Experimental External Noise Level's Evaluation of the Combine Harvester and Simulation of the Noise Process in It

摘要

The given article reviews and analyzes noise sources in a combine harvester 'RSM ACROS-550'. The results of measurements of noise levels at the entrance to the cabin are provided. The necessity of developing a set of measures to improve the acoustic background of the considered class of machinery has been justified. The main sources of noise formation and contribution of each of them to the general level of sound pressure are determined with the help of qualitative and quantitative analysis. A simulation and analytical model of air flow distribution in the working area of the threshing block has been developed using the computer simulation software of gas flow dynamics 'SolidWorks Flow Simulation'. The complex nature of the interaction and the gas flow multidirectional trajectories while passing the rasp bars of a thresher drum through the concave zone has been revealed. It has been established that the complex air flow speed rates in some areas reach a high subsonic level, and the existing thrasher construction contains a number of acoustically active elements that causes air noise generation. On the basis of the received results the methods to improve the general acoustic background of the considered class of vehicles have been formulated.