Scale Effects on Cavitation on a Hydrofoil

Paper i proceeding, 2004

In this work, a study on the scale effects on cavitation for the TU Delft Twist 11 hydrofoil is presented. The numerical simulations were performed with RANS, and cavitation is modeled by the mixture approach with the Schnerr-Sauer mass transfer model. Results are validated with model scale experimental data provided by TU Delft and EPFL. The numerical predictions show that scale effects have an influence on the cavity length, shedding behavior, vortical structures, and the re-entrant jet. In comparison with model scale observations, the attached cavity length extends further in the downstream direction. In addition, the vortical structures appear weaker at full scale which initiates intermittent cavities that collapse at an earlier stage during a shedding cycle relative to model scale. Analysis of the re-entrant jet shows different behaviors at model and full scales, which has been attributed to the jet momentum and how it travels to the leading edge. In addition, the possibility of using wall function at full scale is studied and shows promising results when compared with the results of the wall resolved approach.