Holdhusen, James S.2011-06-272011-06-271948-09https://hdl.handle.net/11299/108115Bureau of Ships Contract NObs-34208The purpose of the recirculating pump in the water tunnel is to supply energy efficiently to the circulating stream so that the resistance of the circuit may be overcome. In most pump installations this is practically the only requirement for which the pump is designed, but in the water tunnel installation the secondary characteristics of the pump must be carefully controlled. Some of these secondary characteristics which would seriously affect the usability of the water tunnel are pulsation, cavitation, noise level, stream rotation, and outflow velocity maldistribution. This study will not discuss the pump design since that will be the responsibility of the eventual manufacturer. Rather, it will furnish fundamental information based on the tests of the model water tunnel which the manufacturer should know in order to design the pump properly.en-USReport