Computational Fluid Dynamics Analysis for Flow Field of Radiator Air Intake in the Powertrain Compartment

2013 ◽  
Vol 464 ◽  
pp. 171-175
Author(s):  
Lin Lin Song ◽  
Wei Zheng Zhang ◽  
Yuan Fu Cao ◽  
Ya Lei Zeng

A computational fluid dynamics (CFD) model of tank powertrain compartment was constructed for cooling air flow and heat transfer analysis. The key points temperatures of the powertrain compartment were tested, and the numerical values have a good agreement with the measurement datas. Detailed cooling air flow field distributing characteristic through radiators in the powertrain compartment were obtained through numerical method, with different fan speeds and ambient wind speeds. These results can provide the basis for the choice of the fan speed on specific condition and the air flow distribution of the radiator.

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Yingying Xu ◽  
Libin Tan ◽  
Yuejin Yuan ◽  
Man Zhang

Achieving an optimal cooling of the generator unit is indispensable for high working performance. In this work, computational fluid dynamics analysis on the flow field of the conventional type and silent type of the S688CCS series generator unit is conducted, and design optimization of the generator unit with poor cooling is studied based on flow field analysis results. Flow field simulation results indicate that the total cooling air quantity of the silent type generator unit is lower than that of the conventional type generator unit, and the cooling air quantity of the radiator is also lower than that of the conventional type generator unit, which is not conductive for the cooling of the silent type generator unit. The flow field optimization is achieved by adopting the single variable control method to improve the structure of the fan cover, silent components for silence, adjacent structure, and air inlet grille. The corresponding structure optimization scheme is put forward. After optimization, the air quantity for the cooling radiator of the silent type generator unit is 44.33% higher than that of its original structure, and the total cooling air quantity is higher than that of the conventional type generator unit. The research results in this work can provide a theoretical basis for the design of the cooling air flow path of generator units for achieving an optimal cooling performance.


2013 ◽  
Vol 368-370 ◽  
pp. 619-623
Author(s):  
Zhen Liu ◽  
Xiao Ling Wang ◽  
Ai Li Zhang

For the purpose of avoiding the deficiency of the traditional construction ventilation, the ventilation of the underground main powerhouse is simulated by the computational fluid dynamics (CFD) to optimize ventilation parameters. A 3D unsteady RNG k-ε model is performed for construction ventilation in the underground main powerhouse. The air-flow field and CO diffusion in the main powerhouse are simulated and analyzed. The two construction ventilation schemes are modelled for the main powerhouse. The optimized ventilation scheme is obtained by comparing the air volume and pressure distributions of the different ventilation schemes.


Author(s):  
Jesper Lebæk ◽  
Marcin Blazniak Andreasen ◽  
Henrik Assenholm Andresen ◽  
Mads Bang ◽  
Søren Knudsen Kær

The inlet effect on the manifold flow in a fuel cell stack was investigated by means of numerical methods (computational fluid dynamics) and experimental methods (particle image velocimetry). At a simulated high current density situation the flow field was mapped on a 70 cell simulated cathode manifold. Three different inlet configurations were tested: plug flow, circular inlet, and a diffuser inlet. A very distinct jet was formed in the manifold, when using the circular inlet configuration, which was confirmed both experimentally and numerically. This jet was found to be an asymmetric confined jet, known as the symmetry-breaking bifurcation phenomenon, and it is believed to cause a significant maldistribution of the stack flow distribution. The investigated diffuser design proved to generate a much smoother transition from the pipe flow to the manifold flow with a subsequent better flow distribution. A method was found in the literature to probe if there is a risk of jet asymmetry; it is however recommended by the author to implement a diffuser design, as this will generate better stack flow distribution and less head loss. Generally, the numerical and experimental results were found in to be good agreement, however, a detailed investigation revealed some difference in the results.


2014 ◽  
Vol 18 (4) ◽  
pp. 1191-1201 ◽  
Author(s):  
Nader Pourmahmoud ◽  
Alireza Izadi ◽  
Amir Hassanzadeh ◽  
Ashkan Jahangiramini

In this article computational fluid dynamics analysis of a three-dimensional compressible and turbulent flow has been carried out through a vortex tube. The standard k-? turbulence model is utilized in order to simulate an axisymmetric computational domain. The numerical simulation has focused on the energy separation and flow field patterns of a somewhat nonconventional vortex tube, which is on the basis of creating an external hole at the end of each nozzle. According to the selected nozzles geometry, some of unfavorable phenomena such as shock wave, high pressure regions and appearing of unsymmetrical rotating flow patterns in the vortex chamber would be recovered significantly. In this way the physical parameters of flow field are derived under different both inlet mass flow rates and outlet pressures of nozzles hole (OPH). The results show that increasing OPH value enhanced the cooling capacity of machine in the most of operating conditions.


