The results of experimental investigation of laminar-turbulent transition in three-dimensional flow under the high continuous pressure gradient including the flow with local boundary layer separation are presented. Th...The results of experimental investigation of laminar-turbulent transition in three-dimensional flow under the high continuous pressure gradient including the flow with local boundary layer separation are presented. The experimental studies were performed within the Mach number range from 4 to 6 and Reynolds number 10-60×106 1/m, the angles of attack were 0° and 5°. The experiments were carried out on the three-dimensional convergent inlet model with and without sidewalls. The influence of artificial tubulator of boundary layer on transition and flow structure was studied. The conducted researches have shown that adverse pressure gradient increase hastens transition and leads to decrease of transition area length. If pressure gradient rises velocity profile fullness increases and profile transformation from laminar to turbulent occurs. As a result of it the decrease of separation area length occurs. The same effect was reached with Reynolds number increase. These results are compared with the data on two-dimensional model with longitudinal curvature.展开更多
The paper describes the results of the electron-beam initiation of the combustion in the mixtures of hydrogen,natural gas or kerosene vapors with air.Electron beam characteristics were studied in closed volume with im...The paper describes the results of the electron-beam initiation of the combustion in the mixtures of hydrogen,natural gas or kerosene vapors with air.Electron beam characteristics were studied in closed volume with immobile gas.The researches included definition of an integrated current of an electronic beam,distribution of a current density and an estimation of average energy of electrons.Possibility of fuel mixtures ignition by means of this approach in the combustor at high velocity at the entrance was demonstrated.Experiments were carried out at Mach numbers of 4 and 5.Process of ignition and combustion under electron beam action was researched.It was revealed that ignition of mixture occurs after completion of electron gun operation.Data obtained have confirmed effectiveness of electron beam application for ignition of hydrogen and natural gas.The numerical simulation of the combustion of mixture in channel was carried out by means of ANSYS CFD 12.0 instrumentation on the basis of Reynolds averaged Navier-Stokes equation using SST/k-ωturbulence model.For combustion modeling,a detailed kinetic scheme with 38 reactions of 8 species was implemented taking into account finite rate chemistry.Computations have shown that the developed model allow to predict ignition of a mixture and flame propagation even at low flow temperatures.展开更多
文摘The results of experimental investigation of laminar-turbulent transition in three-dimensional flow under the high continuous pressure gradient including the flow with local boundary layer separation are presented. The experimental studies were performed within the Mach number range from 4 to 6 and Reynolds number 10-60×106 1/m, the angles of attack were 0° and 5°. The experiments were carried out on the three-dimensional convergent inlet model with and without sidewalls. The influence of artificial tubulator of boundary layer on transition and flow structure was studied. The conducted researches have shown that adverse pressure gradient increase hastens transition and leads to decrease of transition area length. If pressure gradient rises velocity profile fullness increases and profile transformation from laminar to turbulent occurs. As a result of it the decrease of separation area length occurs. The same effect was reached with Reynolds number increase. These results are compared with the data on two-dimensional model with longitudinal curvature.
基金supported by the Russian Foundation for Basic Research(Grant No.13-08-00786-a)
文摘The paper describes the results of the electron-beam initiation of the combustion in the mixtures of hydrogen,natural gas or kerosene vapors with air.Electron beam characteristics were studied in closed volume with immobile gas.The researches included definition of an integrated current of an electronic beam,distribution of a current density and an estimation of average energy of electrons.Possibility of fuel mixtures ignition by means of this approach in the combustor at high velocity at the entrance was demonstrated.Experiments were carried out at Mach numbers of 4 and 5.Process of ignition and combustion under electron beam action was researched.It was revealed that ignition of mixture occurs after completion of electron gun operation.Data obtained have confirmed effectiveness of electron beam application for ignition of hydrogen and natural gas.The numerical simulation of the combustion of mixture in channel was carried out by means of ANSYS CFD 12.0 instrumentation on the basis of Reynolds averaged Navier-Stokes equation using SST/k-ωturbulence model.For combustion modeling,a detailed kinetic scheme with 38 reactions of 8 species was implemented taking into account finite rate chemistry.Computations have shown that the developed model allow to predict ignition of a mixture and flame propagation even at low flow temperatures.
