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 A numerical method is presented for predicting the aerodynamic characteristics of elastic aircraft under quasistatic approximation. This method can be used to evaluate the lift distribution and 11 main longitudinal aerodynamic derivatives of elastic aircraft at subsonic speeds. The aerodynamic calculations are based on the Green's function method. The structure deformation is evaluated by the free structure influence coefficient method. The combination of these methods can provide an efficient,... A numerical method is presented for predicting the aerodynamic characteristics of elastic aircraft under quasistatic approximation. This method can be used to evaluate the lift distribution and 11 main longitudinal aerodynamic derivatives of elastic aircraft at subsonic speeds. The aerodynamic calculations are based on the Green's function method. The structure deformation is evaluated by the free structure influence coefficient method. The combination of these methods can provide an efficient, general and flexible aerodynamic tool for design of elastic aircraft.Several numerical examples are given and some dynamical problems of elastic aircraft are also discussed in this paper. The derivatives evaluated in this paper can be directly adopted in analysis of stability and control of elastic aircraft.  本文介绍一种准静弹性飞机气动特性的数值计算方法。可以用它来计算亚音速时弹性飞机的升力分布及11个主要的纵向气动导数。 文中附有算例,并对准静弹性飞机动态特性方面的一些问题进行了分析和讨论。 本文所得的导数可直接用于弹性飞机操纵性与稳定性的分析。  Modern large aircraft have become increasingly flexible, causing its deformation to become increasingly large. We contracted to develop an analysis method for calculating loads acting on flexible aircraft wing with its real deformation considered. In this paper, we explain in much detail the analysis method we developed under contract. Here we give only a briefing of our method. It involves the calculation of aerodynamic loads followed by calculation of deformation; this cycle is repeated again and again until... Modern large aircraft have become increasingly flexible, causing its deformation to become increasingly large. We contracted to develop an analysis method for calculating loads acting on flexible aircraft wing with its real deformation considered. In this paper, we explain in much detail the analysis method we developed under contract. Here we give only a briefing of our method. It involves the calculation of aerodynamic loads followed by calculation of deformation; this cycle is repeated again and again until the actual aerodynamic loads and the actual deformation of wing are both obtained. The aerodynamic loads are calculated by solving NavierStokes equations with the second order implicit LUNND algorithm; the structure deformation is calculated by structure influence coefficient method. In this paper, we take a sweptback wing as numerical example and the numerical simulation results obtained with our method show preliminarily that our method is feasible. The numerical example also contains a number of interesting results that correspond to the discussion of the detailed explanation of our method given in this paper.  以 N S方程为控制方程计算机翼气动力 ,考虑机翼的结构弹性的影响 ,采用结构影响系数法建立结构平衡方程计算弹性变形 ,两个方程相互迭代耦合求解 ,计算弹性飞机飞行中的真实载荷 ,并在已知弹性机翼飞行时总载荷的情况下 ,确定结构弹性在飞行中对载荷的贡献  In order to study in depth the static aeroelastic characteristics of supercritical wing,we present the analysis method we developed.The feature of our analysis method is that we employ Euler equations for aerodynamic calculations.As usual,our analysis method involves the calculation of aerodynamic loads followed by calculation of deformation;this cycle is repeated again and again until the actual aerodynamic loads and the actual deformation of wing are both obtained.The aerodynamic loads are calculated by solving... In order to study in depth the static aeroelastic characteristics of supercritical wing,we present the analysis method we developed.The feature of our analysis method is that we employ Euler equations for aerodynamic calculations.As usual,our analysis method involves the calculation of aerodynamic loads followed by calculation of deformation;this cycle is repeated again and again until the actual aerodynamic loads and the actual deformation of wing are both obtained.The aerodynamic loads are calculated by solving Euler equations with a finite volume algorithm based on center difference;the structure deformation is calculated by structure influence coefficient method.We take a sweptback wing as numerical example and the numerical simulation results obtained with our method show preliminarily that our method is feasible.We also calculate the static aeroelastic deformation for three wings(swept back wing,straight wing,forward swept wing) that adopt supercritical airfoil(RAE2822) or general airfoil(NACA0012 or NACA64A006) with total lift unchanged;we find that the center of rigidity for the forward swept wing is at the 40.0% of chord,the pressure center for the generalairfoil NACA0012 wing is at the 26.1% of chord,the pressure center for the supercriticalairfoil wing is at the 50.4% of chord.Obviously,the pressure center of supercritical wing shifts backwards;this is the main reason why pitching up deformation of supercritical wing is less than that of general wing.  采用三维Eu ler方程为控制方程,计算机翼所受的气动力与静气动弹性平衡方程耦合求解,研究超临界机翼的静气动弹性规律,并以超临界弹性机翼和普通弹性机翼为算例,计算弹性飞机飞行中的真实载荷和扭转变形,并在已知弹性机翼飞行时总载荷保持不变的情况下,确定超临界机翼结构弹性在飞行中对载荷的影响。   << 更多相关文摘 
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