Slowly rotating pulsed radiation source

An approximate analytical solution is obtained for the problem of a rotating monopole such as a propeller, pump vane fan or other bladed mechanism. The radiation is assumed to be pulsed, i.e., occurring in the part of the circular trajectory that a pulse follows. The amplitude of the induced pressure when the sector within which the source radiates is small is found to be independent of the parameter L, which corresponds to the assumption of an incompressible liquid. An example illustrates the advantage of the approximate solution.