The performance of axial fans in close proximity to the electromagnetic compatibility (EMC) screens was analyzed by means of an experimental parametric study. The following geometrical parameters were studied: the hub-to-tip ratio, the ratio between fan thickness and fan diameter, the porosity and thickness of the perforated plate, and finally, the distance between the perforated plate and the inlet and the outlet of the fan. Screen porosity was found to be the most important parameter. Fan performance degradation is expressed by means of two correlations: one for the deterioration in the fan pressure at the no-flow point and the other for the flow rate reduction at the free delivery point. Both correlations were formulated as functions of screen porosity and the distance between the fan and the screen. We believe that the correlations can serve as a good guide for correct fan placement in a telecommunications cabinet.

References

References
1.
Ott
,
H. W.
, 1988,
Noise Reduction Techniques in Electronics Systems
,
Wiley
,
New York
.
2.
Siebert
,
W. P.
, 2006, “
Cooling Structure for EMC Shielded High Frequency Electronics
,”
IEEE Trans. Compon., Packag. Technol.
,
29
(
1
), pp.
155
163
.
3.
Joshi
,
Y.
,
Baelmans
,
D.
,
Copeland
,
D.
,
Lasance
,
C. J. M.
,
Parry
,
J.
, and
Rantala
,
J.
, 2001, “
Challenges in Thermal Modeling of Electronics at the System Level: Summary of Panel Held at the Therminic 2000
,”
IEEE Trans. Compon., Packag. Technol.
,
24
(
4
), pp.
611
613
.
4.
Antón
,
R.
,
Jonsson
,
H.
, and
Moshfegh
,
B.
, 2009, “
Detailed CFD Modelling of EMC Screens for Radio Base Stations, A Parametric Study
,”
IEEE Trans. Compon., Packag. Technol.
,
32
(
1
), pp.
145
155
.
5.
Antón
,
R.
,
Jonsson
,
H.
, and
Moshfegh
,
B.
, 2007, “
Compact CFD Modelling of EMC Screens for Radio Base Stations: A Porous Media Approach and a Correlation for the Directional Loss Coefficients
,”
IEEE Trans. Compon., Packag. Technol.
,
30
(
4
), pp.
875
885
.
6.
Nevelsteen
,
K.
,
Baelmans
,
M.
,
De Troch
,
K.
,
Mesbah
,
M.
, and
Nelemans
,
W.
, 2006, “
Screen Characterization Under Fan Induced Swirl Conditions
,”
IEEE Trans. Compon., Packag. Technol.
,
29
(
2
), pp.
385
394
.
7.
Lin
,
S.-C.
, and
Chou
,
C.-A.
, 2004, “
Blockage Effect of Axial-Flow Fans Applied on Heat Sink Assembly
,”
Appl. Therm. Eng.
,
24
, pp.
2375
2389
.
8.
Grimes
,
R.
,
Davies
,
M.
,
Punch
,
J.
,
Dalton
,
T.
, and
Cole
,
R.
, 2001, “
Modeling Electronic Cooling Axial Fan Flows
,”
ASME.J. Electron. Packag.
,
123
, pp.
112
119
.
9.
American National Standard: ANSI/AMCA 210-07 ANSI/ASHRAE 51/07, 2007, “
Laboratory Methods of Testing Fans for Certified Aerodynamic Performance Rating.
10.
Randall
,
J. M.
,
Bercksmans
,
D.
,
White
,
R. P.
, 1996, “
A Methodology to Compare the Performance of Low Pressure Fan Test Rigs Using Non-dimensional Fan Characteristics
,”
J. Agric. Eng. Res.
,
65
, pp.
235
246
.
11.
Xu
,
T.
,
Lan
,
C.-H.
, and
Jeng
,
M.-S.
, 2007, “
Performance of Large Fan-Filter Units for Cleanroom Applications
,”
Build. Environ.
,
42
, pp.
2299
2304
.
12.
AMCA Publication 201-02 (R2007), 2007, “
Fans and Systems.
You do not currently have access to this content.