Research On Characteristics Of Curved Backswept Compression Corner Shock Wave/turbulent Boundary Layer Interactions

The curved backswept compression corner shock wave/turbulent boundary layer interactions between the compression shock wave of inward turning inlet and the boundary layer of the aircraft body,which will separate the front edge of the main compression of the inlet,induce secondary flow,and then develop the flow direction vortex is formed,resulting in low energy flow accumulation,and the outlet flow field distortion of the isolation section is large,so that the anti-pressure resistance of the inlet is weakened,the total pressure recovery coefficient of the outlet is lowered,the starting and restarting performance is lowered,and the inlet has many disadvantages influences.In view of this,this paper uses numerical simulation to study the curved backswept compression corner shock wave/turbulent boundary layer interactions.Firstly,the complex shock wave/turbulent boundary layer interactions problem in the inward turning inlet is abstracted and simplified into a curved backswept compression corner shock wave/turbulent boundary layer interactions model,and a one-sided uncoupled model and a two-sided coupled model are designed respectively.The one-side uncoupled model is numerically simulated.The results show that the shape of the separation zone formed by the one-side curved backswept compression corner shock wave/turbulent boundary layer interactions is curved,and the separation zone does not conform to the quasi-conical similarity,but the separation zone can be regarded as different by countless segments.The cone-shaped separation of the sweep angle is spliced together;the pressure change along the flow direction(X-direction)basically conforms to the compression corner pressure trend,but there is also a huge pressure gradient along the extension direction(Y-direction)of the curved swept compression corner;The comparison of the backswept compression corner shock/boundary layer interactions shows that the initial sweep angle of the curved swept compression corner has an important influence on the separation zone.Secondly,the parameterization of seven key parameters: Cone angle of basic flowfield,radius of basic flowfield,Mach number of basic flowfield design,capture line width,eccentricity of capture line,free flow Mach number,free flow boundary layer thickness,which are important to the influence of one-sided uncoupled interactions is extracted.The results show that the cone angle in the reference flow field increases and the separation area becomes larger.When the cone angle is too large,The improvement of pressure ratio from the reduction of the total pressure recovery coefficient is not obvious;the radius of the reference flow field is increased,and the compression capacity of the compressed surface flow is larger;the Mach number of the reference flow field design and the free-flow Mach number have no obvious influence on the separation area.Increasing the width of the capture line will result in an increase in the initial sweep angle and low energy flow accumulation.The comprehensive boost ratio and total pressure recovery are considered as two performance considerations.The selection of the eccentricity should be moderate,and it should not be too large or too small to be optimal;When the thickness of the boundary layer is increased,there is no significant change in the supercharging ratio,but it causes a significant change in the magnitude and position of the peak pressure along the span.Then,the numerical simulation of the two-sided coupled interference model is carried out under the condition that the key parameters are the same as the one-sided non-coupling.The results show that the separation zone formed by the bilateral coupled model is a symmetrical structure with a crescent shape.There is a significant pressure gradient along the exhibition direction.As the flow direction increases,the low energy flow accumulates at the center.Due to the coupling,the maximum value of the boundary layer separation zone is also increased by 51% compared with the uncoupled condition.The value position changes from y=-0.19 H to y=0 position.However,the influence range of the coupling effect is limited,and it is basically not affected by the coupling effect in the flow interval of the compression corner leading edge |y|(29)0.6H.Finally,the same key parameters as the one-sided non-coupling parameterization study are selected,and the influence law of key parameters is also studied for the two-sided coupled model.The results show that the influence of key parameters on the separation zone under the condition of bilateral coupling different from single-sided uncoupling,the double-sided coupling has the effect of“amplifying” effect;and the initial sweep angle has a more serious effect on the bilateral coupling.According to the parameterization study of the two-sided coupling model,according to the shape of the separation zone,the separation is divided into three categories: small separation state,crescent separation state and semi-circular separation state;key parameters and separation zone size are a function or two.The sub-function relationship,and this paper comprehensively sorts out a separation zone prediction formula.