In the early days of aerospace turbomachines, the value of curved vanes for higher efficiency was appreciated while designing aeroengine superchargers during WWI1. Consequently, the first design trade-off was between mechanical stress (i.e., the impeller diameter) and efficiency. In particular, a straight vane produces a higher pressure head compared to a backward curved vane. Furthermore, as the impeller RPM and diameter (i.e., the impeller tip speed) increase, the straight vane produces lower bending stresses vis-à-vis the curved vane that tries to “straighten” itself.