该文基于SM AC(s im p lified m arker and ce ll)方法,发展了一种在任意曲线坐标系中求解三维粘性不可压湍流R eyno lds时均方程的全隐式数值方法。基本方程是以逆变速度为变量的R eyno lds时均动量方程和椭圆型压力Po isson方程,并采...该文基于SM AC(s im p lified m arker and ce ll)方法,发展了一种在任意曲线坐标系中求解三维粘性不可压湍流R eyno lds时均方程的全隐式数值方法。基本方程是以逆变速度为变量的R eyno lds时均动量方程和椭圆型压力Po isson方程,并采用标准k-ε湍流模型封闭方程组。压力Po isson方程用T schebyscheff SLOR方法交替方向迭代求解。R eyno lds时均动量方程、k方程和ε方程对流项均采用Chakravarthy-O sher TVD格式离散,该格式不但有助于提高数值稳定性,而且能有效消除网格扭曲较大的地方产生的非物理振荡误差。用自编程序对后台阶方腔流场进行了计算,计算结果和实验结果吻合较好。展开更多
Based on the immersed boundary method,a fast simulation for solving unsteady,incompressible,viscous flow associated with the oscillating cascade is established on a quasi-three-dimensional coordinate system.The numeri...Based on the immersed boundary method,a fast simulation for solving unsteady,incompressible,viscous flow associated with the oscillating cascade is established on a quasi-three-dimensional coordinate system.The numerical method is applied to the simulation of the flow passing an oscillating circular cylinder which is forced to move in X direction under prescribed motions in water at rest at low Keulegan-Carpenter numbers.Then vor-tex-induced vibration of a cylinder with two degrees of freedom which oscillates in in-line direction and transverse direction is simulated using this method.The results are in good agreement with the previous research.Then the method is extended to the oscillating cascade simulation of making various comparisons.It is found that the IBPA(inter blade phase angle) will change as the time goes on,because of the non-uniformity of the flow in the circumferential direction,until the oscillating cascade goes to a stable situation.The reduced velocity and the number of blades are chosen to investigate the effects of them on IBPA.The results indicate that both the reduced velocity and the number of blades are the main factors which influence IBPA.It is worth noting that the coupling process is not necessary to generate any body-fitting grids,which makes it much faster in computational process for such a complicated fluid-structure interaction problem.展开更多
文摘该文基于SM AC(s im p lified m arker and ce ll)方法,发展了一种在任意曲线坐标系中求解三维粘性不可压湍流R eyno lds时均方程的全隐式数值方法。基本方程是以逆变速度为变量的R eyno lds时均动量方程和椭圆型压力Po isson方程,并采用标准k-ε湍流模型封闭方程组。压力Po isson方程用T schebyscheff SLOR方法交替方向迭代求解。R eyno lds时均动量方程、k方程和ε方程对流项均采用Chakravarthy-O sher TVD格式离散,该格式不但有助于提高数值稳定性,而且能有效消除网格扭曲较大的地方产生的非物理振荡误差。用自编程序对后台阶方腔流场进行了计算,计算结果和实验结果吻合较好。
文摘Based on the immersed boundary method,a fast simulation for solving unsteady,incompressible,viscous flow associated with the oscillating cascade is established on a quasi-three-dimensional coordinate system.The numerical method is applied to the simulation of the flow passing an oscillating circular cylinder which is forced to move in X direction under prescribed motions in water at rest at low Keulegan-Carpenter numbers.Then vor-tex-induced vibration of a cylinder with two degrees of freedom which oscillates in in-line direction and transverse direction is simulated using this method.The results are in good agreement with the previous research.Then the method is extended to the oscillating cascade simulation of making various comparisons.It is found that the IBPA(inter blade phase angle) will change as the time goes on,because of the non-uniformity of the flow in the circumferential direction,until the oscillating cascade goes to a stable situation.The reduced velocity and the number of blades are chosen to investigate the effects of them on IBPA.The results indicate that both the reduced velocity and the number of blades are the main factors which influence IBPA.It is worth noting that the coupling process is not necessary to generate any body-fitting grids,which makes it much faster in computational process for such a complicated fluid-structure interaction problem.
