Experimental study of a Mach 3 bump-compression flowfield

Benjamin J. Tillotson, Eric Loth, J. Craig Dutton, J. Mace, B. Haeffele

Research output: Contribution to journalArticlepeer-review


An experimental study has been conducted of the supersonic flowfield surrounding a bump-compression surface. The bump geometry is typical of that used to reduce the Mach number and boundary-layer thickness as part of an inlet system. The compression surface was mounted in a blowdown-type wind tunnel that was operated at a Mach number of 2.95 with a unit Reynolds number of 39 × 106 m-1. Qualitative visualization of the flowfield included the use of oil streakline patterns to capture the surface-flow trends and schlieren photography to view shock waves and boundary-layer evolution along the bump surface. Static pressure measurements were obtained along the bump's centerline and at four spanwise planes. Along these same planes of investigation, laser Doppler velocimetry was used to provide mean velocity and turbulent stress distributions. The experiments showed that the bump induces a curved shock system originating from the leading edge of the compression surface without causing flow separation. The well-faired contour of the bump counteracts the initial pressure rise caused by the shock, yielding favorable pressure gradients in both the streamwise and spanwise-outward directions. These gradients push low-momentum boundary- layer fluid away from the model centerline to the sides of the bump. This results in a downstream boundary layer along the bump centerline that is thinner (by a factor of 2) and less turbulent than the incoming boundary layer.

Original languageEnglish (US)
Pages (from-to)545-554
Number of pages10
JournalJournal of Propulsion and Power
Issue number3
StatePublished - 2009
Externally publishedYes

ASJC Scopus subject areas

  • Aerospace Engineering
  • Fuel Technology
  • Mechanical Engineering
  • Space and Planetary Science


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