Thermocouple Rakes for Measuring Boundary-Layer Flows

Thin-film devices that comprise heaters in combination with thermocouples have been developed for measuring flow velocities extremely close to solid surfaces, at several distances from the surface of interest. Devices that perform this function are denoted generally as “boundary-layer rakes.” The measurement data acquired by boundary-layer rakes are needed for calculating viscous shear forces, for developing mathematical models of turbulence to be used in computational fluid dynamics, and as feedback in some flow-control systems.