Unsteady Flow About Cambered Plates.
Abstract
The evolution of a two dimensional, incompressible, rapidly decelerating, time-dependent viscous flow about a sharp-edged camber is simulated through the use of the discrete vortex model. Vorticity is represented by a distribution of discrete point vortices. Each vortex is convected in the velocity field, calculated locally using the Biot-Savart law. The roll-up of the vortex sheets, the distribution of velocity and pressure on the camber, and the drag force are calculated at suitable time intervals for a prescribed time-dependent flow. Experiments are carried out in a vertical water tunnel partly to measure the drag force and partly to record on a video tape the evolution of the wake. The measured and calculated characteristics of the flow, such as the growth of the wake and the forces acting on the camber are found to be in good agreement. Furthermore, the numerical simulation provided a plausible explanation for the cause of parachute collapse, a phenomenon which gave impetus to the numerical and physical experiments described herein. The numerical model developed during the course of the investigation is applicable to any time-dependent flow about two-dimensional cambered plates (circular arcs). (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1987
- Accession Number
- ADA184725
Entities
People
- Paul D. Munz
Organizations
- Naval Postgraduate School