Algebraic methods and rapid deforming techniques are used to generate three-dimensional boundary-fitted dynamic grids for assemblies. The conservative full-potential equation is solved by a time-accurate approximate f...Algebraic methods and rapid deforming techniques are used to generate three-dimensional boundary-fitted dynamic grids for assemblies. The conservative full-potential equation is solved by a time-accurate approximate factorization algorithm and internal Newton iterations. An integral boundary layer method based on the dissipation integral is used to account for viscous effects. The computational results about unsteady transonic forces on wings, bodies and control surfaces are in agreement with experimental data.展开更多
This article is the written version of a lecture given at the Festkolloquium on the occasion of Prof. Dr.-Ing. Dr.techn. E.h. Jtirgen Zierep＇s 80th birthday held at the Universitat Karlsruhe, 21 January 2009. It deal...This article is the written version of a lecture given at the Festkolloquium on the occasion of Prof. Dr.-Ing. Dr.techn. E.h. Jtirgen Zierep＇s 80th birthday held at the Universitat Karlsruhe, 21 January 2009. It deals with laminar viscous inviscid interactions in transonic narrow channel flows. Special emphasis is placed on the internal structure of pseudo-shocks and properties of nozzle flows. Also, it is shown that the theory, first formulated for perfect gases, can easily be extended to the case of general single phase fluids.展开更多
A quasi-simultaneous viscous/inviscid interaction model and a new integral method are tried to predict twodimensional incompressible turbulent boundary-layer separating flows. The results are compared with experiment...A quasi-simultaneous viscous/inviscid interaction model and a new integral method are tried to predict twodimensional incompressible turbulent boundary-layer separating flows. The results are compared with experiments and other prediction.展开更多
To compute transonic flows over a complex 3D aircraft configuration, a viscous/inviscid interaction method is developed by coupling an integral boundary-layer solver with an Eluer solver in a ＂semi-inverse＂ manner. ...To compute transonic flows over a complex 3D aircraft configuration, a viscous/inviscid interaction method is developed by coupling an integral boundary-layer solver with an Eluer solver in a ＂semi-inverse＂ manner. For the turbulent boundary-layer, an integral method using Green＇s lag equation is coupled with the outer inviscid flow. A blowing velocity approach is used to simulate the displacement effects of the boundary layer. To predict the aerodynamic drag, it is developed a numerical technique called far-field method that is based on the momentum theorem, in which the total drag is divided into three component drags, i.e. viscous, induced and wave-formed. Consequently, it can provide more physical insight into the drag sources than the often-used surface integral technique. The drag decomposition can be achieved with help of the second law of thermodynamics, which implies that entropy increases and total pressure decreases only across shock wave along a streamline of an inviscid non-isentropic flow. This method has been applied to the DLR-F4 wing/body configuration showing results in good agreement with the wind tunnel data.展开更多
基金Aeronautical Science Foundation of China (99A52007)
文摘Algebraic methods and rapid deforming techniques are used to generate three-dimensional boundary-fitted dynamic grids for assemblies. The conservative full-potential equation is solved by a time-accurate approximate factorization algorithm and internal Newton iterations. An integral boundary layer method based on the dissipation integral is used to account for viscous effects. The computational results about unsteady transonic forces on wings, bodies and control surfaces are in agreement with experimental data.
文摘This article is the written version of a lecture given at the Festkolloquium on the occasion of Prof. Dr.-Ing. Dr.techn. E.h. Jtirgen Zierep＇s 80th birthday held at the Universitat Karlsruhe, 21 January 2009. It deals with laminar viscous inviscid interactions in transonic narrow channel flows. Special emphasis is placed on the internal structure of pseudo-shocks and properties of nozzle flows. Also, it is shown that the theory, first formulated for perfect gases, can easily be extended to the case of general single phase fluids.
文摘A quasi-simultaneous viscous/inviscid interaction model and a new integral method are tried to predict twodimensional incompressible turbulent boundary-layer separating flows. The results are compared with experiments and other prediction.
文摘To compute transonic flows over a complex 3D aircraft configuration, a viscous/inviscid interaction method is developed by coupling an integral boundary-layer solver with an Eluer solver in a ＂semi-inverse＂ manner. For the turbulent boundary-layer, an integral method using Green＇s lag equation is coupled with the outer inviscid flow. A blowing velocity approach is used to simulate the displacement effects of the boundary layer. To predict the aerodynamic drag, it is developed a numerical technique called far-field method that is based on the momentum theorem, in which the total drag is divided into three component drags, i.e. viscous, induced and wave-formed. Consequently, it can provide more physical insight into the drag sources than the often-used surface integral technique. The drag decomposition can be achieved with help of the second law of thermodynamics, which implies that entropy increases and total pressure decreases only across shock wave along a streamline of an inviscid non-isentropic flow. This method has been applied to the DLR-F4 wing/body configuration showing results in good agreement with the wind tunnel data.
