fixed capacitor or inductor. Then, by controlling the transconductance of the current source by an external bias voltage, a voltage-controlled capacitive or inductive reactance is obtained. The proposed voltage-controlled reactance devices can be designed to work anywhere in the frequency spectrum. Practical circuits for the proposed voltage-controlled reactances are suggested and simulated.

Keywords: voltage-controlled capacitance, voltage-controlled inductance, varactor diode, variable transconductance.

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Authors: Vishnu Raj, Chockalingam Prathap

Abstract:

The objective of this study was to explore the impact of variation in the exit annular area on the local flow field features and the flame stability of an annular premixed swirl burner (unconfined) operated with a premixed n-butane air mixture at an equivalence ratio (Φ) = 1, 1 bar, and 300K. A swirl burner with an axial swirl generator having a swirl number of 1.5 was used. Three different burner heads were chosen to have the exit area increased from 100%, 160%, and 220% resulting in inner and outer diameters and cross-sectional areas as (1) 10 mm & 15 mm, 98 mm2 (2) 17.5 mm & 22.5 mm, 157 mm2 and (3) 25 mm & 30 mm, 216 mm2. The bulk velocity and Reynolds number based on the hydraulic diameter and unburned gas properties were kept constant at 12 m/s and 4000. (i) Planar Particle Image Velocimetry (PIV) with TiO2 seeding particles and (ii) CH* chemiluminescence was used to measure the velocity fields and reaction zones of the swirl flames at 5 Hz, respectively. Velocity fields and the jet spreading rates measured at the isothermal and reactive conditions revealed that the presence of a flame significantly altered the flow field in the radial direction due to the gas expansion. Important observations from the flame measurements were: the height and maximum width of the recirculation bubbles normalized by the hydraulic diameter, and the jet spreading angles for the flames for the three exit area cases were: (a) 4.52, 1.95, 34◦, (b) 6.78, 2.37, 26◦, and (c) 8.73, 2.32, 22◦. The lean blowout (LBO) was also measured, and the respective equivalence ratios were: 0.80, 0.92, and 0.82. LBO was relatively narrow for the 157 mm2 case. For this case, PIV measurements showed that Turbulent Kinetic Energy and turbulent intensity were relatively high compared to the other two cases, resulting in higher stretch rates and narrower LBO.

Keywords: Chemiluminescence, jet spreading rate, lean blow out, swirl flow.

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Authors: Humayun Rashid, Lin Zhao

Abstract:

Retention in the IT profession is critical for organizations to stay competitive and operate reliably in the dynamic business environment. Most organizations rely on compensation and rewards as primary tools to enhance retention of employees. In this quantitative survey-based study conducted at a large global bank, we analyze the perceptions of 575 information technology (IT) software professionals in India and Malaysia and find that fairness of rewards has very little impact on retention likelihood. It is far more important to actively involve employees in organizational activities. In addition, our findings indicate that involvement is far more important than information flow: the typical organizational communication to keep employees informed.

Keywords: fairness of rewards, information flow, informationinvolvement, retention

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Authors: Muhammad Yamin Younis, Muhammad Amjad Sohail, Tawfiqur Rahman, Zaka Muhammad, Saifur Rahman Bakaul

Abstract:

The performance of Advection Upstream Splitting Method AUSM schemes are evaluated against experimental flow fields at different Mach numbers and results are compared with experimental data of subsonic, supersonic and hypersonic flow fields. The turbulent model used here is SST model by Menter. The numerical predictions include lift coefficient, drag coefficient and pitching moment coefficient at different mach numbers and angle of attacks. This work describes a computational study undertaken to compute the Aerodynamic characteristics of different air vehicles configurations using a structured Navier-Stokes computational technique. The CFD code bases on the idea of upwind scheme for the convective (convective-moving) fluxes. CFD results for GLC305 airfoil and cone cylinder tail fined missile calculated on above mentioned turbulence model are compared with the available data. Wide ranges of Mach number from subsonic to hypersonic speeds are simulated and results are compared. When the computation is done by using viscous turbulence model the above mentioned coefficients have a very good agreement with the experimental values. AUSM scheme is very efficient in the regions of very high pressure gradients like shock waves and discontinuities. The AUSM versions simulate the all types of flows from lower subsonic to hypersonic flow without oscillations.

