A wave disc engine apparatus is provided. A further aspect employs a constricted nozzle in a wave rotor channel. A further aspect provides a sharp bend between an inlet and an outlet in a fluid pathway of a wave rotor, with the bend being spaced away from a peripheral edge of the wave rotor. A radial wave rotor for generating electricity in an automotive vehicle is disclosed in yet another aspect.

A turbine row for an axial or mixed-flow fluid machine may include an airfoil, having a leading edge, a trailing edge, a pressure surface and a suction surface. The turbine row may further include two endwalls, extending from upstream of the airfoil leading edge to downstream of the airfoil trailing edge. The endwalls may define an inlet upstream of the leading edge of the airfoil and an outlet downstream of the airfoil. The endwalls have a contoured geometry which provides an increase in channel height from the inlet to the outlet and guarantees a throat area larger than the area of the inlet.