Canada: University of Toronto, 1992. - 163 p.Three different methods of determining the profile drag/lift ratio are considered: the SBAC method, a solidity correction method, and a new semi-empirical method. Of these, the new semi-empirical method provides profile drag/lift ratios that result in substantially more accurate optimum efficiency predictions, for both aircraft and marine propellers. This method may be applied to all propellers operating in incompressible and non-cavitating conditions. The accuracy of the optimum efficiency predictions are evaluated based on the performance data of forty Hamilton Standard aircraft propellers and thirteen Troost Series B marine propellers.
The new semi-empirical method establishes a smooth continuous relationship between aircraft and marine propellers, which provides a quantitative means to evaluate the effects that certain design parameters have on the on the optimum operating efficiency of a given propeller. Further, this method shows that theoretical gains in marine propeller efficiency can be achieved with lower solidity propellers, provided that the propellers operate without cavitation.
