Search results for: binary spray and wait
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1057

Search results for: binary spray and wait

1057 Study on the Efficient Routing Algorithms in Delay-Tolerant Networks

Authors: Si-Gwan Kim

Abstract:

In Delay Tolerant Networks (DTN), there may not exist an end-to-end path between source and destination at the time of message transmission. Employing ‘Store Carry and Forward’ delivery mechanism for message transmission in such networks usually incurs long message delays. In this paper, we present the modified Binary Spray and Wait (BSW) routing protocol that enhances the performance of the original one. Our proposed algorithm adjusts the number of forward messages depending on the number of neighbor nodes. By using beacon messages periodically, the number of neighbor nodes can be managed. The simulation using ONE simulator results shows that our modified version gives higher delivery ratio and less latency as compared to BSW.

Keywords: delay tolerant networks, store carry and forward, one simulator, binary spray and wait

Procedia PDF Downloads 94
1056 Cold Spray Coating and Its Application for High Temperature

Authors: T. S. Sidhu

Abstract:

Amongst the existing coatings methods, the cold spray is new upcoming process to deposit coatings. As from the name itself, the cold spray coating takes place at very low temperature as compare to other thermal spray coatings. In all other thermal spray coating process the partial melting of the coating powder particles takes place before deposition, but cold spray process takes place in solid state. In cold spray process, the bonding of coating power with substrate is not metallurgical as in other thermal spray processes. Due to supersonic speed and less temperature of spray particles, solid state, dense, and oxide free coatings are produced. Due to these characteristics, the cold spray coatings have been used to protect the materials against hot corrosion. In the present study, the cold spray process, cold spray fundaments, its types, and its applications for high temperatures are discussed in the light of presently available literature. In addition, the assessment of cold spray with the competitive technologies has been conferred with available literature.

Keywords: cold spray coating, hot corrosion, thermal spray coating, high-temperature materials

Procedia PDF Downloads 205
1055 Fluid Flow and Heat Transfer Characteristics Investigation in Spray Cooling Systems Using Nanofluids

Authors: Lee Derk Huan, Nur Irmawati

Abstract:

This paper aims to investigate the heat transfer and fluid flow characteristics of nanofluids used in spray cooling systems. The effect of spray height, type of nanofluids and concentration of nanofluids are numerically investigated. Five different nanofluids such as AgH2O, Al2O3, CuO, SiO2 and TiO2 with volume fraction range of 0.5% to 2.5% are used. The results revealed that the heat transfer performance decreases as spray height increases. It is found that TiO2 has the highest transfer coefficient among other nanofluids. In dilute spray conditions, low concentration of nanofluids is observed to be more effective in heat removal in a spray cooling system.

Keywords: numerical investigation, spray cooling, heat transfer, nanofluids

Procedia PDF Downloads 436
1054 Quantitative Characterization of Single Orifice Hydraulic Flat Spray Nozzle

Authors: Y. C. Khoo, W. T. Lai

Abstract:

The single orifice hydraulic flat spray nozzle was evaluated with two global imaging techniques to characterize various aspects of the resulting spray. The two techniques were high resolution flow visualization and Particle Image Velocimetry (PIV). A CCD camera with 29 million pixels was used to capture shadowgraph images to realize ligament formation and collapse as well as droplet interaction. Quantitative analysis was performed to give the sizing information of the droplets and ligaments. This camera was then applied with a PIV system to evaluate the overall velocity field of the spray, from nozzle exit to droplet discharge. PIV images were further post-processed to determine the inclusion angle of the spray. The results from those investigations provided significant quantitative understanding of the spray structure. Based on the quantitative results, detailed understanding of the spray behavior was achieved.

