The Preliminary Design of Advanced Propulsors

Potential propulsors for current applications may vary in complexity from traditional open propellers to podded propulsors, multiple blade-row ducted units, and waterjets. In the past, the lifting-line theory has been an effective tool in establishing the principal characteristics of an optimum propeller design. Similarly, turbomachinery through-flow theory has been effective in preliminary estimates for internal flow devices such as waterjets. What is currently lacking is a single, unified approach that can be used for a wide range of propulsor types. This paper presents a possible solution to this problem, based on recent experience in detailed design methods based on coupling lifting surface theory with axisymmetric RANS/Euler solvers. In the present method, lifting-line representations of the blade rows are coupled with an axisymmetric Euler/Boundary Layer solver to provide preliminary estimates of propulsor performance.