scholarly journals Analysis of flow-field and heat exchange for a blunted cone at hypersonic speeds

2020 ◽  
Vol 1683 ◽  
pp. 022030
Author(s):  
S M Drozdov ◽  
A S Rtishcheva
Keyword(s):  
Heat Exchange ◽  
Flow Field ◽  
Hypersonic Speeds

scholarly journals Heat exchange performance optimization of a wheel loader cooling system based on computational fluid dynamic simulation

2018 ◽  
Vol 10 (11) ◽  
pp. 168781401880398 ◽  
Author(s):  
Chao Yu ◽  
Sicheng Qin ◽  
Yang Liu ◽  
Bosen Chai
Keyword(s):  
Heat Exchange ◽  
Flow Field ◽  
Thermal Management ◽  
Cooling System ◽  
Management Model ◽  
Maximum Deviation ◽  
Engine Compartment ◽  
Wheel Loader ◽  
Exchange Performance ◽  
Transmission Oil

This study establishes a thermal management model to improve the heat exchange performance and uniformity of the flow-field distribution in the engine compartment of a wheel loader. Flow-field analyses are performed for an XG956 wheel loader in a virtual wind tunnel using the combined engine compartment thermal management model and computational fluid dynamics. The Fluent calculations revealed various problems. For example, the inlet flow rate at both sides of the engine compartment is small, which accounts for about 8.5% of the total flow, and the flow uniformity of radiator becomes worse with the increase in the air flow. The original cooling system is improved based on the simulation results and then verified by field testing. A comparison of the test data with the simulations indicates that the values obtained using the thermal management model of the engine compartment are largely in agreement with the experimental values, with a maximum deviation of the heat transfer rate at the rated speed of 5.1%. The research method presented in this article could further help to increase the productivity of the non-road mobile machinery cooling system and lower design costs. The temperature of pressurized air, hydraulic oil, transmission oil, and engine cooling fluid decreased by 22.5%, 8.7%, 2.2%, and 8.4% in the improved loader, respectively.

Modeling for 3-D Temperature Field of Oil-Immersed Transformer

2011 ◽  
Vol 199-200 ◽  
pp. 1487-1491
Author(s):  
Su Xiang Qian ◽  
Ju Wu Xu ◽  
Xiao Jun Gu
Keyword(s):  
Temperature Field ◽  
Heat Exchange ◽  
Flow Field ◽  
Computer Experiment ◽  
Geometrical Model ◽  
Actual Situation ◽  
Traditional Methods ◽  
Ansys Cfx

The knowledge of temperature field of oil-filled transformer directly related to the judgment of overheated fault. There are mainly heat exchange, convection and their coupling in the transformer. Lot of traditional methods are not enough direct-viewing, and ignore the actual situation. The geometrical model of the transformer first modeled by Solidworks, and then ANSYS CFX is used to simulate the temperature field and flow field. Get a set of computer experiment result which can be reference. This computer experiment bring forth the method and effect of the simulate using that software, and make a foundation for the research of transformer overheated fault.

Research of Smoke Isolating with Air Curtain at Ship’s Tunnel

2012 ◽  
Vol 516-517 ◽  
pp. 111-114
Author(s):  
Xiao Jun Zhu ◽  
Chen Hua Zhong
Keyword(s):  
Heat Exchange ◽  
Flow Field ◽  
Air Curtain ◽  
Heat Control ◽  
The Way

The rapid spreading of poisonous smoke is the main reason which causes death in ship fires. Ships always have long tunnels to traveling passengers or cargos. Because of their longness and straightness, smoke diffuses rapidly. Fire doors are used to stop the smoke from spreading into other parts in vessels. When the fire doors are closed, the way for evacuation is also closed. So it’s important for the professionals to develop a kind of smoke-preventing device which can let people pass by when stopping the smoke. The air curtain is a kind of smoke isolating device which is used to decrease the heat exchange in supermarket or freezer. This paper analyzes flow field, the heat control and the smoke isolating ability of air curtain used in the ships’ long tunnels with different jet angles and initial velocities. At last, a suitable angle is proposed.

Design of Breathing Air-Condition Cabinet Based on Capillary Tube Combined with Heat Exchange and Dehumidification

2011 ◽  
Vol 71-78 ◽  
pp. 3415-3418
Author(s):  
Xiao Rui Liu ◽  
Bao Yu Li ◽  
Dong Tai Han ◽  
Xue Yong Lv
Keyword(s):  
Heat Exchanger ◽  
Heat Exchange ◽  
Flow Field ◽  
Energy Conservation ◽  
High Efficiency ◽  
Capillary Tube ◽  
Major Parameter ◽  
Depth Study ◽  
Moisture Condensation ◽  
The Moment

Capillary tube, a efficient and energy conservation heat exchanger, has been widely used abroad. In china, the research of air-condition terminal based on capillary tube is focus on the planar radiation at the moment. But kinds of problems such as moisture condensation happen because of the different climate of China. So we put forward developing a kind of breathing air-condition cabinet combined with heat exchange and dehumidification, and do some calculation about major parameter. We will do in-depth study on cabinet's flow field so that it can be high-efficiency.