Keywords: spray, flow visualization, PIV, shadowgraph, quantitative sizing, velocity field

Procedia PDF Downloads 354
1053 Performance Comparison of Non-Binary RA and QC-LDPC Codes

Authors: Ni Wenli, He Jing

Abstract:

Repeat–Accumulate (RA) codes are subclass of LDPC codes with fast encoder structures. In this paper, we consider a nonbinary extension of binary LDPC codes over GF(q) and construct a non-binary RA code and a non-binary QC-LDPC code over GF(2^4), we construct non-binary RA codes with linear encoding method and non-binary QC-LDPC codes with algebraic constructions method. And the BER performance of RA and QC-LDPC codes over GF(q) are compared with BP decoding and by simulation over the Additive White Gaussian Noise (AWGN) channels.

Keywords: non-binary RA codes, QC-LDPC codes, performance comparison, BP algorithm

Procedia PDF Downloads 347
1052 Sea-Spray Calculations Using the MESO-NH Model

Authors: Alix Limoges, William Bruch, Christophe Yohia, Jacques Piazzola

Abstract:

A number of questions arise concerning the long-term impact of the contribution of marine aerosol fluxes generated at the air-sea interface on the occurrence of intense events (storms, floods, etc.) in the coastal environment. To this end, knowledge is needed on sea-spray emission rates and the atmospheric dynamics of the corresponding particles. Our aim is to implement the mesoscale model MESO-NH on the study area using an accurate sea-spray source function to estimate heat fluxes and impact on the precipitations. Based on an original and complete sea-spray source function, which covers a large size spectrum since taking into consideration the sea-spray produced by both bubble bursting and surface tearing process, we propose a comparison between model simulations and experimental data obtained during an oceanic scientific cruise on board the navy ship Atalante. The results show the relevance of the sea-spray flux calculations as well as their impact on the heat fluxes and AOD.

Keywords: atmospheric models, sea-spray source, sea-spray dynamics, aerosols

Procedia PDF Downloads 122
1051 Effect of Humidity on In-Process Crystallization of Lactose During Spray Drying

Authors: Amirali Ebrahimi, T. A. G. Langrish

Abstract:

The effect of various humidities on process yields and degrees of crystallinity for spray-dried powders from spray drying of lactose with humid air in a straight-through system have been studied. It has been suggested by Williams–Landel–Ferry kinetics (WLF) that a higher particle temperature and lower glass-transition temperature would increase the crystallization rate of the particles during the spray-drying process. Freshly humidified air produced by a Buchi-B290 spray dryer as a humidifier attached to the main spray dryer decreased the particle glass-transition temperature (Tg), while allowing the particle temperature (Tp) to reach higher values by using an insulated drying chamber. Differential scanning calorimetry (DSC) and moisture sorption analysis were used to measure the degree of crystallinity for the spray-dried lactose powders. The results showed that higher Tp-Tg, as a result of applying humid air, improved the process yield from 21 ± 4 to 26 ± 2% and crystallinity of the particles by decreasing the latent heat of crystallization from 43 ± 1 to 30 ± 11 J/g and the sorption peak height from 7.3 ± 0.7% to 6 ± 0.7%.

Keywords: lactose, crystallization, spray drying, humid air

Procedia PDF Downloads 397
1050 Teaching the Binary System via Beautiful Facts from the Real Life

Authors: Salem Ben Said

Abstract:

In recent times the decimal number system to which we are accustomed has received serious competition from the binary number system. In this note, an approach is suggested to teaching and learning the binary number system using examples from the real world. More precisely, we will demonstrate the utility of the binary system in describing the optimal strategy to win the Chinese Nim game, and in telegraphy by decoding the hidden message on Perseverance’s Mars parachute written in the language of binary system. Finally, we will answer the question, “why do modern computers prefer the ternary number system instead of the binary system?”. All materials are provided in a format that is conductive to classroom presentation and discussion.

