Paper 5
Prediction of Flowfield and Acoustic Signature of a Split-type
Air Conditioner
Youjun
Zhu, Hua Ouyang, Zhaohui Du
School
of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200030,
P R China
Abstract
The
fan is one of the major noise sources of an air conditioner. Because of
the presence of other components in the fan assembly, such as the
bell-mouth, outlet grille and compressor chamber, the ingested and
discharged flow fields around the fan impellers are distinctly different
from those in a free field. Therefore, the noise generation mechanisms
become much more difficult to analyze and model. This paper concentrates
on understanding the generation mechanism and evaluating the noise in the
fan system of a split-type air conditioner. Acoustic measurements were
performed to analyze noise characteristics and to evaluate the effect of
each component. Large eddy simulation was applied to predict detailed flow
fields. Accordingly, unsteady flow data were fed into an acoustic analogy
model to evaluate radiated sound. The predicted discrete frequency noise
and sound spectrum proved that computation is accurate compared to
measurement.
Key words: Split-type
air conditioner, noise, acoustic problems, LES.
References
Dunn MH and Tweed
J; (1999) “The application of a boundary integral equation method to the
prediction of ducted fan engine noise”, J Sound Vib. 227,
pp1019-48.
Estevadeordal J, Gogineni S, Copenhaver W, Bloch G and Brendel M:
(2000) “Flow field in a low-speed axial fan: a DPIV investigation”, Exp
Therm Fluid Sci. 23, pp11-21.
Ffowcs WJE and
Hawkings DL: (1969) “Sound generation by turbulence and surfaces in
arbitrary motion”, Phi Trans Roy Soc., A264.
Fukano T and Jang,
CM (2004) “Tip clearance noise of axial flow fans operating at design
and off-design condition”, J Sound Vib. 275, pp1027-1050.
Greeley DS and
Kerwin JE: (1982) “Numerical methods for propeller design and analysis
in steady flow”, The society of Naval Architects and Marine Engineers
Transactions. 90, pp415-453.
Lighthill M.J:
(1952) “On sound generated aerodynamically I: General theory”, Proc
Royal Soc. 211, pp564-87.
Maaloum A, Kouidri
S and Rey R: (2004) “Aeroacoustic performance evaluation of axial flow
fans based on the unsteady pressure field on the blade surface”, Appl
Acoust. 65, pp367-84.
Oro JMF, Diaz KMA,
Morros CS and Marigorta EB: (2007) “Unsteady flow and wake
transport in a low-speed axial fan with guide vanes”, Journal of Fluid
Engineering. 128, pp1015-1029.
Roger M, Moreau S
and Wang M: (2002) “An analytical model for predicting airfoil
self-noise using wall-pressure statistics”, Annual Research Briefs,
Center for Turbulence Research, Ecole Centrale de Lyon. pp405-414.
Sharland IJ: (1964)
“Sources of noise in axial flow fans”, Journal of Sound and
Vibration. 1, pp302-322.
You D, Wang M, Mittal R and Moin P: (2003)
“Study of rotor tip-clearance flow using large-eddy simulation”, AIAA
Journal. No.2003-0838.
|
Contents
Paper
1
Editorial: Summer Comfort and Cooling - an INIVE Workshop
Paper
2
Space Planning, Ventilation and Energy Efficiency in Offices
Paper
3
Unveiling Energy Saving Techniques for Cooling in Residential Buildings in
Ghana
Paper
4
Influence of Induction Box Ports on Near Flow Field Mixing
Paper
5
Prediction of Flowfield and Acoustic Signature of a Split-type Air
Conditioner
Paper
6
The Use of Impulse Ventilation to
Control Pollution in
Underground Car Parks
Paper
7
Estimation of the Wind Speed in Urban Areas – Height less than 10 Metres
Paper
8
Utility of Wind Catchers for Nocturnal Ventilation
|
