Near-Wake Measurements of a Delta Wing in a Supersonic Stream

Abstract

The near-wakeregion of a 75-deg sweptback delta wing wasstudied experimentally in a Mach 2.49 stream. Fivehole conical probe measurements were conducted vertically and horizontally through the primary vortices at the trailing edgeand half-chord downstream oftheplanformfor7-and 12-deg anglesofattack.TheMachnumberand pressure distribution proe les are summarized, and comparisons of e ow properties at different survey stations are presented. A novel calibration approach using a three-dimensional Navier ‐Stokes solver to generate numerically the calibration data for a blunt-nosed e ve-hole conical probe over a range of Mach numbers and pitch angles was employed.Themagnitudeofthepitot,total,andstaticpressuredee citsinthewakeregionincreasedwithincreasing angle of attack for the same measurement plane and decreased with the downstream distance. The swirl proe les have supersonic and high transonic peak magnitudes, and estimated core dimensions suggest vortex stretching in the vertical direction and convection downstream. A decrease in the radial Mach number component cone rms the vortex trajectory changes from a strong downward e ow over the planform to a gradual return toward the freestream in the near wake. Unlike the experimental results from transonic and low-speed leading-edge vortices, the axial and total Mach number distributions in supersonic vortices are found to be wakelike.