High speed centrifugalcompressors are widely usedinindustry.Itisimportantto understanditsinternal flow fieldin orderto design higher efficiency and pressure ratio impellers.In this paper,a 3 Dviscous code to solve ...High speed centrifugalcompressors are widely usedinindustry.Itisimportantto understanditsinternal flow fieldin orderto design higher efficiency and pressure ratio impellers.In this paper,a 3 Dviscous code to solve the simplified Reynolds averaged Navier Stokes equations has been developed. The viscous effect is simulated by viscous bodyforce method.The governing equations are spatially discretizedinthe cell vortex finite volume scheme on a simple Hmesh.Theturbulence closureis made usingthe Baldwin Lomax model.This codeis demonstratedfor predictingtheinternalflow field of a high speed impeller.Some laser measured results are also illustratedfor comparing with calculated data.展开更多
The effect of bed thickness in rectangular fluidized beds is investigated through the CFD-DEM simula- tions of small-scale systems. Numerical results are compared for bubbling fluidized beds of various bed thicknesses...The effect of bed thickness in rectangular fluidized beds is investigated through the CFD-DEM simula- tions of small-scale systems. Numerical results are compared for bubbling fluidized beds of various bed thicknesses with respect to particle packing, bed expansion, bubble behavior, solids velocities, and par- ticle kinetic energy. Good two-dimensional （2D） flow behavior is observed in the bed having a thickness of up to 20 particle diameters. However, a strong three-dimensional （3D） flow behavior is observed in beds with a thickness of 40 particle diameters, indicating the transition from 2D flow to 3D flow within the range of 20-40 particle diameters. Comparison of velocity profiles near the walls and at the center of the bed shows significant impact of the front and back walls on the flow hydrodynamics of pseudo-2D fluidized beds. Hence, for quantitative comparison with experiments in pseudo-2D columns, the effect of walls has to be accounted for in numerical simulations.展开更多
This paper presentsthe concept ofafull function numerical methodforflow overa self excited vibrating body.It contains three dimensional (3 D) numerical analysis of unsteady aerodynamic force for a self excited ...This paper presentsthe concept ofafull function numerical methodforflow overa self excited vibrating body.It contains three dimensional (3 D) numerical analysis of unsteady aerodynamic force for a self excited vibrating body, calculation ofthe work done by unsteady aerodynamic force and damping, determination of the equilibrium amplitude and dynamic stress as wellas correspondinglife evaluation.展开更多
文摘High speed centrifugalcompressors are widely usedinindustry.Itisimportantto understanditsinternal flow fieldin orderto design higher efficiency and pressure ratio impellers.In this paper,a 3 Dviscous code to solve the simplified Reynolds averaged Navier Stokes equations has been developed. The viscous effect is simulated by viscous bodyforce method.The governing equations are spatially discretizedinthe cell vortex finite volume scheme on a simple Hmesh.Theturbulence closureis made usingthe Baldwin Lomax model.This codeis demonstratedfor predictingtheinternalflow field of a high speed impeller.Some laser measured results are also illustratedfor comparing with calculated data.
基金support of the National Energy Technology Laboratory’s ongoing research in advanced numerical simulation of multiphase flow under the RES contract DE-FE0004000
文摘The effect of bed thickness in rectangular fluidized beds is investigated through the CFD-DEM simula- tions of small-scale systems. Numerical results are compared for bubbling fluidized beds of various bed thicknesses with respect to particle packing, bed expansion, bubble behavior, solids velocities, and par- ticle kinetic energy. Good two-dimensional （2D） flow behavior is observed in the bed having a thickness of up to 20 particle diameters. However, a strong three-dimensional （3D） flow behavior is observed in beds with a thickness of 40 particle diameters, indicating the transition from 2D flow to 3D flow within the range of 20-40 particle diameters. Comparison of velocity profiles near the walls and at the center of the bed shows significant impact of the front and back walls on the flow hydrodynamics of pseudo-2D fluidized beds. Hence, for quantitative comparison with experiments in pseudo-2D columns, the effect of walls has to be accounted for in numerical simulations.
文摘This paper presentsthe concept ofafull function numerical methodforflow overa self excited vibrating body.It contains three dimensional (3 D) numerical analysis of unsteady aerodynamic force for a self excited vibrating body, calculation ofthe work done by unsteady aerodynamic force and damping, determination of the equilibrium amplitude and dynamic stress as wellas correspondinglife evaluation.
