摘要
对快速多极展开算法(FMM)在共轴式和纵列式双旋翼自由尾迹互诱导速度计算中的应用进行了研究。介绍了FMM算法的基本原理,建立了FMM算法的数学计算模型,并对其加速特性和准确性进行了分析;将方法引入到基于直涡元的自由尾迹互诱导速度的计算分析中,推导了诱导速度的多极展开表达式。在此基础上,以某旋翼模型为例,通过对自由尾迹中涡元诱导速度的计算,验证了加速算法的加速度特性和准确性。使用方法对共轴式和纵列式双旋翼悬停和前飞状态下的自由尾迹几何形状进行了计算,分析了双旋翼之间的相互干扰。
A research of the application of 3 - D fast muhipole method （FMM） in the calculation of the inter-induced velocity produced by the free wake of coaxial and longitudinal twin- rotor systems is conducted. First, the paper presents the basic mathematic principles of FMM and establishes its mathematic model, and then the accelerating characteristic and accuracy of this method is analyzed. Second, intro- duces FMM into the calculation of the induced velocity produced by linevortex elements, and the expression of their induced-velocity is derived. Furthermore, by the calculation of the induced-velocity of vortex elements in a rotor wake of a certain model, the accelerating characteristic and accuracy of this method is validated. Finally, the shapes of free wake of coaxial and longitudinal twinrotor models are computed in hover and forward flight conditions by using the method, to analyze the interinfluence of the two rotors.
出处
《航空计算技术》
2013年第2期51-55,共5页
Aeronautical Computing Technique
