Jeffery A. Giordano
Deere & Co. Technical Ctr., 3300 River Dr., Moline, IL 61265
The use of relatively quiet engines and electric motors on lawn mowers has shifted much of the emphasis on noise reduction to the under deck flow-induced noise sources. However, the environment under an operating mower deck makes it difficult to either model or directly measure the pressure field. This presentation will detail a rather simple scheme which was used to first measure, then animate the pressure field in a plane directly below an operating deck, using an inertial frame of reference. Time synchronous averaging was employed to collect the data at discrete sample points. Individual data planes were then reconstructed representing all the sample points at specific blade locations. The measurement planes were contoured and used as separate frames in a slow-motion animation of the pressure field.