EXPERIMENTAL EVALUATION OF AERODYNAMIC NOISE AND FLUCTUATIONS OF TURBULENT FLOW OVER A TERMINAL DIFFUSER OF A VENTILATION SYSTEM

Kód výsledku v IS VaVaI

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Výsledek na webu

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DOI - Digital Object Identifier

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Jazyk výsledku

angličtina

Název v původním jazyce

EXPERIMENTAL EVALUATION OF AERODYNAMIC NOISE AND FLUCTUATIONS OF TURBULENT FLOW OVER A TERMINAL DIFFUSER OF A VENTILATION SYSTEM

Popis výsledku v původním jazyce

Aerodynamic noise has a negative impact in ventilation systems particularly in an indoor space with higher demand on background noise like a residential building, a hospital and an administration building, especially in demanding space like TV or music studios. The paper deals with aerodynamic noise generated by flow over the blade grill as a terminal diffuser of HVAC systems (heating, ventilation and air-conditioning systems). The experiment was pro-vided with specific blade types and profiles. The goal of the paper is a comparison of the spec-tra of the sound pressure level, the spectra of the velocity fluctuations of the turbulent flow around the blade and the spectra of the vibration of the blade construction. The air mass flow-ing through the blade grill generates discrete tones in the acoustic spectra. These peak values were described for cylinders by Strouhal and they are in the range of the Strouhal number from 0.18 to 0.2, which are independent to the material of the cylinder. The flow over the blade grill generates more peaks of the Strouhal number at acoustic spectra than the flow over the cylinder due to the more complex shape of the blades. The results of the measurements for the blade of the HVAC diffuser indicate that the fluctuations of turbulent flow and vibration of the blade surface almost exactly correspond, in some cases, with the peaks of the Strouhal number at acoustic spectra.

Název v anglickém jazyce

EXPERIMENTAL EVALUATION OF AERODYNAMIC NOISE AND FLUCTUATIONS OF TURBULENT FLOW OVER A TERMINAL DIFFUSER OF A VENTILATION SYSTEM

Popis výsledku anglicky

Aerodynamic noise has a negative impact in ventilation systems particularly in an indoor space with higher demand on background noise like a residential building, a hospital and an administration building, especially in demanding space like TV or music studios. The paper deals with aerodynamic noise generated by flow over the blade grill as a terminal diffuser of HVAC systems (heating, ventilation and air-conditioning systems). The experiment was pro-vided with specific blade types and profiles. The goal of the paper is a comparison of the spec-tra of the sound pressure level, the spectra of the velocity fluctuations of the turbulent flow around the blade and the spectra of the vibration of the blade construction. The air mass flow-ing through the blade grill generates discrete tones in the acoustic spectra. These peak values were described for cylinders by Strouhal and they are in the range of the Strouhal number from 0.18 to 0.2, which are independent to the material of the cylinder. The flow over the blade grill generates more peaks of the Strouhal number at acoustic spectra than the flow over the cylinder due to the more complex shape of the blades. The results of the measurements for the blade of the HVAC diffuser indicate that the fluctuations of turbulent flow and vibration of the blade surface almost exactly correspond, in some cases, with the peaks of the Strouhal number at acoustic spectra.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20306 - Audio engineering, reliability analysis

Projekt

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Návaznosti

S - Specificky vyzkum na vysokych skolach

Rok uplatnění

2018

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Proceedings of the 25th International Congress on Sound and Vibration

ISBN

978-83-7880-552-6

ISSN

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e-ISSN

2329-3675

Počet stran výsledku

8

Strana od-do

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Název nakladatele

IIAV - International Institute of Acoustics and Vibration

Místo vydání

Auburn

Místo konání akce

Hiroshima

Datum konání akce

8. 7. 2018

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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