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Abstract

This paper proposes a method of integration of internal and external flow called the dual waverider. A threedimensional shock structure is designed to simultaneously satisfy the theories of internal and external waveriders. By using the infinite radius of curvature and omnidirectional center of curvature of a planar shock wave, external flows are made to transition smoothly to internal flows in the cross section. Moreover, a compression efficiency factor (CEF) is proposed to integrate internal and external flows in sections along the flow. Different values of the CEF represent internal/planar/external flows. An integration methodology for the dual waverider is then proposed by combining the two flows. By using this design, various structures of the dual waverider are obtained for different conditions. The theory of the dual waverider is also improved to develop one with double internal passages. Three-dimensional numerical simulations were performed on different configurations of the dual waverider to verify the correctness of the proposed design. The results showed good agreement with those obtained during the design process. Research on the aerodynamic characteristics of the configuration indicates that the dual waverider can integrate internal and external flows and can maintain a high lift-to-drag ratio.

Mach reflection (MR) is an essential component in the development of shock theory, as the incident shock curvature is found to have a significant effect on the MR patterns. Curved-shock Mach reflection (CMR) is not yet adequately understood due to the rotational complexity behind curved shocks. Here, CMR in steady, planar/axisymmetric flows is analyzed to supplement the well-studied phenomena caused by oblique-shock Mach reflection (OMR). The solution from von Neumann's three-shock theory does not fully describe the CMR case. A CMR structure is presented, characterized by an incident shock, reflected shock, Mach stem, and expansion/compression waves over the slipline, or occasionally an absence of waves due to pressure equilibrium. On the basis of this CMR structure, an analytical model for predicting the Mach stem in the CMR case is established. The model reduces to the OMR case if the shock curvature is not applicable. Predictions of the Mach stem geometry and shock structure based on the model exhibit better agreement with the numerical results than predictions using previous models. It is found that the circumferential shock curvature plays a key role in the axisymmetric doubly curved CMR case, which results in a different outcome from the planar case.

In practical aerodynamic problems, curved shock/boundary layer interaction (CSBLI) is more frequently encountered than the canonical SBLI. Owing to the topological complexity of the flow field brought about by shock curvature, accurate prediction of the interaction length scale of CSBLI is a challenging task. In this work, streamwise and spanwise curvatures are introduced in turn with the aim of establishing an analytical model for the interaction length scale of CSBLI based on conservation of mass. The validity and universality of the model are verified, which reveal the impact of the shock curvatures on the interaction, acting as the form of non-uniformity. The proposed method can be regarded as providing a foundation for further research on CSBLI, opening new perspectives for the investigation of SBLI flow structures.