Keywords: Subsonic, supersonic, Hypersonic, AUSM+, Drag Coefficient, lift Coefficient, Pitching moment coefficient, pressure Coefficient, turbulent flow.

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Authors: A. Chakraborty, T. Gupta

Abstract:

Several studies have shown the association between ambient particulate matter (PM) and adverse health effects and climate change, thus highlighting the need to limit the anthropogenic sources of PM. PM Exposure is commonly monitored as mass concentration of PM10 (particle aerodynamic diameter < 10μm) or PM2.5 (particle aerodynamic diameter < 2.5μm), although increasing toxicity with decreasing aerodynamic diameter has been reported due to increased surface area and enhanced chemical reactivity with other species. Additionally, the light scattering properties of PM increases with decreasing size. Hence, it is important to study the chemical characterization of finer fraction of the particulate matter and to identify their sources so that they can be controlled appropriately to a large extent at the sources before reaching to the receptors.

Keywords: PM1, PCA, source apportionment.

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Authors: Samy M. El-Behery, W. A. El-Askary, K. A. Ibrahim, Mofreh H. Hamed

Abstract:

A steady two-phase flow model has been developed to simulate the drying process of porous particle in a pneumatic conveying dryer. The model takes into account the momentum, heat and mass transfer between the continuous phase and the dispersed phase. A single particle model was employed to calculate the evaporation rate. In this model the pore structure is simplified to allow the dominant evaporation mechanism to be readily identified at all points within the duct. The predominant mechanism at any time depends upon the pressure, temperature and the diameter of pore from which evaporating is occurring. The model was validated against experimental studies of pneumatic transport at low and high speeds as well as pneumatic drying. The effects of operating conditions on the dryer parameters are studied numerically. The present results show that the drying rate is enhanced as the inlet gas temperature and the gas flow rate increase and as the solid mass flow rate deceases. The present results also demonstrate the necessity of measuring the inlet gas velocity or the solid concentration in any experimental analysis.

Keywords: Two-phase, gas-solid, pneumatic drying, pneumatic conveying, heat and mass transfer

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Authors: Muhibul Haque Bhuyan, Quazi D. M. Khosru

Abstract:

Carriers scattering in the inversion channel of n- MOSFET dominates the drain current. This paper presents an effective electron mobility model for the pocket implanted nano scale n-MOSFET. The model is developed by using two linear pocket profiles at the source and drain edges. The channel is divided into three regions at source, drain and central part of the channel region. The total number of inversion layer charges is found for these three regions by numerical integration from source to drain ends and the number of depletion layer charges is found by using the effective doping concentration including pocket doping effects. These two charges are then used to find the effective normal electric field, which is used to find the effective mobility model incorporating the three scattering mechanisms, such as, Coulomb, phonon and surface roughness scatterings as well as the ballistic phenomena for the pocket implanted nano-scale n-MOSFET. The simulation results show that the derived mobility model produces the same results as found in the literatures.

Keywords: Linear Pocket Profile, Pocket Implanted n-MOSFET, Effective Electric Field and Effective Mobility Model.

