A wavecatcher type scramjet intake,that reduces the Mach number number from 4 to 1.552,is used as the basis for a study of flow starting/unstarting as affected by freestream angles of attack and sideslip.The intake de...A wavecatcher type scramjet intake,that reduces the Mach number number from 4 to 1.552,is used as the basis for a study of flow starting/unstarting as affected by freestream angles of attack and sideslip.The intake design is based on a morphed streamtube consisting of two conical flow streamlines using streamline tracing and osculating axisymmetric design theory.Intake flow and performance is modeled using the numerical CFD code and the k-e turbulence model.The intake unstarts at a sideslip angle of 2,a positive angle of attack of 1.Both positive angle of attack and sideslip angle have an adverse effect on the startability of the MBus intake.At negative angles,the intake initially unstarts at5angle of attack,due to the thickened shear layer induced by the streamwise vortex.Then it re-starts at8angle of attack,mainly due to the expansion fan formed at the leading edge,causing the shock wave structures inside the intake to be reestablished.展开更多
Wavecatcher(inward-turning)intake flows,at design Mach 12,are investigated numerically,to display the effect of wall temperature on flow structures and intake performance.Hypersonic experiments on shock wave/boundary ...Wavecatcher(inward-turning)intake flows,at design Mach 12,are investigated numerically,to display the effect of wall temperature on flow structures and intake performance.Hypersonic experiments on shock wave/boundary layer interaction are used to validate the Spalart-Allmaras turbulence model for reproducing the features of hypersonic flow.Simulations of hypersonic intake flow are performed at different wall temperatures,including isothermal T_(w)Z 300 K,T_(w)Z 1000 K,T_(w)Z 2000 K,and the adiabatic case.The shock structures,impinging shock positions,surface streamlines,and the development of internal streamwise vortices are discussed.The mass-averaged performance of intake flow shows that,when the wall temperature changes from T_(w)Z 300 K to adiabatic,the mass capture coefficient decreases from 0.991 to 0.933,the total pressure recovery decreases from 0.200 to 0.083,while exit section Mach number decreases from 4.478 to 3.514.The results suggest that the osculating design method of wavecatcher intake design can successfully be extended to Mach 12,while capturing all airflow at isothermal wall conditions.展开更多
基金National Natural Science Foundation of China(No.:12002261)National Postdoctoral Program for Innovative Talents of China(No.:BX20200267)+2 种基金Young Talent fund of University Association for Science and Technology in Shaanxi of China(No.:20200501)China Postdoctoral Science Foundation(No.:2020M673411)the Fundamental Research Funds for the Central Universities of China(No.:xzy012020096).G.Chen are grateful for the support of National Natural Science Foundation of China(No.:11872293).
文摘A wavecatcher type scramjet intake,that reduces the Mach number number from 4 to 1.552,is used as the basis for a study of flow starting/unstarting as affected by freestream angles of attack and sideslip.The intake design is based on a morphed streamtube consisting of two conical flow streamlines using streamline tracing and osculating axisymmetric design theory.Intake flow and performance is modeled using the numerical CFD code and the k-e turbulence model.The intake unstarts at a sideslip angle of 2,a positive angle of attack of 1.Both positive angle of attack and sideslip angle have an adverse effect on the startability of the MBus intake.At negative angles,the intake initially unstarts at5angle of attack,due to the thickened shear layer induced by the streamwise vortex.Then it re-starts at8angle of attack,mainly due to the expansion fan formed at the leading edge,causing the shock wave structures inside the intake to be reestablished.
基金the support of the National Natural Science Foundation of China(No.12002261)National Postdoctoral Program for Innovative Talents,China(No.BX20200267)+1 种基金The Young Talent Fund of University Association for Science and Technology in Shaanxi,China(No.20200501)China Postdoctoral Science Foundation(No.2020M673411).
文摘Wavecatcher(inward-turning)intake flows,at design Mach 12,are investigated numerically,to display the effect of wall temperature on flow structures and intake performance.Hypersonic experiments on shock wave/boundary layer interaction are used to validate the Spalart-Allmaras turbulence model for reproducing the features of hypersonic flow.Simulations of hypersonic intake flow are performed at different wall temperatures,including isothermal T_(w)Z 300 K,T_(w)Z 1000 K,T_(w)Z 2000 K,and the adiabatic case.The shock structures,impinging shock positions,surface streamlines,and the development of internal streamwise vortices are discussed.The mass-averaged performance of intake flow shows that,when the wall temperature changes from T_(w)Z 300 K to adiabatic,the mass capture coefficient decreases from 0.991 to 0.933,the total pressure recovery decreases from 0.200 to 0.083,while exit section Mach number decreases from 4.478 to 3.514.The results suggest that the osculating design method of wavecatcher intake design can successfully be extended to Mach 12,while capturing all airflow at isothermal wall conditions.
