摘要

This paper aims at an experimental demonstration of the free stream turbulence velocity and length scales role in the by-pass boundary layer transition. The start/end of transition region was achieved at the same interval of locations by two ways. The first way was controlling of turbulence level at very small turbulence length scale changes and the second way was controlling of the turbulence length scale at constant turbulence level (COST/ERCOFTAC Test Case T3A+). The collected data can serve for searching of a proper turbulence parameter as a function of the free-stream turbulence scales applicable for universal description of the by-pass transition. Some attempts to find such a parameter have been done but without success since now.