旋成体表面沟槽减阻试验研究

在旋成体模型表面粘贴铝基沟槽蒙皮,研究沟槽表面对模型阻力的影响。给出基于来流单位雷诺数的沟槽尺寸无量纲公式,用于设计沟槽齿高和齿宽,依据试验风洞的单位雷诺数范围,选定3种尺寸的沟槽进行减阻试验。结果表明,在旋成体表面湍流流动区域顺流向布置沟槽,当沟槽齿高和齿宽的无量纲值h＋、s＋均小于25时,在小迎角下具有减阻作用,当s＋约为15时减阻效果最明显,可减小约3%～4%的阻力。

Experiment investigation of drag reduction using riblets for a slender body

To evaluate the drag reduction effect of riblet technology,aluminum fairings with riblet surface are applied on a slender body and investigated in wind tunnel test.For optimizing riblet height and space efficiently,normalized geometry parameters based on free stream unit Reynolds number are adopted in this article and three different riblet geometries are chosen for test,considering the range of wind tunnel＇s unit Reynolds number.According to the test result,with riblet allocated in turbulence area and along free stream direction,drag reduction effect can be observed in lower angle of attack conditions if normalized parameters h＋ and s＋ are no more than 25.The maximum drag reduction of 3%~4% can be achieved when s＋ is about 15.