What is curved compression? In short words, it is a compression mode under which all compression surfaces participate in compressing supersonic flow. It is a compression mode under which flow is compressed on “every inch of compression surface”. Curved compression is usually accompanied by curved shock wave.
According to research, curved compression system has advantages in reducing total-pressure loss, shortening compression length, avoiding boundary layer separation, improving non-design point performance, reducing drag, tolerating non-uniform coming flow. Therefore, curved compression inlet gradually draws attention, explorations and detailed researches have been carried out for design method, performance and application of such flow field, and rich achievements have been made.
There are two kind of inverse design methods. The design idea and process of the first kind of inverse design are introduced, namely design for the whole compression surface based on existing flow parameter distribution. The focus of flow field design is the design of one or more curved shock waves and obviously the solution is not unique.
The second kind of inverse design is introduced, namely design for compression surface shape and the whole compression flow field based on the specified pressure distribution on compression surface or design for geometric shape of compression surface and the whole curved shock wave compression flow field based on the specified compression surface deceleration rule.
With the increasing inward turning inlet research, design of axisymmetric reference flow field has become a key problem. The process and details of designing axisymmetric reference flow field with inverse tangent pressure rising rule of wall, inverse tangent decelerating rule of wall and other method by fully using the second kind of inverse design method are introduced. A new method is provided for designing excellent-performance inward turning inlet.
The design processes, model experiments and partial experiment results of these inlets for design of hypersonic two dimensional inlet, hypersonic axisymmetric inlet, hypersonic sidewall compression inlet and hypersonic inward turning inlet with the inverse design methods, are introduced.
In order to adapt to the needs in wide Mach number working range, both the concept of curved shock wave curved compression surface and concept of adaptive variable geometric elastic curved compression surface are proposed. The performance advantages and future development of this new design concept are discussed.
