The method in [1] has been extended to the case of rotational flow in this paper. A new method for dealing with the shock wave is presented. This method has the advantages of both the shock-fitting and the shock captu...The method in [1] has been extended to the case of rotational flow in this paper. A new method for dealing with the shock wave is presented. This method has the advantages of both the shock-fitting and the shock capturing methods. The direct problem and the mixed direct-inverse prob- lem of the rotational flow in a transonic plane cascade at both design and off design conditions are solved, and the results show that the present method has rapid convergence rate and high accuracy even for the flow with moderately strong shocks. The calculations have been carried out on the DPS-8 computer, and for the direct problem, only 50-80 iterations are needed, and 50-80 seconds of CPU time are required.展开更多
Based on the idea of adjoint method and the dynamic evolution method,a new optimum aerodynamic design technique is presented in this paper.It can be applied to the optimum problems with a large number of design variab...Based on the idea of adjoint method and the dynamic evolution method,a new optimum aerodynamic design technique is presented in this paper.It can be applied to the optimum problems with a large number of design variables and is time saving.The key of the new method lies in that the optimization process is regarded as an unsteady evolution,i.e.,the optimization is executed,simultaneously with solving the unsteady flow governing equations and adjoint equations.Numerical examples for both the inverse problem and drag minimization using Euler equations have been presented,and the results show that the method presented in this paper is more efficient than the optimum methods based on the steady flow solution and the steady solution of adjoint equations.展开更多
On the basis of the frequency domain acoustic solation of sources in arbitrary motion, in this paper an approximate acoustic solution of a rotating point source in near field is given, which is the superposition of th...On the basis of the frequency domain acoustic solation of sources in arbitrary motion, in this paper an approximate acoustic solution of a rotating point source in near field is given, which is the superposition of the well-Known far field solution and three near field modification items on the condition that the rotating radius is acoustically compact compared with the field sound wavelength. Accordingly the near field Green function in free space is obtained. The characteristic directionality of the sound field induced by source rotating is discussed, and the influences of source position, source frequency and rotating frequency are studied in detail.展开更多
文摘The method in [1] has been extended to the case of rotational flow in this paper. A new method for dealing with the shock wave is presented. This method has the advantages of both the shock-fitting and the shock capturing methods. The direct problem and the mixed direct-inverse prob- lem of the rotational flow in a transonic plane cascade at both design and off design conditions are solved, and the results show that the present method has rapid convergence rate and high accuracy even for the flow with moderately strong shocks. The calculations have been carried out on the DPS-8 computer, and for the direct problem, only 50-80 iterations are needed, and 50-80 seconds of CPU time are required.
文摘Based on the idea of adjoint method and the dynamic evolution method,a new optimum aerodynamic design technique is presented in this paper.It can be applied to the optimum problems with a large number of design variables and is time saving.The key of the new method lies in that the optimization process is regarded as an unsteady evolution,i.e.,the optimization is executed,simultaneously with solving the unsteady flow governing equations and adjoint equations.Numerical examples for both the inverse problem and drag minimization using Euler equations have been presented,and the results show that the method presented in this paper is more efficient than the optimum methods based on the steady flow solution and the steady solution of adjoint equations.
文摘On the basis of the frequency domain acoustic solation of sources in arbitrary motion, in this paper an approximate acoustic solution of a rotating point source in near field is given, which is the superposition of the well-Known far field solution and three near field modification items on the condition that the rotating radius is acoustically compact compared with the field sound wavelength. Accordingly the near field Green function in free space is obtained. The characteristic directionality of the sound field induced by source rotating is discussed, and the influences of source position, source frequency and rotating frequency are studied in detail.
