Viscous flow computations for a large water tunnel

A new research project, involving the construction of a modern, large, closed-circuit depressurized highspeed water tunnel to support the detailed hydro-acoustic, hydrodynamic, cavitation and flow visualization based experimental campaigns, has recently been started in Istanbul Technical University. The present paper covers the fundamental viscous flow computations concerning the design of the critical parts of the tunnel, which includes the contraction and test section. Incompressible Reynolds-Averaged-Navier-Stokes computations were performed for the analyses. The simulations were carried out considering the predefined dimensions of the test section. The sixth-order polynomial-based geometry of the asymmetric contraction was determined aiming a high quality flow structure in the test section. The effect of several design parameters, such as the length and ratio of the contraction as well as the wall curvature properties, were analyzed in order to determine the best contraction geometry. The influence of the introduction of slight angles to the test section's vertical walls are also discussed.