Applying inviscid linear unsteady lifting-line theory to viscous large-amplitude problems
Applying inviscid linear unsteady lifting-line theory to viscous large-amplitude problems
复制标题
将非粘性线性非定常升力线理论应用于粘性大振幅问题
DOI：
--
复制
发表时间：
2021
期刊：
影响因子：
--
通讯作者：
I. M. Viola
中科院分区：
文献类型：
--
作者：
Hugh J. A. Bird;K. Ramesh;Shūji Ōtomo;I. M. Viola
非定常升力线理论(ULLT)是一种低阶方法，能够以较低的计算代价模拟非定常和有限机翼的相互作用效应。该方法的大多数公式假定无粘流和小振幅。虽然这些假设可能适用于高雷诺数下的小幅气动弹性问题，但现代工程应用越来越多地涉及到低雷诺数、大振幅运动学和导致气动非线性的涡旋结构。本文通过将ULLT的计算结果与实验验证的Re=10000时的计算流体力学模拟的结果进行比较，证明ULLT仍然为低雷诺数、大振幅的运动学问题提供了很好的解决方案。三维(3D)效应稳定了前缘涡(LEV)结构，使得ULLT能够很好地预测整个翼力系数。虽然无粘展向力分布对于小振幅运动学是准确的，但ULLT不能模拟3D涡旋结构，因此它不能正确地预测由于杠杆引起的力分布。然而，通过前缘吸力参数判据，它可以在有限的程度上预测Levs的脱落。然后，这可以用作力分布结果的有用性的指示器。
Unsteady Lifting-Line Theory (ULLT) is a low order method capable of modeling interacting unsteady and finite wing effects at low computational cost. Most formulations of the method assume inviscid flow and small amplitudes. Whilst these assumptions might be suitable for small-amplitude aeroelastic problems at high Reynolds numbers, modern engineering applications increasingly involve lower Reynolds numbers, large amplitude kinematics and vortex structures that lead to aerodynamic non-linearities. This paper establishes that ULLT still provides a good solution for low Reynolds number, large-amplitude kinematics problems, by comparing ULLT results against those of experimentally validated computational fluid dynamics simulations at Re=10 000. Three-dimensional (3D) effects stabilize Leading Edge Vortex (LEV) structures, resulting in a good prediction of whole wing force coefficients by ULLT. Whilst the inviscid spanwise force distributions are accurate for small-amplitude kinematics, the ULLT cannot model 3D vortical structures, and thus it cannot correctly predict the force distribution due the LEV. It can however predict the shedding of LEVs to a limited extent via the leading edge suction parameter criterion. This can then be used as an indicator of the usefulness of the force distribution results.
DOI：
10.2514/6.2019-1377
发表时间：
2019
期刊：
--
影响因子：
--
作者：
Bird H
通讯作者：
Bird H
薄翼型非定常流中的前缘吸力和驻点位置
影响因子：
3.7
作者：
Ramesh K
通讯作者：
Ramesh K