Theory, Method, and Analysis of Waveriding-Dependent Area

In the aerodynamic shape design based on waveriders, the waverider surface is deemed to be unchangeable by default. It leads to many problems for practical application, such as in modifying the lower surface and adjusting the volume. In this paper, the concept of waveriding-dependent area (WDA) is proposed. The WDA represents the portion of waveriding surface, which decides the main shock wave. Employing the theory of characteristics, the method to generate the WDA is first to find a flow area on which the shock wave depends in inviscid axisymmetric supersonic flow. Then, taking this flow area as the basis flowfield, the wave riding surface generated by tracing streamlines is the so-called WDA. The range of WDA is analyzed using the oblique shock relations preliminarily. After that, computational fluid dynamics techniques were employed to test several osculating-cone configurations with retaining different ranges of waveriding surface. Their aerodynamic forces and longitudinal stabilities were compared, followed by the shock waves analysis in symmetric planes and trailing-edge sections. It is verified that just retaining WDA maintained the strength of the main shock wave, and thereby the shock waves attached along the leading edge, indicating evident waveriding performance. The WDA theory attempts to determine which area of the waverider surface is allowed to be modified or altered without breaking the waveriding performance. Hence, this concept is meaningful to enlarge loading volume, reduce drag, and improve wide-speed performance for practical waverider aircraft design.