Abstract:

ESDU 14007 gives an overview of devices that are used to induce sustained transition at a well-defined location in a wind-tunnel test. A detailed discussion is given of bands consisting of distributed roughness particles, including selection of particle type, distribution density and band width and location. Programs are supplied to estimate the particle size required to induce sustained transition at important locations such as the fuselage nose, tail surfaces and upper and lower wing surfaces. To facilitate correction of wind-tunnel results to full-scale Reynolds numbers, a method is given to determine the incremental increase in boundary-layer momentum thickness caused by a roughness band. Consideration is also given to practical issues such as the need to reduce the number of roughness-band configurations employed in a wind-tunnel test campaign.