Fan Noise Reduction Using Tubercle Effect

Abstract

The propeller is an important component of any aircraft that is powered by turboprop, piston engines, or electric motors. Propeller-driven planes have a better propulsive efficiency than planes powered by conventional engines. Because less torque and hence less power is required from the engine to move the propeller, a propeller that spins effectively through air results in environmentally friendly and cost-effective flights. The objective of this thesis was to study the effect of leading-edge tubercles on propeller efficiency. Various aspects were studied including the effect of thrust, performance data, efficiency and noise changes by adding tubercle on propeller and the effect of tubercles on propeller performance with respect to Reynolds number. Small sized propellers were considered for this research i.e., 10 x 4.5in and 10 x 4.7in propellers were used. The calculations for thrust and torque coefficients were performed by theoretically putting the values in their respective formulas and then taking the average from the readings we got. We created our propeller CAD models (NACA-4412 configuration) on SolidWorks. We made two CAD models one for 10 x 4.5in propeller and the other for 10 x 4.7in propeller, this was done to see whether the tubercles performed in the same manner if we changed the dimensions of propeller, amplitude, and the wavelength of the tubercles slightly to make the analysis thorough. The results indicate an increase in efficiency of the modified propeller in comparison with the baseline propeller while operating at a various rotational velocities and flight speeds. An average of 12 %, 40 % efficiency increase for the 10 x 4.7in and 10 x 4.5in propellers respectively over the baseline design. This can be attributed to the tubercles added to the leading edges of the modified propeller blades. A propeller-driven aircraft with a modified propeller installed in place of the baseline propeller and a higher thrust-to-torque ratio has the potential for a higher maximum rate of climb, a shorter time to climb, higher absolute and service ceilings, a higher maximum velocity, a longer range and endurance, greener and less noisy aviation