Three-dimensional numerical computation of the flow fields and pumping performances for the lobed mixer-ejector are conducted using full Navier-Stokes equations. In the computation, the inlet of the primary flow uses ...Three-dimensional numerical computation of the flow fields and pumping performances for the lobed mixer-ejector are conducted using full Navier-Stokes equations. In the computation, the inlet of the primary flow uses the mass flowrate boundary condition. The inlet of the second flow and the outlet of the mixing flow use the pressure boundary condition. Compared with the relative experimental resuits, it is shown that the present calculation is reasonable. And a series of numerical studies is performed to obtain the effects of area ratio and length-to-diameter ratio of mixing duct on pumping coefficient and thermal mixing efficiency of a lobed mixer-ejector.展开更多
The co-located grid, SIMPLEC and Chen-Kim modified k - E turbulence model are applied to investigate numerically the multi-stream flow and temperature fields in the complex channel with a forced mixer lobe at room tem...The co-located grid, SIMPLEC and Chen-Kim modified k - E turbulence model are applied to investigate numerically the multi-stream flow and temperature fields in the complex channel with a forced mixer lobe at room temperature and at elevated temperature. The body-fitted coordinate grids are generated respectively in sub-domains according to the shapes of the channel by solving Poisson’s equations to compose the whole grid of the domain. The large viscosity, linear and simultaneous under-relaxation factors are used to solve the coupling of fluid and solid. The solid grid is complemented at the upper inlet of the secondary flow to keep the same node number at the inlet and at double-wall sub-domains. The numerical results and experimental data show good agreement at room temperature. It is illustrated that the cooling air ejected into the slot between the double plates decreases the temperature of the wall.展开更多
文摘Three-dimensional numerical computation of the flow fields and pumping performances for the lobed mixer-ejector are conducted using full Navier-Stokes equations. In the computation, the inlet of the primary flow uses the mass flowrate boundary condition. The inlet of the second flow and the outlet of the mixing flow use the pressure boundary condition. Compared with the relative experimental resuits, it is shown that the present calculation is reasonable. And a series of numerical studies is performed to obtain the effects of area ratio and length-to-diameter ratio of mixing duct on pumping coefficient and thermal mixing efficiency of a lobed mixer-ejector.
文摘The co-located grid, SIMPLEC and Chen-Kim modified k - E turbulence model are applied to investigate numerically the multi-stream flow and temperature fields in the complex channel with a forced mixer lobe at room temperature and at elevated temperature. The body-fitted coordinate grids are generated respectively in sub-domains according to the shapes of the channel by solving Poisson’s equations to compose the whole grid of the domain. The large viscosity, linear and simultaneous under-relaxation factors are used to solve the coupling of fluid and solid. The solid grid is complemented at the upper inlet of the secondary flow to keep the same node number at the inlet and at double-wall sub-domains. The numerical results and experimental data show good agreement at room temperature. It is illustrated that the cooling air ejected into the slot between the double plates decreases the temperature of the wall.
