Advanced civil aero-engines tend to adopt lean burn combustors to meet emission requirements.The exit of a lean burn combustor experiences highly non-uniformities in both temperature(Hot Streak,HS)and flow(swirl).This...Advanced civil aero-engines tend to adopt lean burn combustors to meet emission requirements.The exit of a lean burn combustor experiences highly non-uniformities in both temperature(Hot Streak,HS)and flow(swirl).This paper presents a numerical investigation on the behaviors of a High-Pressure(HP)turbine under a combined effect of swirl and hot streak.The investigation was conducted on a GE-E3 HP turbine with unsteady numerical simulations,which considered the realistic clocking position of the HP Nozzle Guide Vane(NGV)relative to the combustor.The influences of swirl orientations on the HS migration and thermal performances on the blade surface were examined.Results indicate that,inside the NGV passage,the swirl’s induced incidence angle effect dominates the HS radial migration.The transversal movement of HS follows the cross flow and thus makes itself approach the Suction Side(SS)and keep away from the Pressure Side(PS)as passing through the NGV,so that HS near the SS is more influenced by the incidence angle effect than that near the PS.As for the heat transfer,swirl affects the Heat Transfer Coefficient(HTC)on the NGV’s PS and SS mainly through the incidence angle effect.Different from the NGV,the inlet swirl and HS have limited effect on the HTC on the rotor blade’s PS,while on the rotor blade’s SS,the original vortex system dominates;therefore,the inlet non-uniformities merely enhance the HTC on the SS rather than alter its distribution characteristics.展开更多
Deeply research on management and application of hot streak is an important way to breakthrough technique obstacle of aero engine hot components.Numerical method is a useful instrument to investigate the correlative p...Deeply research on management and application of hot streak is an important way to breakthrough technique obstacle of aero engine hot components.Numerical method is a useful instrument to investigate the correlative problems.Firstly the paper developed independently three dimensional unsteady parallel computational code-MpiTurbo based on Fortran 90 and MPI at Linux operating system.Then unsteady numerical simulation was carried out to investigate impacts of the factors,which included circumferential locations of hot streak and clocking positions of blade rows,on the thermal environment of a 1+1 counter-rotating turbine.The results clearly indicated that clocking positions of hot streak/blade row and blade row/blade row had great influence on the time-averaged temperature distribution of the third blade row.Therefore,it can be effective for improving thermal environment of turbine to optimize blade parameters and clocking positions.Lastly film cooling layout was designed by the repetitious steady simulation based on source term method.And the flow structure detail was given by the unsteady simulation.展开更多
Three-dimensional,viscous,and unsteady CFD simulations have been performed in order to reveal the influencing factors of hot streaks migration in high pressure stage of a vaneless counter-rotating turbine. Based on th...Three-dimensional,viscous,and unsteady CFD simulations have been performed in order to reveal the influencing factors of hot streaks migration in high pressure stage of a vaneless counter-rotating turbine. Based on the numerical results,the comparison between the case with inlet hot streaks and case without inlet hot streaks is carried out,which shows that the effect of inlet hot streaks on the load distributions of high pressure turbine airfoils is not notable and the airfoil load distributions are directly related to the inlet pressure distributions. The predicted results also indicate that the circumferential and radial movements of the hot streaks were not observed in the high pressure turbine stator. This means that the combined effects of secondary flow and buoyancy are very weak in the high pres-sure turbine stator. The numerical results also prove that the circumferential flow angle effect at the inlet of the high pressure turbine rotor,secondary flow effect and buoyancy effect are the mainly influencing factors to directly affect the migration characteristics of the hot streaks in the high pressure turbine rotor.展开更多
The temperature of flow at the combustor exit is inherently non-uniform and the hot fluid is called hot-streak. An in-house CFD software, NUAA-Turbo, was used to carry out 3D unsteady simulations on the PW-Esingle-sta...The temperature of flow at the combustor exit is inherently non-uniform and the hot fluid is called hot-streak. An in-house CFD software, NUAA-Turbo, was used to carry out 3D unsteady simulations on the PW-Esingle-stage high-pressure turbine. The hot-streak effect based on real stator and combustor counts was approximately evaluated by the contraction/dilatation method on the interface. The unsteady attenuation and migration process of hot-streaks in the turbine passage were well captured. The general performance parameters for different circumferential positions of hot-streaks were relatively consistent. Then, the influences of hot-streaks on blade surface temperature were investigated by comparing results under hot-streak and uniform inflow conditions. Unsteady simulations with combined inlet hot-streak and swirling flow show that the core of a hot-streak migrates to the tip under the influence of a positive swirl, while the phenomenon is just opposite with a negative swirl. Therefore, the heat transfer environment of rotor blades shows great differences with different directions of inlet swirl.展开更多
基金funded by the National Science Foundation of China(No.61890923)the National Science and Technology Major Project,China(No.J2019-VIII-0001-0162).
