Radial turbine with guide vanes for reducing vibrations

A turbine comprises a turbine wheel (11) having radial blades and supported in a housing (1) for rotation about an axis (12). An annular inlet passageway (4) extends radially inwards towards the turbine wheel, the inlet passageway (4) being defined between first and second facing annular walls (5,6). An annular array of vanes (10) extend across the inlet passageway (4). Each vane (10) has a trailing edge (10a) extending adjacent the turbine wheel blades, wherein the trailing edge (10a) of each vane (10) deviates from a straight line over at least a portion of its length defined between its ends.