The Steady Aerodynamics of Quiet Airfoils with Porosity Gradients
The Steady Aerodynamics of Quiet Airfoils with Porosity Gradients
复制标题
具有孔隙率梯度的静音翼型的稳态空气动力学
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
J. Jaworski
中科院分区：
文献类型：
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作者：
Rozhin Hajian;J. Jaworski
本理论研究确定了在稳定不可压缩流动中具有规定孔隙率分布的薄翼型的气动载荷。在孔隙度分布为hold连续的条件下，翼型表面的Darcy孔隙度条件提供了Fredholm积分方程，该方程可以作为Riemann-Hilbert问题精确求解。对规定的分布、升力系数和力矩系数以及渗流阻力的预测简化为正交，并在均匀孔隙度翼型的特殊情况下得到封闭表达式，与文献中的既定结果一致。最后，以部分多孔翼型为例，研究了一类在一定参数极限下接近于分段不连续函数的可微孔隙度分布。我们的一般holder -连续解在这一极限下得到了文献中部分多孔结果的进一步验证，并且可以整合到一个理论框架中，在对气动性能影响最小的情况下优化湍流噪声抑制。
This theoretical study determines the aerodynamic loads on a thin airfoil with a prescribed porosity distribution in a steady incompressible flow. A Darcy porosity condition on the airfoil surface furnishes a Fredholm integral equation, which is solved exactly and generally as a Riemann-Hilbert problem provided that the porosity distribution is Holdercontinuous. Predictions for the prescribed distribution, lift and moment coefficients, and seepage drag are reduced to quadrature, and closed-form expressions are obtained in the special case of an airfoil with uniform porosity, which agree with established results in the literature. Finally, we study a class of differentiable porosity distributions, that approach a piecewise, discontinuous function in a certain parametric limit, which is representative of partially-porous airfoils. Our general Holder-continuous solution is further verified in this limit against partially-porous results in literature and may be integrated into a theoretical framework to optimize turbulence noise suppression with minimal impact to aerodynamic performance.