文摘Advanced civil aero-engines tend to adopt lean burn combustors to meet emission requirements.The exit of a lean burn combustor experiences highly non-uniformities in both temperature(Hot Streak,HS)and flow(swirl).This paper presents a numerical investigation on the behaviors of a High-Pressure(HP)turbine under a combined effect of swirl and hot streak.The investigation was conducted on a GE-E3 HP turbine with unsteady numerical simulations,which considered the realistic clocking position of the HP Nozzle Guide Vane(NGV)relative to the combustor.The influences of swirl orientations on the HS migration and thermal performances on the blade surface were examined.Results indicate that,inside the NGV passage,the swirl’s induced incidence angle effect dominates the HS radial migration.The transversal movement of HS follows the cross flow and thus makes itself approach the Suction Side(SS)and keep away from the Pressure Side(PS)as passing through the NGV,so that HS near the SS is more influenced by the incidence angle effect than that near the PS.As for the heat transfer,swirl affects the Heat Transfer Coefficient(HTC)on the NGV’s PS and SS mainly through the incidence angle effect.Different from the NGV,the inlet swirl and HS have limited effect on the HTC on the rotor blade’s PS,while on the rotor blade’s SS,the original vortex system dominates;therefore,the inlet non-uniformities merely enhance the HTC on the SS rather than alter its distribution characteristics.
基金the financial support by the National High Technology R&D Project of China (No.2006AA05A104)
文摘Deeply research on management and application of hot streak is an important way to breakthrough technique obstacle of aero engine hot components.Numerical method is a useful instrument to investigate the correlative problems.Firstly the paper developed independently three dimensional unsteady parallel computational code-MpiTurbo based on Fortran 90 and MPI at Linux operating system.Then unsteady numerical simulation was carried out to investigate impacts of the factors,which included circumferential locations of hot streak and clocking positions of blade rows,on the thermal environment of a 1+1 counter-rotating turbine.The results clearly indicated that clocking positions of hot streak/blade row and blade row/blade row had great influence on the time-averaged temperature distribution of the third blade row.Therefore,it can be effective for improving thermal environment of turbine to optimize blade parameters and clocking positions.Lastly film cooling layout was designed by the repetitious steady simulation based on source term method.And the flow structure detail was given by the unsteady simulation.
文摘Three-dimensional,viscous,and unsteady CFD simulations have been performed in order to reveal the influencing factors of hot streaks migration in high pressure stage of a vaneless counter-rotating turbine. Based on the numerical results,the comparison between the case with inlet hot streaks and case without inlet hot streaks is carried out,which shows that the effect of inlet hot streaks on the load distributions of high pressure turbine airfoils is not notable and the airfoil load distributions are directly related to the inlet pressure distributions. The predicted results also indicate that the circumferential and radial movements of the hot streaks were not observed in the high pressure turbine stator. This means that the combined effects of secondary flow and buoyancy are very weak in the high pres-sure turbine stator. The numerical results also prove that the circumferential flow angle effect at the inlet of the high pressure turbine rotor,secondary flow effect and buoyancy effect are the mainly influencing factors to directly affect the migration characteristics of the hot streaks in the high pressure turbine rotor.
基金supported by the AECC Shenyang Engine Research Institute of China
文摘The temperature of flow at the combustor exit is inherently non-uniform and the hot fluid is called hot-streak. An in-house CFD software, NUAA-Turbo, was used to carry out 3D unsteady simulations on the PW-Esingle-stage high-pressure turbine. The hot-streak effect based on real stator and combustor counts was approximately evaluated by the contraction/dilatation method on the interface. The unsteady attenuation and migration process of hot-streaks in the turbine passage were well captured. The general performance parameters for different circumferential positions of hot-streaks were relatively consistent. Then, the influences of hot-streaks on blade surface temperature were investigated by comparing results under hot-streak and uniform inflow conditions. Unsteady simulations with combined inlet hot-streak and swirling flow show that the core of a hot-streak migrates to the tip under the influence of a positive swirl, while the phenomenon is just opposite with a negative swirl. Therefore, the heat transfer environment of rotor blades shows great differences with different directions of inlet swirl.
