High Speed Model Testing With Drag Reduction

Abstract

The hydrodynamic (and wind) forces on such a ship operating at full speed will be enormous, and the flow patterns will be very complex. The friction drag is expected to be the largest contributor to the total drag. The obvious course of action is to focus significant effort on reducing the friction drag as much as possible using some type of active or passive friction drag reducing (FDR) technology.&&Initial testing of a FDR technology will be very basic (testing at high speed on a flat, cavitation-free plate in fresh water), focusing on understanding the fundamental physics of the technology, and the mechanisms of turbulence. Subsequent tests on complex shapes, including various pressure gradients, will be necessary to determine how the FDR technology will behave in complex flows (evaluating the effect of persistence, etc.). &&No test facility currently exists that meets all of the requirements to investigate the mechanisms of turbulence or test the FDR technologies at the necessary fluid speeds, pressure gradients, and length scales. To construct a new facility dedicated to this purpose may be prohibitively expensive in both time and capital.