Numerical Simulation of Leading Edge Cavitation over 2D Hydrofoil

In the present paper, we compare two different computation methods for the simulation of leading edge cavitation. In the first one, known as interface tracking method, the cavity interface is taken as a free surface boundary in the computation domain and the calculation is performed in a single phase flow. The cavity shape is then determined apart from the flow calculation using an iterative procedure. We have used the Neptune code which derive the initial cavity shape from the envelope of a travelling bubble along the hydrofoil suction side. The second method is based on the so-called interface-capturing scheme. The TASCflow industrial code that we have used assumes a constant enthalpy (CEV) during the vaporization and condensation processes. Both methods are tested in the case of an isolated 2-D hydrofoil (NACA0009) having 100 mm chord length and 150 mm span. Both models gave good prediction of the cavity length and pressure distribution. Nevertheless, the CEV model exhibits significant instabilities when the cavity extends beyond the hydrofoil mid-chord. Moreover, results obtained with the Neptune predict well the pressure distribution near the cavity detachment. Either methods do not allow a good prediction of the drag coefficient nor the drop of the lift due to cavitation.