Numerical prediction of transition boundary-layer flows using new intermittency transport equation

Abstract

AbstractIn this paper, a new transport equation for the intermittency factor is proposed to model the transition flows. The intermittency behaviour of the transition flows is incorporated into the differential methods for solving the boundary-layer equations, which deal numerically with the basic partial differential equations. The present model accuracy and validity have been tested against a series of recent published experiments, for low Reynolds number, including flows with different freestream turbulence intensities and different pressure-gradients, such as aerofoil and flat plate flows. A comparison of the present method and two different prediction techniques is also given.The significance of the proposed transport intermittency equation is to reproduce the streamwise variation of the intermittency factor in the transition zone. This method is found suitable and reliable to predict flows with positive or favourable pressure-gradient cases and with turbulence intensity level up to 6%.The method also confirmed the importance of estimating the start of transition, present formula. The present formula is suitable and straightforward to use. For all test cases good agreement between the computed results and the experimental data are observed.