Design, build and testing of an aerial rim driven fan

• Main Author: Tay, Jia Hui
• Other Authors: Chan Wai Lee
• Format: Thesis-Master by Research
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Aeronautical engineering
• Online Access: https://hdl.handle.net/10356/155763
• Institution: Nanyang Technological University

In this thesis, a rim driven fan (RDF) was designed, manufactured and tested. RDFs, also known as hubless or shaftless propeller and fans, are commonly used in marine industry as they have the advantage of undisrupted inflow and do not suffer failures caused by fishing lines and netting. RDFs are well studied and established in marine applications with commercial models available in water. There are no studies for operation in air, so the aim of this thesis is to study RDFs’ applicability in air. The prototype was approached by designing the blades using a novel Schmitz model. Schmitz model was initially developed for wind turbine blades and was extended to propellers in this thesis. Computational Fluid Dynamics (CFD) simulations have been conducted for the blade designed using the adapted Schmitz model to account for radial flow and non-linear effects that are not considered in the original theory. The addition of an outer nacelle and nozzles to increase thrust was also investigated. To power and test the blade, an electric motor was designed and adjusted using commercial software that uses finite element method to predict electric magnetic fields. CFD techniques were first validated with published experimental data. RDF design parameters such as number of blades, airfoil profile and design tip speed ratio were investigated to determine the optimum design. Different nozzle designs were also simulated to examine the additional thrust. Motor-propeller matching was conducted to check that the motor design would be sufficient to provide the necessary torque for the propeller at a given rotational speed. The prototype for the blade, outer casing, and rim were manufactured using selective laser sintering. The arc magnets for the motor were selected such that the number of magnet poles are 12. The wiring for the 18 stators was performed normally using six rounds per stator. A commercial electronic speed controller was used to regulate the pulsing input for the motor. Comparison of measured thrust coefficient with CFD is good showing a correlation coefficient of 0.95. Measurements of torque coefficient are more difficult because of small values that lead to larger variations in results. However, the measurements also indicate an average correlation of 0.78.