航空学报 > 2013, Vol. 34 Issue (10): 2256-2264   doi: 10.7527/S1000-6893.2013.0318

基于CFD方法的直升机前飞状态配平分析

冯德利, 招启军, 徐国华   

  1. 南京航空航天大学 直升机旋翼动力学国家级重点实验室, 江苏 南京 210016
  • 收稿日期:2012-11-01 修回日期:2012-12-17 出版日期:2013-10-25 发布日期:2013-01-05
  • 通讯作者: 招启军,Tel.: 025-84893753 E-mail: zhaoqijun@nuaa.edu.cn E-mail:zhaoqijun@nuaa.edu.cn
  • 作者简介:冯德利 男, 硕士研究生。主要研究方向: 直升机飞行力学、 计算流体力学、 直升机空气动力学。 Tel: 025-84893753 E-mail: fengdeli_1987@126.com;招启军 男, 教授, 博士生导师。主要研究方向: 直升机计算流体力学、 直升机空气动力学及流动控制等。 Tel: 025-84893753 E-mail: zhaoqijun@nuaa.edu.cn;徐国华 男, 教授, 博士生导师。主要研究方向: 直升机空气动力学、 直升机计算流体力学。 Tel: 025-84892117 E-mail: ghxu@nuaa.edu.cn
  • 基金资助:

    国家自然科学基金(11272150)

Trim Analysis of Helicopter in Forward Flight Based on CFD Method

FENG Deli, ZHAO Qijun, XU Guohua   

  1. National Key Laboratory of Rotorcraft Aeromechanics, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China
  • Received:2012-11-01 Revised:2012-12-17 Online:2013-10-25 Published:2013-01-05
  • Supported by:

    National Natural Science Foundation of China (11272150)

摘要:

在直升机非线性全量飞行动力学模型的基础上,提出了一种耦合计算流体力学(CFD)方法的前飞状态配平计算分析方法。为提高传统飞行动力学建模中的直升机旋翼、机身和尾桨等部件的气动力计算精度,降低对试验数据的依赖性,建立了一个以Navier-Stokes方程为控制方程且包含旋翼和尾桨动量源项的直升机气动干扰流场及气动力的计算方法。采用非结构网格技术生成围绕直升机的网格,空间方向采用Jameson中心差分格式进行离散,时间推进采用五步龙格库塔法,并添加人工黏性以抑制解的数值振荡等,同时采用当地时间步长、变系数的隐式残值光顺等方法加速流场收敛。在耦合CFD方法的配平计算中,建立了一种将CFD计算得到的气动力与飞行动力学中的气动力高效耦合的策略。在飞行动力学模型和CFD方法验证的基础上,以UH-60A直升机为研究对象,进行了耦合CFD方法的全机配平分析,最后检验了耦合CFD模型的直升机配平方法的收敛性和精度。结果表明,该方法可以有效地提高配平分析精度,满足工程分析要求。

关键词: 直升机, 旋翼, 飞行动力学, 配平分析, 动量源方法, 计算流体力学

Abstract:

Based on the nonlinear numerical model of flight dynamics developed for a helicopter, a new trim method is proposed by coupling the model with the computational fluid dynamics (CFD) method in forward flight. In order to enhance the calculation precision of aerodynamic forces on aerodynamic components, such as rotor, fuselage, tail-rotor, etc., and reduce dependency on test data, a CFD model based on Navier-Stokes equations is established which includes rotor and tail-rotor momentum sources. Grids around the helicopter are generated by using unstructured grids technology. Jameson central-difference scheme is adopted in spatial discretization and the five-step Runge-Kutta method is used for temporal discretization. Artificial viscosity is added to overcome numerical oscillation of solutions. Local time step method and variable coefficient implicit residual smoothing method are used to accelerate the convergence for the helicopter flowfield. A high-efficient coupling strategy for trimming calculation coupled with CFD method is put forward by coupling the aerodynamic force from the CFD model with that from the flight dynamics model. Then the trim calculations are conducted by taking UH-60A helicopter as a numerical example on the basis of the flight dynamics model and CFD method validations. Special analysis on the precision and convergence rate of the present trim method is performed. It is demonstrated that the trim method can effectively improve trim analysis precision and meet engineering analysis requirements.

Key words: helicopter, rotor, flight dynamics, trimming analysis, momentum source method, computational fluid dynamics

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