A study on a Mars airplane propeller operating at a low Reynolds number and a high Mach number

为了研制火星飞行器螺旋桨，通过3个风洞试验和CFD分析，研究了雷诺数1000量级、高马赫数（桨尖马赫数0.5左右）下螺旋桨的工作特性。以下是明确的。(1)在高雷诺数下设计螺旋桨的方法，即Adkins和Liebeck提出的方法，在目前的雷诺数下是可用的。(2)我们提出了一个翼型形状具有较高的最大升阻比。(3)雷诺数越小，压缩性对翼型特性的影响越小。(4)叶片的展弦比随雷诺数的减小而减小。(5)存在通过后掠角和上反角的变化来改善螺旋桨的特性的可能性。这是因为这些角度的变化会影响上表面上的旋涡的位置。

In oreder to develop a propeller of a Mars airplane, the characteristics of a propeller operating at a Reynolds number with the order of 1000 and a high Mach number (Mach number at tip is about 0.5) were investigated by experiments at three wind tunnels and CFD analysis. The followings have been made clear. (1) A method used for designing a propeller at a high Reynolds number, that is a method proposed by Adkins and Liebeck, is available at the present Reynolds number. (2) We proposed an airfoil shape with a high maximum lift-drag ratio. (3) An effect of compressibility on the charactericts of an airfoil is smaller with the decrease of Reynolds number. (4) Aspect ratio of a blade is smaller with the decrease of Reynolds number.(5) There is possibility that characteristics of a propller can be improved by the variations of a sweepback angle and a dihedral angle. This is because position of vortices on the upper surface is affected by the variations of these angles.