Analysis of the motions and effects of hairpin vortices

Thesis/Dissertation · Thu Jan 01 04:00:00 EST 1987

OSTI ID:6008384

Hon, T L

Recent experimental studies strongly suggest that the hairpin vortex plays an important, and possibly dominant, role in the dynamics of turbulent flows near walls. In this study, various aspects of the motion of hairpin vortices near solid walls are addressed on a theoretical basis. In particular, the following topics are of interest: (1) the nature of the evolution of hairpin vortices in a shear flow; (2) the type of flow induced near a wall by a convected hairpin vortex; (3) the character of the viscous response near a wall to the hairpin vortex motion and (4) the nature of the interaction of two hairpin vortices. In the first phase of this study, a numerical procedure is developed to allow the accurate evaluation of the trajectory of a three-dimensional vortex for vortices having small cores. The integration method is based on a numerical approximation to the Biot-Savart integral; most existing vortex calculation methods have severe stability problems for vortices with small cores. The stability problem is overcome with this method. In the second phase, the response is computed for a viscous flow near a wall due to the motion of a hairpin vortex above the wall. The results reveal that a complex, unsteady boundary-layer flow develops near the wall which ultimately develops a very strong local outward growth.

• Research Organization: Lehigh Univ., Bethlehem, PA (USA)
• OSTI ID: 6008384
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
BIOT-SAVART LAW
BOUNDARY LAYERS
FLUID FLOW
LAYERS
THREE-DIMENSIONAL CALCULATIONS
TURBULENT FLOW
UNSTEADY FLOW
VISCOUS FLOW
VORTICES