直流低速风洞扩散段整流装置组合设计

Combined design of flow adjusting device in diffuser of open-circuit wind tunnel with low speed

扩散段是风洞主要部段之一,在扩散段中添加整流装置对抑制流动分离、提高流场品质具有重要作用。针对直流吹气式低速风洞的扩散段,设计了由收缩锥、导流板、丝网等3个级段组成的整流装置;基于CFX软件建立扩散段的流场特性分析模型,采用RNG k-ε湍流模型并结合适当的边界条件分析了收缩锥、导流板、丝网及结构参数对流场品质的影响。研究表明单级整流装置的作用有限,三者组合使用与结构参数优化将大大改善扩散段出口流场品质。研究结果对实用低速风洞扩散段整流装置设计具有重要参考意义。

The diffuser is one of important parts on wind tunnel. Appropriate flow adjusting device assembled in diffuser could suppress flow separation and improve flow field quality. A new flow adjusting device was designed for diffuser in open-circuit wind tunnel with low speed, which was composed of three parts, namely contracting cone, air guide plate and screen.Analysis model of flow field for diffuser was established using CFX software. The influences of contracting cone, air guide plate and screen on flow field quality were respectively worked out by CFX simulation with appropriate boundary conditions and RNG k-ε turbulence model. The research result shown that the role of single part is limited, combined effect and optimizing structural parameters of three parts in flow adjusting device can greatly improve the quality of flow field in diffuser. Research results mentioned above are useful for designing flow adjusting device in diffuser of practical open-circuit wind tunnel with low speed.