Bollard Pull and Self-Propulsion Performance of a Waterjet Propelled Tracked Amphibian

Abstract

This paper describes the unique full-scale bollard pull and self-propulsion tests of a large amphibious tracked military vehicle with two waterjet propulsors. To provide a reference for the self-propulsion and cavitation performance, a series of sea trials and bollard pull tests were performed in a military sea bay and in a large test basin, respectively. Good overall agreement between the sea trial and the computation was observed in the speed–power relationship. The cavitation-induced breakdown phenomenon was further explored via numerical simulations. The results indicated that the uncertainties in the numerical results were dominated by the scales of vapor bubbles. The analysis showed that the selection of the vapor bubble scale factors of 1.0 for growth and 0.05 for collapse were in good agreement with the experimental results. Rapid performance breakdown occurred when sufficient suction side-attached cavities were extended into the blade mid-chord and tip-board regions.

Keywords

• waterjet
• amphibian
• self-propulsion
• bollard pull
• cavitation