Aerodynamic loads on a multi-bladed helicopter rotor in hovering flight were calculated by solving the three-dimensional incompressible Navier-Stokes equations. The rotor wake effects were accounted by the correction ...Aerodynamic loads on a multi-bladed helicopter rotor in hovering flight were calculated by solving the three-dimensional incompressible Navier-Stokes equations. The rotor wake effects were accounted by the correction of local geometric angle of attack according to a free-wake modeling in addition to an empirical modification for the tip flow effect. The validity and efficiency of the present method were verified by the comparisons between numerical results and experimental data.展开更多
Based on the demand on efficient axial-flow blast with low noise and energy saving, a blade was designed through the application of the unequal work distribution principle and the exponential twisted camber was used t...Based on the demand on efficient axial-flow blast with low noise and energy saving, a blade was designed through the application of the unequal work distribution principle and the exponential twisted camber was used to shape blades. Then, the hydrodynamic characteristics of blades were studied and the strengths and vibrations of blades and hydro-dynamic noise of blast were analyzed. Furthermore, the software of optimization design of axial-flow blast was developed. Finally, the HMF-T40No.20 axial-flow blast used in large textile conditioner system of cotton spinning industry was designed, which could meet the required total safety and environmental requirements as the corresponding test demonstrates. The study is beneficial to designing axial-flow blast.展开更多
Method of optimal hydraulic design and CAD application of runner blades of axial-flow hydraulic turbines are discussed on the basis of optimization principle and CAD technique in this paper. Based on the theory of flu...Method of optimal hydraulic design and CAD application of runner blades of axial-flow hydraulic turbines are discussed on the basis of optimization principle and CAD technique in this paper. Based on the theory of fluid dynamics, the blade's main geometrical parameter, working parameters and performances index of the blades and the relationship between them are analysed, and the mathematical model of optimal hydraulic design of axial-flow runners has been established. Through nonlinear programming, the problems can be solved. By making use of the calculation geometry and computer graphics, the distribution method of the singular points, and an CAD applied software, an optimal hydraulic design are presented.展开更多
An optimization method to design turbine airfoils using a Genetic Algorithm (GA) design shell coupled directly with a viscous CFD (Computational Fluid Dynamics) analysis code is proposed in this paper. The blade geome...An optimization method to design turbine airfoils using a Genetic Algorithm (GA) design shell coupled directly with a viscous CFD (Computational Fluid Dynamics) analysis code is proposed in this paper. The blade geometry is parameterized and the optimization method is used to search for a blade geometry that will minimize the loss in the turbine cascade passage. The viscous flow prediction code is verified by the experimental data of cascade, which is typical for a gas turbine rotor blade section. A comparative study of the blades designed by the optimization technique and the original one is presented[展开更多
文摘Aerodynamic loads on a multi-bladed helicopter rotor in hovering flight were calculated by solving the three-dimensional incompressible Navier-Stokes equations. The rotor wake effects were accounted by the correction of local geometric angle of attack according to a free-wake modeling in addition to an empirical modification for the tip flow effect. The validity and efficiency of the present method were verified by the comparisons between numerical results and experimental data.
文摘Based on the demand on efficient axial-flow blast with low noise and energy saving, a blade was designed through the application of the unequal work distribution principle and the exponential twisted camber was used to shape blades. Then, the hydrodynamic characteristics of blades were studied and the strengths and vibrations of blades and hydro-dynamic noise of blast were analyzed. Furthermore, the software of optimization design of axial-flow blast was developed. Finally, the HMF-T40No.20 axial-flow blast used in large textile conditioner system of cotton spinning industry was designed, which could meet the required total safety and environmental requirements as the corresponding test demonstrates. The study is beneficial to designing axial-flow blast.
文摘Method of optimal hydraulic design and CAD application of runner blades of axial-flow hydraulic turbines are discussed on the basis of optimization principle and CAD technique in this paper. Based on the theory of fluid dynamics, the blade's main geometrical parameter, working parameters and performances index of the blades and the relationship between them are analysed, and the mathematical model of optimal hydraulic design of axial-flow runners has been established. Through nonlinear programming, the problems can be solved. By making use of the calculation geometry and computer graphics, the distribution method of the singular points, and an CAD applied software, an optimal hydraulic design are presented.
文摘An optimization method to design turbine airfoils using a Genetic Algorithm (GA) design shell coupled directly with a viscous CFD (Computational Fluid Dynamics) analysis code is proposed in this paper. The blade geometry is parameterized and the optimization method is used to search for a blade geometry that will minimize the loss in the turbine cascade passage. The viscous flow prediction code is verified by the experimental data of cascade, which is typical for a gas turbine rotor blade section. A comparative study of the blades designed by the optimization technique and the original one is presented[
