Model Experiments for the Design of a Sixty Inch Water Tunnel Par IV

A study of the main diffuser (the diffuser following the test section) for a water tunnel was made at the St. Anthony Falls Hydraulic Laboratory as part of the research program for the design of the proposed 60-in. water tunnel of the David Taylor Model Basin, Bureau of Ships, Department of the Navy. The diffuser was designed on the basis of previous investigations of other experimenters, and the testing program was conducted to determine the action of the diffuser as it will be affected by the conditions of inflow and outflow in the recirculating system of the prototype water tunnel. It was determined that the diffuser will operate satisfactorily as to energy loss but that there will be slight maldistribution of velocity at the downstream end. It was decided, however, that this maldistribution will not be sufficiently detrimental to operation of the water tunnel to warrant making the diffuser longer and of a smaller angle of divergence.