Structure of turbulence in the presence of uniform shear
Abstract
The structure of the vorticity field in homogeneous turbulent shear flow is analyzed using a database generated by direct numerical solution of the unsteady NavierStokes equations with up to 128x128x128 grid points. For two Reynolds numbers, the probability distribution of the inclination angle of the vorticity vectors, twopoint correlations of the velocity and vorticity fields, and the instantaneous vorticity vectors and vortex lines in threedimensional space were examined. It is shown that homogeneous turbulent shear flow contains a large number of horseshoe vortices. These vortices are most often found in planes inclined at 45 deg to the flow direction and are formed from the rollup of sheets of transverse vorticity. These findings and similar results obtained in turbulent channel flow, lead to the conclusion that hairpin vortices are the characteristic vortical structures in all turbulent shear flows.
 Publication:

5th Symposium on Turbulent Shear Flows
 Pub Date:
 1985
 Bibcode:
 1985stsf.proc...17M
 Keywords:

 Flow Distribution;
 Numerical Flow Visualization;
 Shear Flow;
 Turbulent Flow;
 Vortices;
 Channel Flow;
 NavierStokes Equation;
 Reynolds Number;
 Simulation;
 Fluid Mechanics and Heat Transfer