Experimental Investigation on Conventional and Unconventional Interceptors

The experimental study focused on the variations of the effectiveness of the interceptor induced by deadrise angle, longitudinal centre of gravity and interceptor geometry. More specifically three prismatic hulls with 10, 20 and 30-deg deadrise angles were tested. The Fn range studied is 1.3 to 2.8. Interceptors generate both high lift and trim reductions. In order to keep the influence exerted by the two effects on resistance reductions separate, tests with fixed trim and imposed sinkage with devices of various depths were carried out. The experimental data thus obtained resulted in an in-depth understanding of the functioning principle of interceptors. In particular, how to maximise resistance reductions by combining the position of the centre of gravity with the interceptors’ depth is explained. Finally, the study suggests two distinct unconventional interceptors that have led to significant results: resistance reduction and a widened range of speed where the work of the interceptors is particularly effective.