Simulate four main models of holes to make in the forage mower knife and find out the least noisy

Abstract

The research aims to study four models of holes in the forage mower knife or the so-called lawn mower cutting blade (rectangle, square, circle, ellipse) within a virtual environment (SolidWorks software environment) by determining the size of the virtual environment and the conditions necessary for the simulation process.  Studying the holes shows which ones produce the least noise in order to make the holes in the feed mower knife. This is because the holes contribute greatly to reducing the noise of rotating mechanical parts.  The results showed that the rectangular hole achieved less air turbulence when the area was equal, reaching 45 dB.  In addition, if the edge of the hole was slanted outward, the noise decreased and reached 35.27 dB. Additionally, rounding the corners using the “Fillet” feature, which makes the corners of the rectangle curved, reduced the noise to 32.05 dB. This simulation was based on the law of calculating the Reynolds number for flow, which relates to the fluid density, velocity, and dynamic viscosity, which are constants in this case. The equivalent diameter, which is directly proportional to the Reynolds number, varies from one hole to another. By calculation, the equivalent diameter of the rectangle is smaller than that of the rest of the holes, and therefore, it produces less noise.