Rapid Estimation And Large-Eddy Simulation Of Curved Shock-Compressed Supersonic/Hypersonic Inlet Flow-field

This dissertation explores the inverse design and flow-field rapid estimation method,and carries out large-eddy simulation to investigate the typical flows at the supersonic inlet shoulder.First,a package with functions of inverse design and flow-field rapid estimation is developed.The curved shocks are used for compression.After inviscid simulation on the design model,we find that wall pressure distribution and shock details obtained from inviscid CFD agree well with the designing condition.Inlet performance and wave structures obtained from flow-field rapid estimation function differ from results of CFD within a considerable ratio.In the design of the solid-fuel ramjet inlets,the inlet performance improves significantly with the rise of CRI.The choices of the throat constant area length and outlet area are results of balance between the total pressure recovery coefficient and critical pressure.Second,a large-eddy simulation method for supersonic internal flows is developed in the framework of OpenFOAM library.Large-eddy simulation on a supersonic flat plate is carried out to validate the method.The results show that computed mean velocity profile and fluctuating velocity profile agree well with the DNS results,the skin friction coefficient distribution and anisotropy profile are consistent with the proposed theories.Next,large-eddy simulations on a successively expanding supersonic boundary layer are conducted.Air injections are introduced into the boundary layer to control the relaminarizaion.Results show that as the boundary layer expands,the number of large scale turbulent structures reduced;the skin friction coefficient decreases drastically after a local rise;the outer boundary layer accelerates while the inner boundary layer decelerates;the shape factor grows and the boundary layer is more likely to separate;TKE drops significantly,especially in the inner layer.After introducing the air injection,phenomena above are all controlled.The flow control effectively suppresses the relaminarization.Last,large-eddy simulations of the shock wave/boundary layer interaction at the shoulder are carried out.The same air injection is introduced to the flow-field.Results show that the shock excites the rise of TKE in the boundary layer,large scale structures occur in the expansion region;The incident shock is observed to be unsteady in the span-wise direction;When turbulent structures encounter the incident shock,the shock deforms locally;the rise of the fluctuating wall temperature delays in stream-wise direction comparing to the fluctuating wall pressure;After introducing the air injection,the separation bubble grows in the wall-normal direction,and influences on the injection shape,which leads to the deterioration of the upstream separation;overall,the injection results in the increase of turbulent intensity.However,the injection failed to control the separation.Injection parameters need further modification.