Keywords: binary number system, Nim game, telegraphy, computers prefer the ternary system

Procedia PDF Downloads 148
1049 Press Hardening of Tubes with Additional Interior Spray Cooling

Authors: B. A. Behrens, H. J. Maier, A. Neumann, J. Moritz, S. Hübner, T. Gretzki, F. Nürnberger, A. Spiekermeier

Abstract:

Press-hardened profiles are used e.g. for automotive applications in order to improve light weight construction due to the high reachable strength. The application of interior water-air spray cooling contributes to significantly reducing the cycle time in the production of heat-treated tubes. This paper describes a new manufacturing method for producing press-hardened hollow profiles by means of an additional interior cooling based on a water-air spray. Furthermore, this paper provides the results of thorough investigations on the properties of press-hardened tubes in dependence of varying spray parameters.

Keywords: 22MnB5, press hardening, water-air spray cooling, hollow profiles, tubes

Procedia PDF Downloads 245
1048 Comparative Studies on Thin Film of ZnO Deposited by Spray Pyrolysis and Sputtering Technique

Authors: Musa Momoh, A. U. Moreh, A. M. Bayawa, Sanusi Abdullahi, I. Atiku

Abstract:

In this study, thin films of ZnO were synthesized by two techniques namely RF sputtering and spray pyrolysis. The films were deposited on corning glass. The primary materials used are 99.99% pure. The optical and structural properties of the samples were studied. It has been noted that the samples deposited by Spray pyrolysis have and average transmittance, refractive index and extinction coefficient as 80-90%, 1.33-1.44 and 13.11-27.52 respectively. Those deposited by sputtering method are 34-80%, 1.51-1.52 and 3.15-3.28. The XRD patterns of the samples show that they are polycrystalline.

Keywords: zinc oxide, spray pyrolysis, rf sputtering, optical properties, electrical properties

Procedia PDF Downloads 228
1047 Hit-Or-Miss Transform as a Tool for Similar Shape Detection

Authors: Osama Mohamed Elrajubi, Idris El-Feghi, Mohamed Abu Baker Saghayer

Abstract:

This paper describes an identification of specific shapes within binary images using the morphological Hit-or-Miss Transform (HMT). Hit-or-Miss transform is a general binary morphological operation that can be used in searching of particular patterns of foreground and background pixels in an image. It is actually a basic operation of binary morphology since almost all other binary morphological operators are derived from it. The input of this method is a binary image and a structuring element (a template which will be searched in a binary image) while the output is another binary image. In this paper a modification of Hit-or-Miss transform has been proposed. The accuracy of algorithm is adjusted according to the similarity of the template and the sought template. The implementation of this method has been done by C language. The algorithm has been tested on several images and the results have shown that this new method can be used for similar shape detection.

Keywords: hit-or-miss operator transform, HMT, binary morphological operation, shape detection, binary images processing

Procedia PDF Downloads 293
1046 Colour Formation and Maillard Reactions in Spray-Dried Milk Powders

Authors: Zelin Zhou, Timothy Langrish

Abstract:

Spray drying is the final stage of milk powder production. Traditionally, the quality of spray-dried milk powders has mainly been assessed using their physical properties, such as their moisture contents, while chemical changes occurring during the spray drying process have often been ignored. With growing concerns about food quality, it is necessary to establish a better understanding of heat-induced degradation due to the spray-drying process of skim milk. In this study, the extent of thermal degradation for skim milk in a pilot-scale spray dryer has been investigated using different inlet gas temperatures. The extent of heat-induced damage has been measured by the formation of advanced Maillard reaction products and the loss of soluble proteins at pH 4.6 as assessed by a fluorometric method. A significant increase in the extent of thermal degradation has been found when the inlet gas temperature increased from 170°C to 190°C, suggesting protein unfolding may play an important role in the kinetics of heat-induced degradation for milk in spray dryers. Colour changes of the spray-dried skim milk powders have also been analysed using a standard lighting box. Colourimetric analysis results were expressed in CIELAB colour space with the use of the E index (E) and the Chroma (C) for measuring the difference between colours and the intensity of the colours. A strong linear correlation between the colour intensity of the spray-dried skim milk powders and the formation of advanced Maillard reaction products has been observed.

