Finite element analysis for the design of novel ceramic propellers

Abstract

Ceramics are stiff, lightweight and less prone to deflection. However, ceramics have not historically been used in propeller applications. Little is known about how ceramics will react to the various loading situations of the application. Finite Element Analysis (FEA) was performed to simulate the loading due to thrust, torque and centrifugal forces on various blade geometries. The first geometry was based on a physical test assembly made from commercially available ceramic knives. Additional geometries were created based on the scan data of a known propeller, and then removing aspects of the blade-the airfoil and the twist. Each geometry was iterated to failure for each loading mechanism. The thrust and torque distribution was determined for each blade geometry at 12,000 RPM. The combined loading for all mechanisms was simulated at this rotational speed. The blade twist lowered the deflection in centrifugal loading and the added thickness of an airfoil increased the structural integrity of the blade in flexural loading. Minimal deflection was experienced by the blade design with both a twist and an airfoil.