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Authors: L. N. Corîci, A. E. Frissen, D -J. Van Zoelen, I. F. Eggen, F. Peter, C. M. Davidescu, C. G. Boeriu

Abstract:

Two commercial proteases from Bacillus licheniformis (Alcalase 2.4 L FG and Alcalase 2.5 L, Type DX) were screened for the production of Z-Ala-Phe-NH2 in batch reaction. Alcalase 2.4 L FG was the most efficient enzyme for the C-terminal amidation of Z-Ala-Phe-OMe using ammonium carbamate as ammonium source. Immobilization of protease has been achieved by the sol-gel method, using dimethyldimethoxysilane (DMDMOS) and tetramethoxysilane (TMOS) as precursors (unpublished results). In batch production, about 95% of Z-Ala-Phe-NH2 was obtained at 30°C after 24 hours of incubation. Reproducibility of different batches of commercial Alcalase 2.4 L FG preparations was also investigated by evaluating the amidation activity and the entrapment yields in the case of immobilization. A packed-bed reactor (0.68 cm ID, 15.0 cm long) was operated successfully for the continuous synthesis of peptide amides. The immobilized enzyme retained the initial activity over 10 cycles of repeated use in continuous reactor at ambient temperature. At 0.75 mL/min flow rate of the substrate mixture, the total conversion of Z-Ala-Phe-OMe was achieved after 5 hours of substrate recycling. The product contained about 90% peptide amide and 10% hydrolysis byproduct.

Keywords: packed-bed reactor, peptide amide, protease, sol-gel immobilization.

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Authors: Arash Mir Abdolah Lavasani, Hamidreza Bayat

Abstract:

In this paper flow around two cam shaped cylinders had been studied numerically. The equivalent diameter of cylinders is 27.6 mm. The space between center to center of two cam shaped cylinders is define as longitudinal pitch ratio and it varies in range of 2 varies in range of 50 both cylinders depends on pitch ratio. However drag coefficient of downstream cylinder is more dependent on the pitch ratio.

Keywords: Cam shaped, tandem cylinders, numerical, drag coefficient.

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Authors: T. V. K. Gupta, J. Ramkumar, Puneet Tandon, N. S. Vyas

Abstract:

Abrasive Water Jet Machining is an unconventional machining process well known for machining hard to cut materials. The primary research focus on the process was for through cutting and a very limited literature is available on pocket milling using AWJM. The present work is an attempt to use this process for milling applications considering a set of various process parameters. Four different input parameters, which were considered by researchers for part separation, are selected for the above application, i.e., abrasive size, flow rate, standoff distance and traverse speed. Pockets of definite size are machined to investigate surface roughness, material removal rate and pocket depth. Based on the data available through experiments on SS304 material, it is observed that higher traverse speeds gives a better finish because of reduction in the particle energy density and lower depth is also observed. Increase in the standoff distance and abrasive flow rate reduces the rate of material removal as the jet loses its focus and occurrence of collisions within the particles. ANOVA for individual output parameter has been studied to know the significant process parameters.

Keywords: Abrasive flow rate, surface finish, abrasive size, standoff distance, traverse speed.

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Authors: Rabeb Triki, Hassene Djemel, Mounir Baccar

Abstract:

Surface scraping is a passive heat transfer enhancement technique that is directly used in scraped surface heat exchanger (SSHE). The scraping action prevents the accumulation of the product on the inner wall, which intensifies the heat transfer and avoids the formation of dead zones. SSHEs are widely used in industry for several applications such as crystallization, sterilization, freezing, gelatinization, and many other continuous processes. They are designed to deal with products that are viscous, sticky or that contain particulate matter. This research work presents a three-dimensional numerical simulation of the coupled thermal and hydrodynamic behavior within a SSHE which includes Archimedes’ screw instead of scraper blades. The finite volume Fluent 15.0 was used to solve continuity, momentum and energy equations using multiple reference frame formulation. The process fluid investigated under this study is the pure glycerin. Different geometrical parameters were studied in the case of steady, non-isothermal, laminar flow. In particular, attention is focused on the effect of the conicity of the rotor and the pitch of Archimedes’ screw on temperature and velocity distribution and heat transfer rate. Numerical investigations show that the increase of the number of turns in the screw from five to seven turns leads to amelioration of heat transfer coefficient, and the increase of the conicity of the rotor from 0.1 to 0.15 leads to an increase in the rate of heat transfer. Further studies should investigate the effect of different operating parameters (axial and rotational Reynolds number) on the hydrodynamic and thermal behavior of the SSHE.