Keywords: colour formation, Maillard reactions, spray drying, skim milk powder

Procedia PDF Downloads 146
1045 Effect of Temperature and Feed Solution on Microencapsulation of Quercetin by Spray Drying Technique

Authors: S. Lekhavat, U. Srimongkoluk, P. Ratanachamnong, G. Laungsopapun

Abstract:

Quercetin was encapsulated with whey protein and high methoxyl pectin by spray drying technique. Feed solution, consisting of 0.1875 0.125 and 0.0625 % w/w quercetin, respectively, was prepared and then sprays at outlet temperature of 70, 80 and 90 °C. Quercetin contents either in feed solution or in spray dried powder were determined by HPLC technique. Physicochemical properties such as viscosity and total soluble solid of feed solution as well as moisture content and water activity of spray dried powder were examined. Particle morphology was imaged using scanning electron microscope. The results showed that feed solution has total soluble solid and viscosity in range of 1.73-5.60 ºBrix and 2.58-8.15 cP, in that order. After spray drying, the moisture content and water activity value of powder are in range of 0.58-2.72 % and 0.18-0.31, respectively. Quercetin content in dried sample increased along with outlet drying temperature but decreased when total soluble solid increased. It was shown that particles are likely to shrivel when spray drying at high temperature. The suggested conditions for encapsulation of quercetin are feed solution with 0.0625 % (w/w) quercetin and spray drying at drying outlet temperature of 90°C.

Keywords: drying temperature, particle morphology, spray drying, quercetin

Procedia PDF Downloads 228
1044 Numerical Simulation and Analysis on Liquid Nitrogen Spray Heat Exchanger

Authors: Wenjing Ding, Weiwei Shan, Zijuan, Wang, Chao He

Abstract:

Liquid spray heat exchanger is the critical equipment of temperature regulating system by gaseous nitrogen which realizes the environment temperature in the range of -180 ℃~+180 ℃. Liquid nitrogen is atomized into smaller liquid drops through liquid nitrogen sprayer and then contacts with gaseous nitrogen to be cooled. By adjusting the pressure of liquid nitrogen and gaseous nitrogen, the flowrate of liquid nitrogen is changed to realize the required outlet temperature of heat exchanger. The temperature accuracy of shrouds is ±1 ℃. Liquid nitrogen spray heat exchanger is simulated by CATIA, and the numerical simulation is performed by FLUENT. The comparison between the tests and numerical simulation is conducted. Moreover, the results help to improve the design of liquid nitrogen spray heat exchanger.

Keywords: liquid nitrogen spray, temperature regulating system, heat exchanger, numerical simulation

Procedia PDF Downloads 288
1043 The Physics of Cold Spray Technology

Authors: Ionel Botef

Abstract:

Studies show that, for qualitative coatings, the knowledge of cold spray technology must focus on a variety of interdisciplinary fields and a framework for problem solving. The integrated disciplines include, but are not limited to, engineering, material sciences, and physics. Due to its importance, the purpose of this paper is to summarize the state of the art of this technology alongside its theoretical and experimental studies, and explore the role and impact of physics upon cold spraying technology.

Keywords: surface engineering, cold spray, physics, modelling

Procedia PDF Downloads 502
1042 Minimizing Total Completion Time in No-Wait Flowshops with Setup Times

Authors: Ali Allahverdi

Abstract:

The m-machine no-wait flowshop scheduling problem is addressed in this paper. The objective is to minimize total completion time subject to the constraint that the makespan value is not greater than a certain value. Setup times are treated as separate from processing times. Several recent algorithms are adapted and proposed for the problem. An extensive computational analysis has been conducted for the evaluation of the proposed algorithms. The computational analysis indicates that the best proposed algorithm performs significantly better than the earlier existing best algorithm.

