COIL压力恢复系统气流主动冷却技术数值模拟

 引射式压力恢复系统是化学激光系统应用中的一个重要组成部分，为了提高引射器引射效率，减小整个系统尺寸，可以采用主动降低光腔出口气流温度的方法。通过数值模拟，开展了用热交换器降低光腔出口气流温度的研究。给出了混合气体的热物理性质、热交换器建模方法及数值模拟条件，比较了不同条件下热交换器性能的差异,发现由于出口气流密度很低，热交换器的总传热系数、压力损失比常规条件下有较大幅度的减小。此时适当增大椭圆管尺寸，采用高翅片换热管，可以有效地提高热交换器的换热能力。

Numerical simulation of cooling technique in COIL pressure recovery system

Ejector-type pressure recovery system plays an important part in the application of chemical lasers. For improving ejector efficiency and reducing system size, an important method is to reduce the temperature of gas mixture out from laser cavity. The feasibility of implementing this method using heat exchanger through numerical simulation is investigated. The thermophysical properties of gas mixture are calculated first, and then modeling methods and numerical simulation conditions are given here. Based on the comparison of heat exchanger performances in different simulation conditions, it is found that the heat transfer efficiency and pressure drop are much smaller than that in common industrial heat exchanger. That's because the density of gas mixture is too low. To enlarge tube size and