Wake Instabilities of Tip-Loaded Propellers: Comparison between CLT and “New Generation” CLT Configurations

Tip loading is a common strategy to increase the propulsive efficiency of propellers. Solutions such as contracted and tip-loaded (CLT) “New generation” CLT propellers exploit presence an endplate (“true” or result dedicated modification rake distribution) sustain increased load at tip blade, cost more complex vortical structures. Their evolution, mutual interaction secondary vortices originated by itself, however, has not been completely deeply investigated. The current paper addresses this topic improved delayed detached eddy simulations (IDDES) flow field around two type different conditions. from root (or bended blade tip), partially observed in recent experiments, evidenced high-fidelity CFD calculations. mechanism with primary (those resulting strengthening structures, also through trailing wake that promote leapfrogging phenomenon, discussed well, comparing phenomena case optimally designed geometries (a New Generation propeller) exploiting same pressure side tip-loading concept slightly way. Results show rather instability depending on configuration open discussion effectiveness splitting single vortex into pairs structures may induce similar even worse) effects terms minima earlier destabilization.