Keywords: ANSYS-Fluent, hydrodynamic behavior, SSHE, thermal behavior.

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Authors: A. Аndreev, Yu. Rozhdestvenskii, К. Platonov, R. Salomaa

Abstract:

This paper considers various channels of gammaquantum generation via an ultra-short high-power laser pulse interaction with different targets.We analyse the possibilities to create a pulsed gamma-radiation source using laser triggering of some nuclear reactions and isomer targets. It is shown that sub-MeV monochromatic short pulse of gamma-radiation can be obtained with pulse energy of sub-mJ level from isomer target irradiated by intense laser pulse. For nuclear reaction channel in light- atom materials, it is shown that sub-PW laser pulse gives rise to formation about million gamma-photons of multi-MeV energy.

Keywords: High power laser, short pulse, fast particles, isomertarget.

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Authors: Ji Xi, Cheng Song Chin, Ehsan Mesbahi

Abstract:

Structure-borne noise is an important aspect of offshore platform sound field. It can be generated either directly by vibrating machineries induced mechanical force, indirectly by the excitation of structure or excitation by incident airborne noise. Therefore, limiting of the transmission of vibration energy throughout the offshore platform is the key to control the structureborne noise. This is usually done by introducing damping treatment to the steel structures. Two types of damping treatment using onboard are presented. By conducting a Statistical Energy Analysis (SEA) simulation on a jack-up rig, the noise level in the source room, the neighboring rooms, and remote living quarter cabins are compared before and after the damping treatments been applied. The results demonstrated that, in the source neighboring room and living quarter area, there is a significant noise reduction with the damping treatment applied, whereas in the source room where air-borne sound predominates that of structure-borne sound, the impact is not obvious. The conclusion on effective damping treatment in the offshore platform is made which enable acoustic professionals to implement noise control during the design stage for offshore crews’ hearing protection and habitant comfortability.

Keywords: Statistical energy analysis, damping treatment, noise control, offshore platform.

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Authors: Zong Chen

Abstract:

Motion estimation is a key problem in video processing and computer vision. Optical flow motion estimation can achieve high estimation accuracy when motion vector is small. Three-step search algorithm can handle large motion vector but not very accurate. A joint algorithm was proposed in this paper to achieve high estimation accuracy disregarding whether the motion vector is small or large, and keep the computation cost much lower than full search.

Keywords: Motion estimation, Block Matching, Optical flow, Three step search.

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Authors: R. Chimchang, R. Tongta, R. Phatthanakun

Abstract:

Inthis paper, design and fabrication of vertical micromirror for optical switching applications of single mode optical fibers are proposed. The structure of micromirror will be created from negative photoresist (SU-8) on X-ray lithography using X-ray from synchrotron light source. The properties of X-ray from synchrotron light source are high-energy electrons which can construct materials that have a high aspect ratio. In addition, the technique of gold coating of reflective material has been used for change direction of light between two pairs of optical fibers. At a wavelength of 1310 nm with minimum average loss of 5.305 dB is obtained.

Keywords: vertical micromirror, negative photoresist, X-ray lithography

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Authors: Reza Maddahian, Bijan Farhanieh, Simin Dokht Saemi

Abstract:

In this research the separation efficiency of deoiling hydrocyclone is evaluated using three-dimensional simulation of multiphase flow based on Eulerian-Eulerian finite volume method. The mixture approach of Reynolds Stress Model is also employed to capture the features of turbulent multiphase swirling flow. The obtained separation efficiency of Colman's design is compared with available experimental data and showed that the separation curve of deoiling hydrocyclones can be predicted using numerical simulation.

Keywords: Deoiling hydrocyclone, Eulerian-Eulerian Model, Numerical simulation, Separation efficiency, Reynolds Stress Model

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