Accession Number : ADA184725

Title :   Unsteady Flow About Cambered Plates.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CA

Personal Author(s) : Munz,Paul D

PDF Url : ADA184725

Report Date : Jun 1987

Pagination or Media Count : 51

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)

Descriptors :   *CAMBER, *UNSTEADY FLOW, *MATHEMATICAL MODELS, *RIBBON PARACHUTES, VORTICES, COLLAPSE, TWO DIMENSIONAL, VISCOUS FLOW, INCOMPRESSIBLE FLOW, THESES, COMPUTATIONS, PLATES, CIRCULAR, VORTICES, TIME DEPENDENCE, WATER TUNNELS, WAKE

Subject Categories : Fluid Mechanics
      Operations Research
      Gliders and Parachutes

Distribution Statement : APPROVED FOR PUBLIC RELEASE