Through-flow model for design and analysis integrated in a three-dimensional navier-stodkes solver

摘要

A multiblock, multigrid Navier-Stokes solver has been extended to include a through-flow model for the design and analysis of turbomachines. The presentce of the blades in the inviscid axisymmetric flow is modelled in the classical way through a distrubted blade force to produce the desired turning, a blockage factor that accounts for the reduced area due to blade thickness, and a distributed friction force representing the entropy increase due to viscous stresses and heat conduction. The exact blade geometry is not required. All features of the 3D code concerning the physical fluid model, boundary conditions, spatial and time discretization, convergence acceleration techniques, and data visualization are availabe to the through-flow module. This includes the capability ot treat the entire range of relevant Mach numbers, from strictly incompressible (through a preconditioning technique) to supersonic, as well as any number of blade rows in any configuration, including, e.g., bypass engines. Selected elements comprising the through-flow module. This includes the capability to treat the entire range of relevant Mach numbers, from strictly incompressible (through a preconditioning technique) to supersonic, as well as any number of blade rows in any configuration, including, e.g., bypass engines. Selected elements comprising the through-flow model are discussed, with special emphasis on the blade force and its discretization. The properties of analysis and design mode with respect to shocks and the associated loasses are investigated. The methodology is demonstrated on a transonic compressor rotor and a four-stage low speed turbine.