【摘要】 风洞收缩段的收缩曲线设计是直流式低速风洞设计至关重要的部分,直接影响试验段核心区域的气流品质。使用Matlab绘制了现行的维氏曲线、双三次曲线、五次方曲线及6种五次方曲线的改进形式,比较它们在轮廓上的差别,并初步预测它们对风洞气流品质的影响。利用Fluent软件对比分析不同收缩曲线的直流式低速风洞模型的收缩段和试验段风速轮廓,综合比较了不同风洞模型试验段核心区域气流的动压系数、速度不均匀度和轴向静压梯度特性。结果表明:双三次曲线风洞模型综合性能最优,五次方曲线改进形f(ε)=x/L次之。更多还原

【Abstract】 Contraction curve is an important factor in the design of low-speed blow down wind tunnel.There are mainly three kinds of contraction curves,including Witozinsky curve,bicubic curve and fifth degree polynomial curve.In addition,six transformations of the fifth degree polynomial curve are developed.The profiles of the contraction curves mentioned above were drawn by Matlab.Then the nine low-speed blow down wind tunnel models with different contraction curves were analyzed by Fluent.Results indicate that bicubic curve and one of transformations of the fifth degree polynomial f(ε)=x/L have better air quality in the working section than others.更多还原