Effects of vortexes in feed header on air flow distribution of PEMFC stack: CFD simulation and optimization for better uniformity

2021 ◽  
Vol 173 ◽  
pp. 498-506
Author(s):  
Guoqing Su ◽  
Daijun Yang ◽  
Qiangfeng Xiao ◽  
Haiqin Dai ◽  
Cunman Zhang
2008 ◽  
Vol 13 (1) ◽  
pp. 89-101 ◽  
Author(s):  
M. M. A. Sarker ◽  
E. Kim ◽  
G. C. Moon ◽  
J. I. Yoon

The performance characteristics of the Hybrid Closed Circuit Cooling Tower (HCCCT) have been investigated applying computational fluid dynamics (CFD). Widely reported CFD techniques are applied to simulate the air-water two phase flow inside the HCCCT. The pressure drop and the cooling capacity were investigated from several perspectives. Three different transverse pitches were tested and found that a pitch of 45 mm had lower pressure drop. The CFD simulation indicated that when air is supplied from the side wall of the HCCCT, the pressure drop can be over predicted and the cooling capacity can be under predicted mainly due to the non-uniform air flow distribution across the coil bank. The cooling capacity in wet mode have been calculated with respect to wet-bulb temperature (WBT) and cooling water to air mass flow rates for different spray water volume flow rates and the results were compared to the experimental measurement and found to conform well for the air supply from the bottom end. The differences of the cooling capacity and pressure drop in between the CFD simulation and experimental measurement in hybrid mode were less than 5 % and 7 % respectively for the uniform air flow distribution.


2012 ◽  
Vol 443-444 ◽  
pp. 1007-1013
Author(s):  
Hong Jiang Cui ◽  
Ming Hai Li ◽  
Ying Guan

.In order to manufacture high quality intake port with bigger discharge coefficient and appropriate swirl ratio for diesel engine performance improvement, intake port tests and CFD simulation method were combined together to optimize its structure. The three-dimensional CAD model of intake port was built and was putted into AVL–FIRE platform to do CFD simulation with appropriate turbulence model and calculation method. The detailed air flow information was obtained by CFD simulation. After analyzing, two optimization programs were discussed. This research shows that CFD simulation is a powerful method to design diesel engine intake port; air flow condition is complex in the intake port; intake port structure optimization can increase the discharge coefficient and improve the air flow condition.


Author(s):  
Mohd Afzanizam Mohd Rosli ◽  
◽  
Hiew Sit Jing ◽  
Nur Izzati Mohd Azhar ◽  
Maidi Saputra ◽  
...  

Drying chamber is a drying application for agriculture product to produce high quality and hygiene product. The purpose of this paper is to propose best configuration trays arrangement in drying chamber for better distribution of velocity and temperature. Therefore, five configurations of trays are analyzed to obtain the best performance of uniformity air flow distribution within drying chamber. CFD simulation studied the uniform air flow in the drying chamber in steady state condition. A validation is performed by comparing the data obtained from the literature review CFD simulation to ensure the methodology is correct. Then, the drying chamber with different trays arrangements are simulated using CFD simulations to obtain velocity and temperature distributions at nine plotted points on trays. From the results obtained, it concluded that design (A) and (D) are selected as the best designs for uniformity because there is less discrepancy for each point contributed the more uniformity of distribution.


2012 ◽  
Vol 614-615 ◽  
pp. 701-706
Author(s):  
Chao Huang ◽  
Fang Wang ◽  
Zhi Min Wu ◽  
Chao Guo

Based on European Standard EN441-2, an experiment system for measuring the thermal properties of refrigerated display cabinet is designed and constructed. Considering the practice requirements from user, the air distribution analysis is doing under various air-flow form in the testing room. This paper uses the FLUENT, which is one of the CFD simulation software, to verify the design method of air movement. Finally a series of tests required for laboratory quality regulation have been done and the data of velocity or temperature is under the new requirement.


2015 ◽  
Vol 735 ◽  
pp. 85-90
Author(s):  
Noor Emilia Ahmad Shafie ◽  
Haslinda Mohamed Kamar ◽  
Nazri Kamsah

Good ventilation is important for passenger for sufficient supply of fresh air during commuting in a bus. Insufficient fresh air causes feeling of uncomfortable to passenger and affects passenger’s health. Airborne transmission disease, headache and respiratory allergies are the usual health symptoms. This paper presents the CFD study of air flow inside a bus passenger compartment. The objective is to estimate the temperature level at the diffuser, seat and floor locations of the bus passenger compartment. Two conditions of airflow velocity at the supply diffuser were examined, namely 2.7 m/s and 3.1 m/s. A CFD Fluent software was employed to develop and meshed a simplified 3D model of a quarter section of a bus passenger compartment. Air velocity and temperature boundary conditions were prescribed on the model based on the actual data obtained from field measurement. Turbulent flow analyses were carried out using standard k-ε model to visualize the air flow distribution inside the compartment. The results show that the velocity distribution is uniform when the diffuser air velocity is 3.1 m/s. When the diffuser air velocity is 3.1 m/s the air temperature of the seat area was decreased by 0.3°C. The air temperature inside the cabin can be maintained uniform at 23°C when diffuser air velocity was fixed at 3.1 m/s.


2016 ◽  
Vol 69 (7) ◽  
pp. 710-726 ◽  
Author(s):  
U. Pasquier ◽  
W. X. Chu ◽  
M. Zeng ◽  
Y. T. Chen ◽  
Q. W. Wang ◽  
...  

Designs ◽  
2021 ◽  
Vol 5 (1) ◽  
pp. 4
Author(s):  
Dillon Alexander Wilson ◽  
Kul Pun ◽  
Poo Balan Ganesan ◽  
Faik Hamad

Microbubble generators are of considerable importance to a range of scientific fields from use in aquaculture and engineering to medical applications. This is due to the fact the amount of sea life in the water is proportional to the amount of oxygen in it. In this paper, experimental measurements and computational Fluid Dynamics (CFD) simulation are performed for three water flow rates and three with three different air flow rates. The experimental data presented in the paper are used to validate the CFD model. Then, the CFD model is used to study the effect of diverging angle and throat length/throat diameter ratio on the size of the microbubble produced by the Venturi-type microbubble generator. The experimental results showed that increasing water flow rate and reducing the air flow rate produces smaller microbubbles. The prediction from the CFD results indicated that throat length/throat diameter ratio and diffuser divergent angle have a small effect on bubble diameter distribution and average bubble diameter for the range of the throat water velocities used in this study.


Author(s):  
Fabio De Bellis ◽  
Luciano A. Catalano ◽  
Andrea Dadone

The numerical simulation of horizontal axis wind turbines (HAWT) has been analysed using computational fluid dynamics (CFD) with the aim of obtaining reliable but at the same time affordable wind turbine simulations, while significantly reducing required overall resources (time, computational power, user skills), for example in an optimization perspective. Starting from mesh generation, time required to extract preliminary aerodynamic predictions of a wind turbine blade has been shortened by means of some simplifications, i.e.: fully unstructured mesh topology, reduced grid size, incompressible flow assumption, use of wall functions, commercial available CFD package employment. Ansys Fluent software package has been employed to solve Reynolds Averaged Navier Stokes (RANS) equations, and results obtained have been compared against NREL Phase VI campaign data. The whole CFD process (pre-processing, processing, postprocessing) has been analysed and the chosen final settings are the result of a trade-off between numerical accuracy and required resources. Besides the introduced simplifications, numerical predictions of shaft torque, forces and flow distribution are in good agreement with experimental data and as accurate as those calcuted by other more sophisticated works.


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