A joint experimental and computational study has investigated the flow
field structure created by three crossing oblique shock waves interact
ing with a turbulent boundary layer, Such an interaction is of practic
al importance in the design of high-speed sidewall-compression inlets.
The interaction is created by a test model consisting of two vertical
sharp fins mounted at 15-deg angle of attack to a horizontal flat pla
te. A third compression surface of 10-deg angle is mounted to the plat
e between the two vertical fins. The Mach 3.85 flowfield is examined e
xperimentally through kerosene lampblack and planar laser scattering v
isualizations. The results are used to develop a flowfield model of th
e interaction structure. This structure is found to consist of a compl
ex wave pattern overlying a viscous separated region. The presence of
the 10-deg compression ramp reduces the severity of the boundary-layer
separation compared to interactions created by the two fins alone, Ad
ditionally, the experimental flowfield data are compared with a comput
ational solution using a modified kappa-epsilon (Rodi) turbulence mode
l. A comparison of the results shows that, despite the complexity of t
he flowfield, the computed solution does reveal several of the key flo
w features observed experimentally.