Miniature, Shear Stress Measurement System for Marine Applications

A miniature shear stress measurement system will be developed for marine hydrodynamic applications. Tao Systems will design and fabricate a miniature waterproofed sensor array with at least 32 sensor elements. The sensor will be mounted on a representativewater-tunnel model which has well-known shear stress distribution and location of flow separation. The instrumented model will be tested in Tao Systems' in-house water tunnel with a maximum rated speed of 15 knots. Well-established analytical expressionsfor shear stress distribution as a function of the location of the sensor will be used to calibrate sensors. This calibration will be verified at other flow conditions. We will also artificially change the ambient temperature of the flow field to verifythe calibration. Real-time detection of flow separation will be simultaneously demonstrated in this experiment. The design of marine vehicles relies on a knowledge of the normal and tengential forces and moments exerted by the fluid on the vehicle duringoperation. The ability to measure shear stress simultaneously at many points, and thus drag, and to detect separation regions on a maneuvering vehicle provides needed data comparison with computational fluid dynamics (CFD) analyses and for the developmentand assessment of current and future designs. There is a large market for both military and commercial applications of the solicited system.