Abstract

This report is an extension of the paper entitled "Effect of Smoothness of Bucket Surface on the Efficiency of a Pelton Wheel" read at the special joint meeting of the Society of Mechanical Engineers and the Society of Naval Architects of Japan, held at Fukuoka in March 1920. The wheel tested in the previous experiment was of a Pelton-Doble type, designed to develop 6 B. H. P. under 30 metre head at 400 r. p. m. previous results have shown that the efficiency of the wheel with polished bronze buckets, called "A" was 2.6% higher than that with rough bronze bukets "C" and 0.8% higher than that with painted rough bronze buckets "B", at a normal nozzle opening and a normal speed. In this experiment the same Pelton wheel was tested with rough cast iron and with enameled cast iron buckets ; and the result has shown that the enameled bucket was equal in its character to the polished bucket "A", the rough cast iron being almost to the rough bronze "C". The advantage of the enameled cast iron bucket with respect to the efficiency as well as the economy of material and construction was thus proved.