Variable geometry turbine

A variable geometry turbine (VGT) comprises a wall movable to vary an inlet passageway between the inlet and turbine wheel, and a plurality of guide vanes 122 extending across the inlet passageway. The thickness of each vane at 5% of the chord from its leading edge 122a may be at least 50% of its maximum thickness to produce a blunt or bulbous leading edge. The thickness at 95% of the chord from its leading edge may be at least 40% of its maximum thickness, with a ratio of the vane trailing edge radius to the turbine wheel leading edge radius being 1.2 or greater. The vanes may produce a double wake variation in static pressure around a circumference of the turbine wheel. The vanes may have a shape at least partially defined by a thickness distribution that exponentially reduces from the leading to the trailing edge 122b, and an end treatment of the leading and trailing edges. The vanes may have a shape defined by the curves in Tables 3-6 or 9-12 multiplied by a scale factor, or defined by the thickness distribution in Table 1 and angular distribution in Table 2. Also disclosed are methods of designing vanes for a VGT.