Design and calibration of a water tunnel for skin friction research

A new water tunnel facility has been designed for application in skin friction and boundary layer research. The closed loop, recirculating facility with working section 200 x 600 x 2400 mm and test surface 600 x 1000 mm has been designed to operate at working section flow speeds of up to 2 m/s (Reynolds number based on test surface length 2.2 x 10^6). A force balance enables the direct measurement of drag on test surfaces. Hot film, pitot and multi-hole pressure probes are used to investigate the near wall flow.