Measurements of the Boundary-Layer Growth in Annular Diffusers

proper consideration must however by given to the added weight, reliability and cost factors. The data just presented covers Engine "A" with a relatively low tip speed fan. The next major step in the NASA/GE experimental Quiet Engine Program is to evaluate an engine incorporating Fan "C" which is representative of a high speed fan. Such an engine offers the advantage of having shorter length and fewer components, both of which permit important improvements in engine weight and engine cost. It is expected that the acoustic investigation of the Engine "C" technology demonstrator Will be pursued into the Spring of 1973. At that time comparable data will have been obtained on both "A" and "C" technology demonstrators and tradeoff studies will be performed to evaluate their relative merits acoustically and in terms of direct operating costs on a number of airplane applications. References