Turbulent boundary layers under small harmonic progressive oscillations of the free stream
Abstract
The prediction method presently used to treat the two-dimensional incompressible turbulent boundary layer of a semiinfinite flat plate, under small harmonic progressive oscillations of the freestream velocity, models the Reynolds shear stress by means of a novel single-layer eddy viscosity formulation. A differential-difference technique is used to numerically solve the governing equations, and the free stream thus treated consists of a constant mean upon which an oscillating amplitude that varies with downstream distance is superimposed. Comparisons of calculation results with those obtained by other methods, as well as with other experimental measurements, show satisfactory performance for a full range of frequencies and wave convection speeds. Wave speed changes are found to drastically affect boundary-layer response.
- Publication:
-
Aeronautical Journal
- Pub Date:
- September 1990
- Bibcode:
- 1990AeJ....94..251L
- Keywords:
-
- Free Flow;
- Oscillating Flow;
- Stream Functions (Fluids);
- Turbulent Boundary Layer;
- Eddy Viscosity;
- Flat Plates;
- Reynolds Stress;
- Traveling Waves;
- Two Dimensional Boundary Layer;
- Fluid Mechanics and Heat Transfer