An Off Design Shock Capturing Finite Difference Approach for Caret Waverider Configurations.

摘要

The three dimensional off design flow fields are calculated for stream Mach numbers in the range 1.3 tgo 4.0 and corresponding to attached and detached shocks at the leading edges of a reentrant pyramidal waverider geometry. The MacCormack shock capturing version of the Lax-Wendroff finite difference technique is used with grids chosen to align with surface, symmetry and approximate shock traces in the transverse plane. Separate natural grid systems are defined for the compression and expansion regions, and an alternating region algorithm is used in combination with a sequential transfer of the edge region boundary conditions. The latter are derived from overlapping portions of the computational grids as integration proceeds axially to an asymptotic conical field. Equivalent attached shock cases result from either of two approaches: the alternating region algorithm, or a consideration of solely the compression region with uniform unknown conditions assumed near the edges. For detached shock cases overall lift and drag coefficients exhibit smooth variations between the attached edge and detached apex limits. (Author)