Abstract :
Noise at the nozzle occurs due to fluctuations in air velocity and pressure
caused by turbulent nozzle flow. Noise analysis on the nozzle is important so that it
can minimize the noise. This study was conducted to obtain a comparison of sound
pressure level (SPL) between the chevron nozzle and nozzle without a chevron and
determine the efficiency of the chevron nozzle in suppressing noise levels.
In this study, 3 receivers and an air velocity of 188.65 m/s were used. The
turbulent flow approach was analyzed using the Large Eddy Simulation method
and the acoustic approach using the Ffowch William and Hawkings (FWH) method.
The nozzle variations used in this study are SMC000, SMC002, SMC003, SMC006,
and SMC007. The results obtained from this simulation are Sound Pressure Level,
contour velocity, contour static pressure, and contour dynamic pressure.
The results showed that the highest noise occurred at the chevron nozzle
variation SMC007 of 87.5 dB and the lowest noise occurred at the chevron nozzle
variation SMC003 of 87.5 dB. The data shows that the chevron nozzle variation
SMC003 is more efficient in suppressing the noise level produced by the jet engine.
The geometry of this variation has 10 chevrons with a chevron angle of 5? and a
chevron length of 7.11 mm. This research is useful to understand the comparison
of chevron nozzle and without chevron, the effect of various chevron nozzle
variation.