汽车空调箱内空气流动的数值模拟研究

摘要

The mathematical model of automobile air conditioning box is established. Combined with a single blow experiment of heat exchanger, the pressure loss of the air between evaporator and heater cores is calculated by using the porous media model. Through analyzing the velocity field and pressure field inside the heat exchangers, the air flow characteristic in the air conditioner is revealed. The results show that the pressure loss of the evaporator is small because of bigger windward area of the evaporator. At the heater cores, its velocity field is non-uniform, because the channel expansion is not sufficient. Reflux occurs at the air conditioner edge, the heat transfer efficiency of the core is reduced. There is stronger vortex at the exit of the air conditioner. It is the main source of air conditioner’s pressure loss.%建立了汽车空调箱的数学模型，与换热器的单体吹风实验结合，采用多孔介质模型计算了空气在蒸发器与暖风芯体间的压力降。通过分析换热器内部速度场、压力场，揭示了空气在空调箱内的流动特性。结果表明：由于蒸发器迎风面积较大，蒸发器侧的压力损失不高，而在暖风芯体处，由于通道扩张不充分，芯体处的速度场不均匀，流体在箱体边缘发生了回流，降低了芯体的换热效能。在出口处，存在较强涡流，是空调箱阻力的主要来源。