Improvement of the Performance of a Waterjet by Means of Polymeric Additives—Experimental Investigation

Abstract

An experimental investigation was carried out to test the possibility of improving the propulsive performance of waterjets by the introduction of polymeric macromolecules in water solution. Four pumps were tested either in closed and open circulating loops or in a static waterjet plant. It was clearly demonstrated that polymeric dilute solutions of Polyox WSR-301 always produced an increase of pump head, static thrust and efficiency, together with shaft power reduction. Improvements up until 20 percent could be obtained. On the basis of the distribution and of the weight of the losses inside the pump, an interpretation of the effect is given together with a suggestion for a more simple method to obtain it.