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Sound propagation through elevated, heated jets in cooler cross-flow: An experimental study.
O Leav1, B Cazzolato1, C Howard1
1School of Mechanical Engineering, University of Adelaide, Adelaide, Australia.
The Journal of the Acoustical Society of America
|August 3, 2021
Summary
Hot exhaust plumes from power stations significantly alter sound propagation. Cooler cross-winds can increase downwind noise by up to 11 dB, impacting acoustic assessments.
Area of Science:
- Acoustics
- Fluid Dynamics
- Thermodynamics
Background:
- Sound propagation in industrial settings like gas turbine power stations is complex.
- Hot exhaust plumes interacting with cooler ambient air and cross-winds create unique acoustic challenges.
Purpose of the Study:
- To investigate the acoustic effects of hot exhaust plumes interacting with cooler cross-winds.
- To analyze how these atmospheric conditions alter sound directivity and propagation from exhaust stacks.
Main Methods:
- Reduced-scale exhaust stack experiments in a wind tunnel.
- Experimental measurements of flow and temperature fields.
- Acoustic measurements of sound directivity and intensity.
Main Results:
- Hot exhaust plumes cause non-axisymmetric sound directivity.
- Sound concentrates downwind of the exhaust stack outlet.
- Up to 11 dB increase in downwind sound levels observed under specific cross-flow conditions.
Conclusions:
- The presence of a hot exhaust plume with cooler cross-flow significantly impacts sound propagation patterns.
- Accurate estimation of downwind noise levels requires consideration of these plume and wind interactions.
- Findings are crucial for environmental noise assessments around industrial facilities.
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