Adapting Three-Dimensional Shock Control Bumps for Swept Flows

Abstract

Shock control bumps offer the potential to reduce wave drag on transonic aircraft wings. However, most studies to date have only considered unswept flow conditions, leaving uncertain their applicability to realistic finite swept wings. This paper uses a swept infinite-wing model as an intermediate step, and presents a computational study of the design drag performance of 3D bumps. A new geometric parameter, bump orientation, is introduced and found to be crucial to the performance under swept flows. Classic SCBs aligned approximately with the local to freestream flow direction can offer drag reductions comparable to those from similar but un-oriented devices in unswept flows, while badly misaligned bumps see severe performance degradation. For appropriately aligned classic bumps, the relationships between performance and selected geometric parameters (height, streamwise position and isolation) are found to be somewhat similar to those observed in unswept studies.

Quantitative comparison of 2D and 3D shock control bumps for drag reduction on transonic wings

“…Furthermore, 3D bumps also provide the possibility to generate streamwise vortices [15][16][17], which are beneficial for improving the off-design performances, such as buffet alleviation, investigated by Eastwood and Jarrett [18]. Recently, Jones et al [19] investigated the effects of swept flows for 3D bumps, and a new geometric parameter, termed bump orientation, was found to be crucial to the performance under swept flows. Hinchliffe and Qin [20] achieved significant drag reduction by placing 3D bumps in the sensitivity regions on the M6 wing upper surface.…”

“…18 Recently, Jones et al. 19 investigated the effects of swept flows for 3D bumps, and a new geometric parameter, termed bump orientation, was found to be crucial to the performance under swept flows. Hinchliffe and Qin 20 achieved significant drag reduction by placing 3D bumps in the sensitivity regions on the M6 wing upper surface.…”

Vortex-Generating Shock Control Bumps for Robust Drag Reduction at Transonic Speeds

“…In 2013, Deng et al [17] put an array of optimized 3D contour bumps on a low-sweep supercritical wing and achieved the same cruise drag as that with a higher sweep angle. Later, Jones et al [18] investigated numerically the applications of 3D wedge-shaped bumps on an infinitely swept wing and concluded that well-designed 3D bumps on swept wings could offer drag reductions comparable to those on unswept wings. At the same time, the wind tunnel tests conducted by Zhou et al [19] confirmed that the 3D contour bumps on a supercritical swept wing offered better drag reductions in comparison with other passive shock control methods.…”