Keywords: scheduling, no-wait flowshop, algorithm, setup times, total completion time, makespan

Procedia PDF Downloads 316
1041 Tribological Behavior of Warm Rolled Spray Formed Al-6Si-1Mg-1Graphite Composite

Authors: Surendra Kumar Chourasiya, Sandeep Kumar, Devendra Singh

Abstract:

In the present investigation tribological behavior of Al-6Si-1Mg-1Graphite composite has been explained. The composite was developed through the unique spray forming route in the spray forming chamber by using N₂ gas at 7kg/cm² and the flight distance was 400 mm. Spray formed composite having a certain amount of porosity which was reduced by the deformations. The composite was subjected to the warm rolling (WR) at 250ºC up to 40% reduction. Spray forming composite shows the considerable microstructure refinement, equiaxed grains, distribution of silicon and graphite particles in the primary matrix of the composite. Graphite (Gr) was incorporated externally during the process that works as a solid lubricant. Porosity decreased after reduction and hardness increases. Pin on disc test has been performed to analyze the wear behavior which is the function of sliding distance for all percent reduction of the composite. 30% WR composite shows the better result of wear rate and coefficient of friction. The improved wear properties of the composite containing Gr are discussed in light of the microstructural features of spray formed the composite and the nature of the debris particles. Scanning electron microscope and optical microscope analysis of the present material supported the prediction of aforementioned changes.

Keywords: Al-6Si-1Mg-1Graphite, spray forming, warm rolling, wear

Procedia PDF Downloads 529
1040 On the Construction of Some Optimal Binary Linear Codes

Authors: Skezeer John B. Paz, Ederlina G. Nocon

Abstract:

Finding an optimal binary linear code is a central problem in coding theory. A binary linear code C = [n, k, d] is called optimal if there is no linear code with higher minimum distance d given the length n and the dimension k. There are bounds giving limits for the minimum distance d of a linear code of fixed length n and dimension k. The lower bound which can be taken by construction process tells that there is a known linear code having this minimum distance. The upper bound is given by theoretic results such as Griesmer bound. One way to find an optimal binary linear code is to make the lower bound of d equal to its higher bound. That is, to construct a binary linear code which achieves the highest possible value of its minimum distance d, given n and k. Some optimal binary linear codes were presented by Andries Brouwer in his published table on bounds of the minimum distance d of binary linear codes for 1 ≤ n ≤ 256 and k ≤ n. This was further improved by Markus Grassl by giving a detailed construction process for each code exhibiting the lower bound. In this paper, we construct new optimal binary linear codes by using some construction processes on existing binary linear codes. Particularly, we developed an algorithm applied to the codes already constructed to extend the list of optimal binary linear codes up to 257 ≤ n ≤ 300 for k ≤ 7.

Keywords: bounds of linear codes, Griesmer bound, construction of linear codes, optimal binary linear codes

Procedia PDF Downloads 714
1039 Technology of Thermal Spray Coating Machining

Authors: Jana Petrů, Tomáš Zlámal, Robert Čep, Lenka Čepová

Abstract:

This article is focused on the thermal spray coating machining issue. Those are irreplaceable in many areas of nowadays industrial branches such as aerospace industry, mostly thanks to their excellent qualities in production and also in renovation of machinery parts. The principals of thermal spraying and elementary diversification are described in introduction. Plasma coating method of composite materials -cermets- is described more thoroughly. The second part describes thermal spray coating machining and grinding in detail. This part contains suggestion of appropriate grinding tool and assessment of cutting conditions used for grinding a given part. Conclusion describes a problem which occurred while grinding a cermet thermal spray coating with a specially designed grindstone and a way to solve this problem.

Keywords: coating, aerospace, plasma, grinding

Procedia PDF Downloads 516
1038 The Effect of Water Droplets Size in Fire Fighting Systems

Authors: Tassadit Tabouche

Abstract:

Water sprays pattern, and water droplets size (different droplets diameter) are a key factors in the success of the suppression by water spray. The effects of the two important factors are investigated in this study. However, the fire extinguishing mechanism in such devices is not well understood due to the complexity of the physical and chemical interactions between water spray and fire plume. in this study, 3D, unsteady, two phase flow CFD simulation approach is introduced to provide a quantitative analysis of the complex interactions occurring between water spray and fire plume. Lagrangian Discrete Phase Model (DPM) was used for water droplets and a global one-step reaction mechanism in combustion model was used for fire plume.

