摘要
采用雷诺平均Navier-Stokes (RANS)方法结合基于当地变量的γ-Reθ转捩预测模型,针对某特殊布局形式的层流机翼验证机开展跨声速层流特性和参数敏感性分析。通过DLR F-5三维机翼构型对基于RANS的转捩预测方法进行算例验证分析,同时将某层流验证机中央翼段层流转捩预测结果与试验进行对比,证明了采用的计算方法完全适用于所研究问题。研究重点关注全机巡航状态附近的气动特性和中央验证段在不同飞行状态下的表面转捩位置及层流区长度。通过计算,进一步分析了层流流动对全机升阻及力矩特性的影响。结果表明:马赫数、雷诺数、来流湍流度、迎角等均会对中央验证段表面转捩位置产生明显的影响,影响规律差异较大。马赫数的增加会引起压力分布的较大变化,使转捩位置前后波动;雷诺数按同样幅度递增会使翼面转捩位置有规律地提前;来流湍流度和迎角的增加会导致转捩提前,层流区长度明显缩小。
In this paper, the Reynold-Averaged Navier-Stokes(RANS) method is combined with the γ-Reθtransition model based on local variables to investigate the transonic laminar flow characteristics and parameter sensitivity of a specially designed aircraft with laminar wing section. The RANS-based transition prediction method is validated and analyzed by the transition prediction of the DLR F-5 three-dimensional wing. The simulation results of the laminar wing section of the aircraft are compared with the corresponding experimental data, with the pressure distribution and transition location on the upper surface both showing good agreement with each other;thus proving the applicability of the calculation method proposed in this paper. This article mainly focuses on the aerodynamic characteristics of the whole aircraft in the cruise state, and the transition location and the length of the laminar flow zone on the upper surface of the middle laminar wing section under different flight conditions. According to the calculation results, the influence of laminar flow on the lift, drag and moment of the whole aircraft are further analyzed. The influence of key flow parameters such as Mach number, Reynolds number, freestream turbulence intensity and angle of attack on the transition position of the wing section surface are summarized. The results demonstrate that the transition position on the surface of the middle laminar wing section is impacted significantly by the Mach number, Reynolds number, turbulence intensity and angle of attack of the free stream. The increase of the Mach number will cause a great change in the pressure distribution, and make the transition position move forward and backward. The increase of the Reynolds number by the same amplitude will make the transition position move forward regularly. The increase in the turbulence intensity and angle of attack of the freestream will directly lead to the occurrence of an early transition, and the length of the laminar flow zone will be significantly reduced gradu
作者
牛笑天
李杰
周智鹏
杨钊
昌陌尘
NIU Xiaotian;LI Jie;ZHOU Zhipeng;YANG Zhao;CHANG Mochen(School of Aeronautics,Northwestern Polytechnical University,Xi'an 710072,China)
出处
《航空学报》
EI
CAS
CSCD
北大核心
2022年第11期258-275,共18页
Acta Aeronautica et Astronautica Sinica
基金
国家自然科学基金(11972304)。
关键词
自然层流
层流机翼
跨声速层流特性
层流特性敏感性
γ-Reθ转捩模型
natural laminar flow
laminar wing section
transonic laminar flow characteristic
sensitivity of laminar flow
γ-Re_(θ) transition model
