摘要
We report a simple but accurate description of flat plate transitional flow based on a structural ensemble dynamics(SED) theory of wall turbulence. It is postulated and verified by simulation data that a multi-layer stress length(SL) function ?12 presents a two-state structure in the streamwise x direction, characterizing the laminar-turbulent transition. The resulting algebraic model(called SED-SL) predicts correctly for the first time the entire streamwise profiles of the friction coefficient, Cf(x), of all seven sets of experimental(of e.g. T3 series) and simulations data of flat plate transitional flows, with varying incoming turbulence intensities Tu(or scales), superior to other closure models, with a two-state correlation for transition location Rex*= 3.3 × 10^6(1 +(Tu/0.65)^4)^-1.5/4. The extension to accurate description of transitional flows of engineering interests is discussed.
We report a simple but accurate description of flat plate transitional flow based on a structural ensemble dynamics（SED） theory of wall turbulence. It is postulated and verified by simulation data that a multi-layer stress length（SL） function ?12 presents a two-state structure in the streamwise x direction, characterizing the laminar-turbulent transition. The resulting algebraic model（called SED-SL） predicts correctly for the first time the entire streamwise profiles of the friction coefficient, Cf（x）, of all seven sets of experimental（of e.g. T3 series） and simulations data of flat plate transitional flows, with varying incoming turbulence intensities Tu（or scales）, superior to other closure models, with a two-state correlation for transition location Rex*= 3.3 × 106（1 +（Tu/0.65）4）-1.5/4. The extension to accurate description of transitional flows of engineering interests is discussed.
基金
supported by the National Natural Science Foundation of China(Grant Nos.11452002,and 11521091)