2014 ◽  
Author(s):  
Leonardo Fonseca ◽  
Raphael Meireles ◽  
Rudolf Huebner ◽  
Matheus Carvalho ◽  
Ramon Molina

2019 ◽  
Vol 9 (4) ◽  
pp. 4452-4456
Author(s):  
W. F. Lima ◽  
R. Huebner

Baghouse filters are used to reduce the emission of pollutants in the atmosphere. With the stricter environmental regulations and the need to avoid the emission of pollutants into the atmosphere, the demand for better results in terms of collection efficiency and filtration rises. A good performance of a baghouse filter is closely linked to the correct flow distribution inside it, whether in the hopper or in the bags. Other important variables for good performance are internal speed, filtration rate (RAP), pressure drop, cleaning efficiency, etc. The upgrading of existing bag filters to current standards is a major challenge for the industry, generally due to, among other factors, emission regulations and common physical and dimensional constraints of the existing equipment. Computational Fluid Dynamics analysis (CFD) can help deal with this problem because it makes possible to perform several analyzes at a lower cost and with great result accuracy when compared with the traditional approaches. In this work, the analysis of an existing bag filter, which presents serious problems of premature discharging of components due to nonuniformity in the internal distribution of the flow, is performed. This analysis has several steps, among them, documentation survey, field survey, flow and pressure drop measurements (pressure differential between the clean side and the dirty side of the filter) with the aid of CFD, with the objective to raise pressure and velocity and to identify possible dimensional changes to improve flow uniformity.


PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0250837
Author(s):  
Keisuke Doi ◽  
Tsutomu Takagi ◽  
Yasushi Mitsunaga ◽  
Shinsuke Torisawa

Fish form schools because of many possible reasons. However, the hydrodynamic mechanism whereby the energy efficiency of fish schools is improved still remains unclear. There are limited examples of fish models based on actual swimming movements using simulation, and the movements in existing models are simple. Therefore, in this study, we analyzed the swimming behavior of Biwa salmon (Oncorhynchus sp., a salmonid fish) using image analyses and formulated its swimming motion. Moreover, computational fluid dynamics analysis was carried out using the formulated swimming motion to determine the fluid force acting on the fish body model with real fish swimming motion. The swimming efficiency of the fish model under parallel swimming was obtained from the calculated surrounding fluid force and compared for different neighboring distances. The flow field around the fish model was also examined. The swimming efficiency of two fish models swimming parallelly was improved by approximately 10% when they were separated by a distance of 0.4L, where L is the total length of the model. In addition, the flow field behind the fish body was examined under both inphase and antiphase conditions and at inter-individual distances of 0.8L and 1.2L. The apparent flow speed in the distance range of 0.5–2.0L from the midpoint of the snouts of the two individuals was lower than the swimming speed. The pressure distribution on the fish model showed an elevated pressure at the caudal fin. Interestingly, we obtained an isopleth map similar to that of a caudal peduncle. To avoid a negative thrust, the aft part of the body must be thin, as shown in the isopleth map obtained in this study.


Author(s):  
Damian E. Ramajo ◽  
Norberto M. Nigro

Numerical and experimental techniques were applied in order to study the in-cylinder flow field in a commercial four-valve per cylinder spark ignition engine. Investigation was aimed at analyzing the generation and evolution of tumble-vortex structures during the intake and compression strokes, and the capacity of this engine to promote turbulence enhancement during tumble degradation at the end of the compression stroke. For these purposes, three different approaches were analyzed. First, steady flow rig tests were experimentally carried out, and then reproduced by computational fluid dynamics (CFD). Once CFD was assessed, cold dynamic simulations of the full engine cycle were performed for several engine speeds (1500 rpm, 3000 rpm, and 4500 rpm). Steady and cold dynamic results were compared in order to assess the feasibility of the former to quantify the in-cylinder flow. After that, combustion was incorporated by means of a homogeneous heat source, and dynamic boundary conditions were introduced in order to approach real engine conditions. The combustion model estimates the burning rate as a function of some averaged in-cylinder flow variables (temperature, pressure, turbulent intensity, and piston position). Results were employed to characterize the in-cylinder flow field of the engine and to establish similarities and differences between the three performed tests that are currently used to estimate the engine mean flow characteristics (steady flow rig, and cold and real dynamic simulations).


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