2024 ASEE Annual Conference & Exposition

Over the past few years, drones have become increasingly popular due to the variety of tasks that they are able to perform. However, one hindrance to the increase in commercial drone utilization is noise generated by the vortices coming off the propellers. A recently proposed solution to minimize drone noise emission is the toroidal propeller, a unique design distinguished by its ring-like propeller. It is hypothesized that the closed-loop design of the toroidal propeller minimizes the tip vortices commonly generated by traditional propellers. Since tip vortices are known as the primary source of propeller noise, it is theorized that toroidal propellers reduce noise by mitigating this mechanism.

A team of engineering students studied torque, thrust, efficiency, and acoustic emission of six traditional and six toroidal five-inch diameter propellers. The team of students was using 3D scans and models of the propellers in Computational Fluid Dynamics (CFD) to compare with theory and real-world experimental laboratory data. Students have tested 3D printed and off the shelf propellers to compare their performance. Students have used Ansys Fluent simulations as well as the Tyto Robotics Dynamometer Series 1585 Propeller Thrust Stand and RC benchmark software to compare propeller designs. The students also designed, built and tested a safety cage that enclosed the spinning propeller, electric motor and test stand assembly. A Pitot tube connected to the thrust stand was traversed in order to measure airspeeds caused by propellers at different downstream and upstream distances from the propeller.

The purpose of this project was to develop a laboratory experimental set-up for an undergraduate aerodynamics course for the university where the engineering students are currently studying. The laboratory included 3D scanning of injection-molded propellers for application in CFD and Stereolithography SLA printing of toroidal propeller models purchased from a third party. The aerodynamics students will then be guided through the testing and CFD simulations required to obtain values for torque, thrust, efficiency, and sound levels as a function of propeller RPM. This enables students to learn the prototyping process applicable to multiple industries including the aerospace industry. This paper will also include a description of student outcomes, student involvement and response from students as well as assessment of student learning.