Unsteady Flow about Cambered Plates

Impulsively-started uniform flow, decelerating at specified rates, about two-dimensional cambered plates with included angles of 120, 180, and 240 degrees has been investigated both theoretically and experimentally. The experiments were conducted in a vertical water tunnel. The forces acting on the cambered plates have been determined as a function of relative displacement of the fluid. The evolution of the vortices was visualized by means of various dyes and polystyrene beads. A numerical analysis was carried out through the use of the discrete vortex model. Vorticity is represented by a distribution of discrete line vortices. Each vortex is convected in the velocity field according to the Biot-Savart law. The rollup of the vortex sheets, the distribution of velocity and pressure on the cambers, and the drag and lift forces are calculated at suitable time intervals for a prescribed time-dependent flow. The results are compared with those obtained experimentally.