In this paper, measurements are presented on the effects of freestream turbulence on laminar-to-turbulent transition in separation bubbles, and correlations are proposed for the locations of transition and reattachment on the basis of this data. The boundary layer development is measured on a smooth, flat plate upon which streamwise pressure gradients are imposed by a flexible, contoured wall opposite to the test plate. Two variations in the streamwise pressure distribution are investigated, and two Reynolds numbers are considered for each pressure-gradient setting. For each combination of pressure distribution and Reynolds number, the freestream turbulence intensity and length scale are adjusted systematically by varying the open-area-ratio and cell size of the grid installed at the test-section inlet. Measured quantities consist of velocity obtained with a single-hot wire probe and surface pressures measured through pressure taps.

Boundary layer, Freestream-turbulence, Separation-bubble, Transition
dx.doi.org/10.1115/GT2002-30232
ASME TURBO EXPO 2002:Heat Transfer, Manufacturing Materials and Metallurgy
Department of Mechanical and Aerospace Engineering

Yaras, M. (2002). Measurements of the effects of freestream turbulence on separation-bubble transition. Presented at the ASME TURBO EXPO 2002:Heat Transfer, Manufacturing Materials and Metallurgy. doi:10.1115/GT2002-30232