Keywords: droplets, water spray, water droplets size, 3D

Procedia PDF Downloads 493
1037 Granule Morphology of Zirconia Powder with Solid Content on Two-Fluid Spray Drying

Authors: Hyeongdo Jeong, Jong Kook Lee

Abstract:

Granule morphology and microstructure were affected by slurry viscosity, chemical composition, particle size and spray drying process. In this study, we investigated granule morphology of zirconia powder with solid content on two-fluid spray drying. Zirconia granules after spray drying show sphere-like shapes with a diameter of 40-70 μm at low solid contents (30 or 40 wt%) and specific surface area of 5.1-5.6 m²/g. But a donut-like shape with a few cracks were observed on zirconia granules prepared from the slurry of high solid content (50 wt %), green compacts after cold isostatic pressing under the pressure of 200 MPa have the density of 2.1-2.2 g/cm³ and homogeneous fracture surface by complete destruction of granules. After the sintering at 1500 °C for 2 h, all specimens have relative density of 96.2-98.3 %. With increasing a solid content from 30 to 50 wt%, grain size increased from 0.3 to 0.6 μm, but relative density was inversely decreased from 98.3 to 96.2 %.

Keywords: zirconia, solid content, granulation, spray drying

Procedia PDF Downloads 182
1036 Preparation of Amla (Phyllanthus emblica) Powder Using Spray Drying Technique

Authors: Shubham Mandliya, Pooja Pandey, H. N. Mishra

Abstract:

Amla (Phyllanthus emblica), a plant of Euphorbiaceous is widely distributed in subtropical and tropical areas of China, India, Indonesia, and Malaysia. Amla is very high in vitamin C content. Spray drying of fruit juices represents another alternative way to improve the physicochemical stability and increase their shelf life. Samples of amla powder were produced using the spray drying method to investigate the effect of inlet temperatures and maltodextrin levels. The spray dryer model used was a laboratory scale dryer and samples were run at different temperatures and concentrations. The response surface methodology (RSM) was used to optimize the spray-drying process for the development of amla powder. The resultant powders were then analyzed for vitamin C, moisture, solubility and dispersibility. The spray dried amla powder contains higher amounts of vitamin C when compared to commercial fruit juice powders. SEM analysis revealed that lower maltodextrin levels and higher inlet air temperatures resulted in smaller but smoother particles. At lower temperature, vitamin C content is high as compared to higher temperature. Spray drying is an effective as well as an economic method which can be commercially used for making powder rather than by tray or solar drying as more fraction is retained with less cost.

Keywords: Amla powder, physiochemical properties, response surface methodology, spray drying

Procedia PDF Downloads 201
1035 Effect of Drop Impact Behavior on Spray Retention

Authors: Hassina Hafida Boukhalfa, Mathieu Massinon, Fréderic Lebeau, Mohamed Belhamra

Abstract:

Drop behaviour during impact affects retention. The increase of adhesion is usually seen as the objective when applying crop protection products, while bouncing and shattering are seen as detrimental to spray retention. However, observation of drop impacts using high speed shadow graphy shows that fragmentation can occur in Wenzel wetting regime. In this case, a part of the drop sticks on the surface, what contributes to retention. Using simultaneous measurements of drop impacts with high speed imaging and of retention with fluorometry for 3 spray mixtures on excised barley leaves allowed us to observe that about 50% of the drops fragmented in Wenzel state remain on the leaf. Depending on spray mixture, these impact outcomes accounted for 25 to 50% of retention, the higher contribution being correlated with bigger VMD (Volume Median Diameter). This contribution is non-negligible and should be considered when a modelling of spray retention process is performed.

