PRE-SWIRL STATOR AND PROPELLER/STATOR EFFICIENCY

A new method for improving the propeller efficiency due to locating a pre-swirl stator array has been developed by applying linearised lifting surface theory. This method has been applied on general stators and in particular stators of low aspect ratio. The obtained results of the stator induced velocity are in exact agreement with low aspect ratio wing theory. Incorporating the stator induced velocity together with that of propeller, a new velocity field has been found which led to an improvement of propeller efficiency. Using published theoretical and experimental data of propeller characteristics, comparison has been made between propeller working alone and that working with stator. A gain in propeller efficiency has been achieved at larger advance coefficient and hence a decrease in the required propeller number of revolutions.