Investigation of Lightweight Structural Design Techniques for Lightweight Fans

摘要

The results of an investigation of the design and fabrication problems of a minimum-weight rotating-diffuser lift system for an air cushion vehicle (ACV) are presented. A numerical method for the stress analysis of an indeterminate rotating diffuser centrifugal fan structure was reduced to practice and programmed for the IBM 1620 computer. This method was used as a tool for the analytical design of a minimum-weight RD fan. This fan, with a 64.5-inch overall diameter, was built of aluminum and was structurally tested. Stress levels throughout the fan were measured by means of 21 strain gages. Results of the tests are very encouraging and vindicate the analytical approach to fan design. Based on measured weights and stress levels, it is concluded that RD fans for ACV applications, for ratings between 100 and 1000 horsepower, can be built for 0.5 pound per horsepower. (Author)