Keywords: drop impact, retention, fluorometry, high speed imaging

Procedia PDF Downloads 349
1034 Soret-Driven Convection in a Binary Fluid with Coriolis Force

Authors: N. H. Z. Abidin, N. F. M. Mokhtar, S. S. A. Gani

Abstract:

The influence of diffusion of the thermal or known as Soret effect in a heated Binary fluid model with Coriolis force is investigated theoretically. The linear stability analysis is used, and the eigenvalue is obtained using the Galerkin method. The impact of the Soret and Coriolis force on the onset of stationary convection in a system is analysed with respect to various Binary fluid parameters and presented graphically. It is found that an increase of the Soret values, destabilize the Binary fluid layer system. However, elevating the values of the Coriolis force helps to lag the onset of convection in a system.

Keywords: Benard convection, binary fluid, Coriolis, Soret

Procedia PDF Downloads 349
1033 Modeling and Simulating Drop Interactions in Spray Structure of High Torque Low Speed Diesel Engine

Authors: Rizwan Latif, Syed Adnan Qasim, Muzaffar Ali

Abstract:

Fuel direct injection represents one of the key aspects in the development of the diesel engines, the idea of controlling the auto-ignition and the consequent combustion of a liquid spray injected in a reacting atmosphere during a time scale of few milliseconds has been a challenging task for the engine community and pushed forward to a massive research in this field. The quality of the air-fuel mixture defines the combustion efficiency, and therefore the engine efficiency. A droplet interaction in dense as well as thin portion of the spray receives equal importance as other parameters in spray structure. Usually, these are modeled along with breakup process and analyzed alike. In this paper, droplet interaction is modeled and simulated for high torque low speed scenario. Droplet interactions may further be subdivided into droplet collision and coalescence, spray wall impingement, droplets drag, etc. Droplet collisions may occur in almost all spray applications, but especially in diesel like conditions such as high pressure sprays as utilized in combustion engines. These collisions have a strong influence on the mean droplet size and its spatial distribution and can, therefore, affect sub-processes of spray combustion such as mass, momentum and energy transfer between gas and droplets. Similarly, for high-pressure injection systems spray wall impingement is an inherent sub-process of mixture formation. However, its influence on combustion is in-explicit.

Keywords: droplet collision, coalescence, low speed, diesel fuel

Procedia PDF Downloads 212
1032 Diesel Engine Performance Optimization to Reduce Fuel Consumption and Emissions Issues

Authors: hadi kargar, bahador shabani

Abstract:

In this article, 16 cylinder motor combustion CFD modeling with a diameter of 165 mm and 195 mm along the way to help the FIRE software to optimize its function to work. A three-dimensional model of the processes that formed inside the cylinder made that involves mixing the fuel and air, ignition and spraying. In this three-dimensional model, all chemical species, density of air fuel spraying and spray with full profile intended to detailed results from mixing the fuel and air, igniting the ignition advance, spray, and mixed media in different times and get fit by moving the piston. Optimal selection of the model for the shape of the piston and spraying fuel specifications (including the management of spraying, the number of azhneh hole, start time of spraying and spraying angle) to achieve the best fuel consumption and minimal pollution. The spray hole 6 and 7 in three different configurations with five spraying and gives the best geometry and various performances in the simulation. 6 hole spray angle, finally spraying 72.5 degrees and two forms of spraying a better performance in comparison with other items of their own.

Keywords: spray, FIRE, CFD, optimize, diesel engine

Procedia PDF Downloads 386
1031 Survival of Four Probiotic Strains in Acid, Bile Salt and After Spray Drying

Authors: Rawichar Chaipojjana, Suttipong Phosuksirikul, Arunsri Leejeerajumnean

Abstract:

