变流量与变压升的多功能低速回流风洞气动设计
Aerodynamic Design of Multi-Function Low-Speed Wind Tunnel with Variable Flow Rate and Variable Pressure Rise

对于研究型低速回流风洞，其多功能试验能力需求决定了风洞具有不同尺寸的可互换试验段，且不同试验段具有不同的风速范围。对于这种类型的风洞，因不同试验段共用同一套动力系统，这样可能会导致风洞的流量与压升不匹配的问题。为解决这一类问题，提出以风洞动力系统最大功率需求为依据，合理选择风洞收缩比、优化匹配风洞各部段，使风洞在满足最大试验风速的条件下具有低湍流度、低噪声且流场均匀的高品质流场。采用变桨距风扇设计，通过调节风扇叶片安装角使风洞满足变流量与变压升需求。通过风洞声学设计，明确了风洞噪声源与声学特性，针对性选择不同消声方式使风洞满足低背景噪声需求。
For a research-type low-speed recirculating wind tunnel, the multi-functional test capability requirements determine that the wind tunnel has interchangeable test sections of different sizes, and different test sections have different wind speed ranges. For this type of wind tunnel, because different test sections share the same set of power systems, it may lead to the problem of mismatched flow and pressure rise. To solve this type of problem, it is proposed to choose the wind tunnel contraction ratio based on the maximum power demand of the wind tunnel power system and optimize the matching of the wind tunnel sections to ensure that the wind tunnel has a high-quality flow field with low turbulence, low noise, and uniform flow field while meeting the maximum test wind speed conditions. The design of variable pitch propeller is adopted to meet the variable flow and pressure rise requirements by adjusting the installation angle of the propeller blades. The acoustic design of the wind tunnel clarifies the noise sources and acoustic characteristics, and targeted selection of different noise reduction methods is used to meet the low background noise requirements of the wind tunnel.