Abstract

In order to investigate the laminar-turbulent transition, calculated by means of boundary layer method, in a sufficiently exact manner, theoretical reasults on turbulent spot formation have been compared with experimental data obtained by means of the soot removal method on a flat plate and with various other results obtained by measuring the local heat transfer and by hot-wire anemometry. Futhermore, an experimentally founded model conncept has been developed explaining for formation and development of the turbulent spot within the transitional boundary layer. As a result of these invastigations, characteristic correlations batween momentum thickness, Reynolds number and free-stream turbulence level with the intermittency factor as a parameter of the flat plate without pressure gradient have been obtained. A characteristic showing the pressure gradient influence on the laminar-turbulent has been established as well. The reliability of those fields of characteristics can be verified experimentally by means of the sample method.