Volume 11 Issue 3 ( September 2024)

The maritime industry is actively transitioning to electric watercraft to curb greenhouse gas emissions and reduce dependence on fossil fuels. The Boat Motor Conversion Program, shifting from Internal Combustion Engines (ICE) to electric motors, provides an eco-friendly alternative for water transportation, addressing water pollution and noise concerns. The study focuses on the propulsion engine, utilizing a Brushless Direct Current (BLDC) motor as a boat mover. BLDC motors inherently exhibit cogging torque due to permanent magnets in the rotor interacting with the stator slots and skew angle. This article investigates the acoustic characteristics of BLDC motors, analyzing noise generated during two conditions: the motor submerged in a water tank and installed outside. Sound level data was analyzed using the Fast Fourier Transform (FFT) method to determine sound pressure values across frequencies. Results consistently show higher sound power signals for motors tested within the water tank, with Root Mean Square (RMS) differences ranging from 0.58 to 3.54 dB. Despite variations, noise levels with the motor loaded onto the outboard motor submerged in the water tank remained within acceptable limits. The findings suggest that the BLDC motor with stator skewing offers a viable solution for electric watercraft propulsion with manageable noise levels in diverse conditions.

Keywords: power spectral density; sound pressure level; noise; outboard motor