مدل پيش بيني تراز سر و صداي تراكتور دو چرخ در جاده خاكي روستايي

Power tillers are used for field operations and transportation of load and human in rural dirt roads in Iran. Inspite of their noise adverse effects on power tiller drivers and passengers, they have not been investigated so far. The present paper is the result of an investigation conducted on a 13 hp power tiller to obtain noise level prediction model in transportation. The test site is prepared according to international standards and the noise signals emitted from system are measured and then analyzed in time and frequency domain for audio frequency range (20 - 20000 Hz). The results show that the noise level in driverʹs ear reaches to 92 dB(A), which is higher than the standard limit of 85 dB(A). Also the engine speed plays a great role in noise generation for power tiller which could be considered in various applications. This is, because the noise is increased up to 7.5 dB (A) with engine speed variations. Lastly the power tiller prediction model of sound pressure level is determined using the experimental data which are useful in finding the optimum speed range for transportation activities.