高超声速低密度风洞带中心锥型扩压器性能研究

扩压器是超/高超声速风洞的关键部件之一，直接影响风洞运行的费效比。然而，对于高超声速低密度风洞而言，试验运行参数范围大、试验气体密度又相对较低，常规的"收缩段-等直段-扩张段"的扩压器结构扩压作用不明显。提出一种带中心锥型扩压器新结构，并在Φ300 mm高超声速低密度风洞中进行扩压性能试验。研究了M16喷管小流量稀薄状态和M8喷管大流量近连续流状态下带中心锥型扩压器的扩压性能，同时，分析了试验段模型对扩压器扩压能力的影响。结果表明带中心锥结构的扩压器适用的风洞运行参数范围更广、扩压性能更优，能有效提高设备试验能力，可为高超声速风洞扩压器设计提供参考。

Study on the efficiency of a new central-type diffuser for hypersonic low density wind tunnel

The diffuser is one of the key components of the supersonic and hypersonic wind tunnels, which directly affects the efficiency-cost ratio of the wind tunnel operation. However, for the hypersonic low density wind tunnel, the range of operating parameters is large and the test gas density is relatively low, and thus the effects of the conventional diffuser with "contraction section, equi-straight section and expansion section" are not obvious. In this paper, a new central-type diffuser structure is presented, and the efficiency of the central-type diffuser is tested at the Φ300 mm hypersonic low density wind tunnel for M16 small flow rate states and M8 large flow rate states. At the same time, the influence of the test section model on the diffuser's capacity is analyzed. The results show that the central-type diffuser has a wide range of operation parameters and a significant pressure increase efficiency, and can effectively improve the wind tunnel test capability. This study can provide a reference for the design of the hypersonic wind tunnel diffuser.