平流层飞艇螺旋桨相似准则分析与验证

根据螺旋桨相似理论,选择等Re数和等前进比作为一组相似准则.通过数值模拟验证该相似准则组合的正确性和适用性,着重研究密度对螺旋桨相似性参数的影响,并将螺旋桨数值计算结果与缩比模型地面常规密度风洞试验的有关结果进行了对比分析.结果表明:数值模拟的不同工作高度下螺旋桨无量纲气动力系数相互重合,螺旋桨数值计算结果和地面风洞试验结果基本吻合,表明在所选择的相似准则下,密度基本不影响螺旋桨相似性参数.平流层飞艇螺旋桨可以在地面常规密度风洞中按照等Re和等前进比相似准则进行缩比模型试验,为平流层螺旋桨的试验研究提供参考依据.

Study and verification on similarity theory for propellers of stratospheric airships

According to similarity theory of propellers,equal Reynolds number and equal advanced ratio similarity was selected as a group of similarity criterion combination.The effect of different density on the propeller similarity criterion was investigated by using numerical simulation.The chosen similarity criterion and correctness of applicability were verified.The relevant test results obtained by using the ground wind tunnel test on the scaled propeller model and the numerical simulation results of the stratosphere propellers were compared and analyzed.The results show that the nondimensional aerodynamic character curves of propellers at different altitudes are nearly agreement with each other.And the experimental results in ground wind tunnel is corresponding to the results of numerical simulations.It means that the air density influences little of propeller similarity parameters.So that,the scaled model experiment of propeller for stratospheric airships in ground wind tunnel is feasible according to equal Reynolds number and advanced ratio similarity,and provides reference basis for the wind tunnel test of propellers in stratosphere.