MEASUREMENT STUDY OF AIRCRAFT JET ENGINE NOISE EFFECTS AND CONTROL

Abstract

Aircraft noise is a significant concern to those who work or live near airports; it is an issue that persists and adversely impact pilots, engineers, technicians, students and surrounding communities. This paper deals with the noise measurements in decibel A- weighting (dBA) and suggests means to control its effect for a military trainer jet engine aircraft. The measurements were carried out using the Impulsive Precision Sound Level Meter, B&K 2209. SOKO G-2 Galeb is a fixed wing military trainer jet aircraft. The aircraft was located at the air academy (Misurata city) in the aircraft station and at the maintenance workshop, where workers are exposed to hazardous noise levels during day and night. The noise level was measured at different engine speeds (40% and 60% of maximum engine speed) with one aircraft in operation on the ground station. The results,noise levels with a permissible exposure time in (hours) at different locations to the aircraft centre line were measured and discussed and presented in a form of contours for the comfort and safety of the workers. It was found that the highest noise level occurs at the jet exhaust, (zero angle) along the fuselage centre line of the Galeb aircraft and the lowest noise level occurs at an angel of 120 degree for a fixed radius (r), for both engine speeds on the ground. Similar noise level variations were obtained when the exposure angle theta, θ was fixed at different radius from the fuselage centre line of the aircraft. Suggestions to reduce the noise effect on the workers around the aircraft and buildings were discussed to improve their comfort and safety.