Large Eddy Simulation Of Chevron Corrugated Plate Heat Exchanger

The flow channel of plate heat exchanger is complex, so the flow in plate heat exchanger may have a strong anisotropy. However, most scholars choose RANS model which cannot describe anisotropic turbulence accurately to simulate the flow. So, I build complete geometrical models of chevron corrugated plate heat exchanger, and simulate them with LES model which can describe anisotropic turbulence accurately.The main work is as follows:(1) The applicability of numerical model in simulating chevron corrugated plate heat exchanger. I choose standard k-? model (one of RANS models) and LES model to simulate the flow in one flow channel of 55°chevron corrugated plate heat exchanger, and compare the results with PIV experimental results. I find that the PIV experiment results have a better consistency with the simulation results of LES model. So we should use LES model instead of RANS model to simulate the flow in chevron corrugated plate heat exchanger. This provides evidence in choosing numerical model while simulating plate heat exchanger.(2) The flow and heat transfer characteristics of chevron corrugated plate heat exchanger. I choose LES model to simulate the flow and heat transfer in three flow channels of 25°chevron corrugated plate heat exchanger and 55°chevron corrugated plate heat exchanger, and analyze flow pattern,velocity, heat flux, velocity fluctuation, turbulent kinetic energy, temperature,temperature fluctuation and turbulent heat flux. I find that the velocity near heat exchange surfaces is the main factor of the heat flux. The heat flux increases with parallel velocity and normal velocity. Besides, turbulent kinetic energy, RMS static temperature are determined by RMS X velocity and RMS Y velocity. The conclusions can help increase heat flux and get heat transfer mechanism.(3) The corrugation angel ? influence on flow and heat transfer. I compare the simulation results of 25°chevron corrugated plate heat exchanger with the simulation results of 25°chevron corrugated plate heat exchanger.When ? is 25°,only a small amount of fluid change flow direction in the junction of two corrugation channels, and the main velocity is between 0.5?0.8 m · s-1; When ? is 55°,more fluid change flow direction in the junction of two corrugation channels, and the main velocity is between 1?1.4 m · s-1.RMS X velocity, RMS Y velocity, RMS Z velocity, turbulent kinetic energy,RMS static temperature, heat transfer coefficient and pressure drop increase with corrugation angel ?.