The objective of the study was to select the survival of probiotic strains when exposed to acidic and bile salts condition. Four probiotic strains (Lactobacillus casei subsp. rhamnosus TISTR 047, Lactobacillus casei TISTR 1500, Lactobacillus acidophilus TISTR 1338 and Lactobacillus plantarum TISTR 1465) were cultured in MRS broth and incubated at 35ºC for 15 hours before being inoculated into acidic condition (5 M HCl, pH 2) for 2 hours and bile salt (0.3%, pH 5.8) for 8 hour. The survived probiotics were counted in MRS agar. Among four stains, Lactobacillus casei subsp. rhamnosus TISTR 047 was the highest tolerance specie. Lactobacillus casei subsp. rhamnosus TISTR 047 reduced 6.74±0.07 log CFU/ml after growing in acid and 5.52±0.05 log CFU/ml after growing in bile salt. Then, double emulsion of microorganisms was chosen to encapsulate before spray drying. Spray drying was done with the inlet temperature 170ºC and outlet temperature 80ºC. The results showed that the survival of encapsulated Lactobacillus casei subsp. rhamnosus TISTR 047 after spray drying decreased from 9.63 ± 0.32 to 8.31 ± 0.11 log CFU/ml comparing with non-encapsulated, 9.63 ± 0.32 to 4.06 ± 0.08 log CFU/ml. Therefore, Lactobacillus casei subsp. rhamnosus TISTR 047 would be able to survive in gastrointestinal and spray drying condition.

Keywords: probiotic, acid, bile salt, spray drying

Procedia PDF Downloads 331
1030 Numerical Simulation of Liquid Nitrogen Spray Equipment for Space Environmental Simulation Facility

Authors: He Chao, Zhang Lei, Liu Ran, Li Ang

Abstract:

Temperature regulating system by gaseous nitrogen is of importance to the space environment simulator, which keep the shrouds in the temperature range from -150℃ to +150℃. Liquid nitrogen spray equipment is one of the most critical parts in the temperature regulating system by gaseous nitrogen. Y type jet atomizer and internal mixing atomizer of the liquid nitrogen spray equipment are studied in this paper, 2D/3D atomizer model was established and grid division was conducted respectively by the software of Catia and ICEM. Based on the above preparation, numerical simulation on the spraying process of the atomizer by FLUENT is performed. Using air and water as the medium, comparison between the tests and numerical simulation was conducted and the results of two ways match well. Hence, it can be conclude that this atomizer model can be applied in the numerical simulation of liquid nitrogen spray equipment.

Keywords: space environmental simulator, liquid nitrogen spray, Y type jet atomizer, internal mixing atomizer, numerical simulation, fluent

Procedia PDF Downloads 375
1029 Reconstruction of Binary Matrices Satisfying Neighborhood Constraints by Simulated Annealing

Authors: Divyesh Patel, Tanuja Srivastava

Abstract:

This paper considers the NP-hard problem of reconstructing binary matrices satisfying exactly-1-4-adjacency constraint from its row and column projections. This problem is formulated into a maximization problem. The objective function gives a measure of adjacency constraint for the binary matrices. The maximization problem is solved by the simulated annealing algorithm and experimental results are presented.

Keywords: discrete tomography, exactly-1-4-adjacency, simulated annealing, binary matrices

Procedia PDF Downloads 373
1028 Solving Flowshop Scheduling Problems with Ant Colony Optimization Heuristic

Authors: Arshad Mehmood Ch, Riaz Ahmad, Imran Ali Ch, Waqas Durrani

Abstract:

This study deals with the application of Ant Colony Optimization (ACO) approach to solve no-wait flowshop scheduling problem (NW-FSSP). ACO algorithm so developed has been coded on Matlab computer application. The paper covers detailed steps to apply ACO and focuses on judging the strength of ACO in relation to other solution techniques previously applied to solve no-wait flowshop problem. The general purpose approach was able to find reasonably accurate solutions for almost all the problems under consideration and was able to handle a fairly large spectrum of problems with far reduced CPU effort. Careful scrutiny of the results reveals that the algorithm presented results better than other approaches like Genetic algorithm and Tabu Search heuristics etc; earlier applied to solve NW-FSSP data sets.

Keywords: no-wait, flowshop, scheduling, ant colony optimization (ACO), makespan

Procedia PDF Downloads 400