Comparison Of Starting Performance Of Several Typical Inward Turning Inlets

Inlet determines airflow catching and compression of a scramjet,and its integration with precursor design determines the shape of the hypersonic.Comparing to the two-dimension or sidewall compression inlet,inward turning inlet has better performance.Currently It becomes the focus of the hypersonic flight vehicle development.Starting from the design method,to study and contrast in several typical the starting,performance and the characteristics of the flow field of inlet contraction.are important.Nowadays the study is focused on the base-flow field of inlet in the design,inlet performance and flow field structure,cross section fusion of the geometry and so on.In this paper,firstly selecting the inverted conical flow field inside the nozzle,secondly a given export shape and Mach number,shock wave Angle,heat ratio,Mach number,thirdly using the streamline tracking technology and the method of cross section fusion,last successfully design the asymmetric circular exports inlet,offset circular export inlet and REST inlet.Designing process includes four parts:solution of the flow field physical information,streamline solution of the flow field,through the flow geometry data modeling,viscosity correction and numerical simulation validation.After completing the inlet design,the performance of the inlet under the design conditions is compared.Performance comparison on the inlet total pressure recovery coefficient,pressure ratio,temperature ratio,compression efficiency,kinetic energy efficiency,and exit Mach number,etc.It is obtained that three types of inlet parameters in the design with the same circumstances,the difference of all kinds of performance parameters is not big,the obvious difference is reflected in different flow field structures.In this paper,varying Mach number of the flow makes the inlets from the design conditions to upstart state.Then analyses of the sensitivity of the three kinds of inward turning inlet are carried out changing Mach number.The flow field structure is observed in the flow separation,secondary flow and outlet flow field uniformity.It shows in the intensity and position of vortex structure changing and the mainstream at export changing.The best flow field uniformity is axially symmetric circular exports inlets.Less sensitive to Mach number is offset circular exports inlet.The capture ability of REST inlet is the best.