Effect of Cylindrical Turbulators on the Swept-Wing Boundary Layer. 2. Turbulence Structure and Jumps in Integral Parameters

The main objective of this study is to investigate the mechanism of forced transition to turbulence in a swept-wing laminar boundary layer with dominant cross-flow instability using spanwise-periodic rows of cylindrical turbulators (trip devices). Measurements using hot-wire anemometry were performed on a 25-degree swept wing model at low subsonic freestream velocities in a low-turbulence wind tunnel at the Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk. The investigated range of trip-height Reynolds numbers was between 565 and 3613. The main boundary-layer characteristics required to construct transfer functions for jumps in boundary-layer integral parameters important for numerical simulation of swept-wing flows in the presence of trip devices were obtained. The turbulence spectra are shown to agree with Kolmogorov’s and Heisenberg’s laws. Faulkner’s and Hama’s empirical formulas were verified and refined for the evolution of integral parameters in a three-dimensional boundary layer. This paper is Part 2 of the study.