A fluid working apparatus (130) includes a housing structure (130) with an inlet (132), an outlet (133), an outer housing member (134) defining a tubular portion with an inner surface and an inner housing member (138) within the outer housing member (130) and having an outer surface spaced from the inner surface such that a working flow chamber (141) is defined between the radially inner most portions of the outer and inner surfaces and a return chamber (140) is defined between the radially outer most portions of the outer and inner surfaces. A working assembly is positioned in the housing with a rotor (114) thereof rotatably supported in the housing structure (130) and extending into the working flow chamber (141). At least one return assembly (140, 142) is positioned within the tubular portion and configured to return fluid flow from an outlet side to an inlet side of the working assembly (141). A method of defining a re-circulating working fluid apparatus is also provided.