Design methodology of axisymmetric variable geometry inlet

Cone cavity flow was investigated with computational fluid dynamics(CFD) method.The flow structure and total pressure distribution were compared with experimental data.Results indicate that numerical results are in accordance with experimental data and the CFD method is creditable.Cone cavities with different shapes under various inflow conditions were studied;the coupling characteristic of cone cavity flow was analyzed and the flow phenomena downstream the cavity which were affected by cone cavity was presented.A kind of axisymmetric variable geometry inlet with movable cone tip was designed and its aerodynamic performances were compared with that of the relevant fixed geometry inlets.Results show that by translating cone tip backward toward the centerbody of the inlet,the exterior compression waves can be modulated and mass flow rate is obtainable above 0.99 when inflow Mach number exceeds the design point.The variable geometry technique would lead to an evident increase of mass flow rate without changing the geometry of internal compression duct of inlet.