Heat alleviation studies on hypersonic re-entry vehicles

2018 ◽  
Vol 122 (1257) ◽  
pp. 1673-1696 ◽  
Author(s):  
M. Khalid ◽  
K. A. Juhany
Keyword(s):  
Numerical Simulation ◽  
Boundary Condition ◽  
Flow Field ◽  
Hypersonic Flow ◽  
Flow Rate ◽  
Leading Edge ◽  
Control Surface ◽  
Solid Boundary ◽  
Simulation Techniques ◽  
Hypersonic Speeds

ABSTRACTA numerical simulation has been carried out to investigate the effects of leading edge blowing upon heat alleviation on the surface of hypersonic vehicles. The initial phase of this work deals with the ability of the present CFD-based techniques to solve hypersonic flow field past blunt-nosed vehicles at hypersonic speeds. Towards this end, the authors selected three re-entry vehicles with published flow field data against which the present computed results could be measured. With increasing confidence on the numerical simulation techniques to accurately resolve the hypersonic flow, the boundary condition at the solid blunt surface was then equipped with the ability to blow the flow out of the solid boundary at a rate of at least 0.01–0.1 times the free stream (ρ∞u∞) mass flow rate. The numerical iterative procedure was then progressed until the flow at the surface matched this new ‘inviscid like’ boundary condition. The actual matching of the flow field at the ejection control surface was achieved by iterating the flow on the adjacent cells until the flow conformed to the conditions prescribed at the control surface. The conditions at the surface could be submitted as a ρ∞u∞at the surface or could be equipped as a simple static pressure condition providing the desired flow rate. The comparison between the present engineering approach and the experimental data presented in this study demonstrate its ability to solve complex problems in hypersonic.

scholarly journals Effect of Micro-Vortex Generator in Hypersonic Inlet

2011 ◽  
pp. 10-13
Author(s):  
Vivek V. Kumar ◽  
Surendra Bogadi
Keyword(s):  
Boundary Layer ◽  
Flow Field ◽  
Vortex Generator ◽  
Adverse Pressure Gradient ◽  
Actual Case ◽  
Hypersonic Inlet ◽  
Hypersonic Speeds ◽  
Structured Meshes ◽  
Free Stream Mach Number ◽  
Micro Vortex Generator

In the present study computational tests were carried out to get an understanding of the flow field in a pure mixedcompression hypersonic inlet at a free stream Mach number of 7 and an altitude of 35km. Structured meshes have been used for depicting the motion of fluid inside the inlet. First, a grid has been selected after conducting a grid study. Two dimensional simulations were carried out with standard sst k-ω model using FLUENT. Computational results are compared with the available data. The results obtained from the computational tests revealed several important flow field details at hypersonic speeds. The basic shock structure inside the inlet was obtained. The boundary layer formed inner side of the engine had an adverse pressure gradient on the top ramp. Due to this the boundary layer thickens and the static pressure starts to decrease whose effect leads till the trailing edge of inlet. By providing small wedge shaped Micro-Vortex Generator (MVG) where the shockboundary layer occurs we can smooth the boundary layer formed inside the inlet. Thus there will be more efficient compression than the actual case. The results obtained in the present series of tests, could help the hypersonic inlet design optimization at offdesign condition

Flow Field Numerical Optimization of a Large Self-Dumping Truck Hydraulic Tank

2011 ◽  
Vol 94-96 ◽  
pp. 1991-1997 ◽  
Author(s):  
Shui Chang Liu ◽  
Li Fu Li ◽  
Zheng Qi Gu ◽  
Yong Zhang
Keyword(s):  
Heat Exchange ◽  
Flow Field ◽  
Heat Balance ◽  
Numerical Optimization ◽  
Temperature Fluctuations ◽  
Point Temperature ◽  
Hydraulic Oil ◽  
Balance Calculation ◽  
Exit Temperature ◽  
Cfd Method

Various return oil channels of a large self-dumping truck hydraulic tank don’t work synchronously brings the exit temperature fluctuations, traditional heat balance calculation can’t get some point temperature in tank, so it can’t be used to analyze temperature fluctuations. Selecting RNG k-εturbulent model and using CFD method，this paper analyzes flow field in the hydraulic tank of a certain large self-dumping truck at first, then according the principle of enhancing heat exchange, proposes two structure improved schemes, and contrasts the simulation result of two schemes, The results show that the two improved schemes reduce the tank exit temperature fluctuations and the high local temperature at different degrees, and the temperature fluctuations reduce range of the best scheme is 86.51% when the initial hydraulic oil temperature is 40°C.

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