细长体大攻角绕流非对称性形成机理的尺度自适应模拟研究

项目名称： 细长体大攻角绕流非对称性形成机理的尺度自适应模拟研究

项目编号： No.11202101

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 管小荣

作者单位： 南京理工大学

项目金额： 26万元

中文摘要： 细长体大攻角绕流表现出明显的非对称性，这给前体具备细长形状特征的飞行器的飞行控制带来了极大困难，显著降低了飞行器飞行的机动性和敏捷性。本项目拟运用新兴的兼顾计算精度与效率的尺度自适应模拟（Scale-Adaptive Simulation，SAS）方法来研究这一气动难题。在Menter-SAS模型基础上，通过修改von Karman长度尺度构造和升级基准湍流模型来构造一全新SAS模型，能较好预测细长体大攻角绕流，尤其是小尺度涡结构和非定常特性，并结合流动稳定性理论来探讨绕流非对称性形成机理。全新SAS模型除能克服RANS/LES分界面的网格依赖性外，还将计及物面自适应当地涡粘性和雷诺应力非线性效应，从而为非定常大尺度分离湍流的准确预测提供一个新选择。本项目数值研究成果对掌握细长体大攻角绕流确切的流场结构和气动力特性、理解非对称性形成机理、发展大攻角非对称主动控制措施具有重要意义。

中文关键词： 细长体；大攻角；非对称涡流；稳定性理论；尺度自适应模拟

英文摘要： The flow around slender body at high incidence usually shows remarkable asymmetry, which brings immense difficulty in the flight control of aerocraft with slender forebody and then weakens the flight maneuverability and agility of aerocraft. This aerodynamic puzzle is going to be studied in the current work with the rising Scale-Adaptive Simulation (SAS) method that gives considerations to both precision and efficiency of the computation. According to the Menter-SAS model, a fire-new SAS model is to be constructed by both modifying the formation of von Karman length scale and upgrading the basic turbulence model. The fresh SAS model can be employed to more advantageously predict the flow, especially the small-scale vortices and unsteady characteristics, around slender body at high incidence. Based on the computational results, the origin of the flow asymmetry is analyzed combined with the flow stability theory. The fresh SAS model not only gets over the reliance of interface between RANS and LES on grid, but also considers the Wall-Adaptive Local Eddy-viscosity (WALE) and the nonlinear effect of Reynolds stress, which provides a new option for the precise prediction of unsteady turbulent flow with massive separation. The achievements obtained here with numerical method are significant for cognizing the exact flo

英文关键词： slender body；high incidence；asymmetric vortical flow；stability theory；scale-adaptive simulation