Hydrofoil vibration and noise reduction with leading edge isolation

A technique for reducing the vibration and noise from hydrofoils experiencing unsteady hydrodynamic loads was demonstrated experimentally. Such unsteady loads are generated when hydrofoils interact with approach-flow disturbances and are concentrated in the vicinity of the leading edge. A single stage vibration isolation mount was incorporated into a hydrofoil at its 20% chord location to inhibit the unsteady loads generated near its leading edge from being transmitted to the remainder of the foil and any structures coupled to it. The hydrofoil was tested in a water tunnel facility with a wake generator placed upstream to produce the approach-flow disturbances. The reduction in the unsteady loading on the portion of the hydrofoil isolated from the leading edge was inferred from vibration measurements; 5 to 10 dB reductions were demonstrated.