Centrifugal fans with an electric motor included in the hub are commonly used in HVAC (heating, ventilation, and air conditioning) systems. A design of experiments (DOE) has been performed to study the effect of the entrance conditions of a backward-inclined centrifugal fan on its efficiency. The parameters involved are the base radius of the motor hub, the radius of the fan entry section, the deceleration factor throughout the entry zone (from the entry of the fan to the entry of the blade), and the solidity factor. Numerical simulation coupled with the DOE has been used for the sensitivity analysis of the entrance parameters. Initially, a complete factorial plan $(24)$ was performed to screen the most influent parameters and interactions. This has shown that the motor’s cap radius, as well as its interactions with other parameters, is not significant. A second DOE, using composite central design (CCD which has a second order of accuracy) has then been performed on the remaining parameters (radius of the fan entry section, deceleration factor, and the solidity factor). The effects of these parameters and their interactions on the fan efficiency are now presented. A linear regression with three parameters has been performed to establish the efficiency distribution map. The methodology employed is validated by comparing the predicted results from the DOE and those from the numerical simulation of the corresponding fan.

1.
Stepanoff
,
A. J.
, 1957,
Centrifugal and Axial Flow Pumps: Theory, Design & Application
,
Wiley
,
New York
.
2.
Eck
,
B.
, 1973,
Fans Design and Operation of Centrifugal, Axial-Flow, and Cross-Flow Fans
,
Oxford, Pergamon Press
,
New York
.
3.
Rai
,
M. M.
, and
,
N. K.
, 1990, “
Multi-Airfoil Navier-Stokes Simulations of Turbine Rotor-Stator Interaction
,”
ASME J. Turbomach.
0889-504X,
112
(
3
), pp.
377
384
.
4.
Zhang
,
M. J.
,
Pomfret
,
M. J.
, and
Wong
,
C. M.
, 1996, “
Three-Dimensional Viscous Flow Simulation in a Backswept Centrifugal Impeller at the Design Point
,”
Comput. Fluids
0045-7930,
25
(
5
), pp.
497
507
.
5.
Stickland
,
M. T.
,
Scanlon
,
T. J.
,
Fernandez-Francos
,
J.
,
Blanco-Marigorta
,
E.
, and
Parrondo
,
J.
, 2002, “
A Numerical and Experimental Analysis of Flow in a Centrifugal Pump
,”
Proceedings of the 2002 ASME Joint U.S.-European Fluids Engineering Conference
,
, pp.
703
708
.
6.
Lin
,
S. C.
, and
Huang
,
C. L.
, 2002, “
An Integrated Experimental and Numerical Study of Forward-Curved Centrifugal Fan
,”
Exp. Therm. Fluid Sci.
0894-1777,
26
, pp.
421
434
.
7.
Gonzalez
,
J.
,
Fernandez
,
J.
,
Blanco
,
E.
, and
Santolaria
,
C.
, 2002, “
Numerical Simulation of the Dynamic Effect Due to Impeller-Volute Interaction in a Centrifugal Pump
,”
ASME J. Fluids Eng.
0098-2202,
124
, pp.
348
354
.
8.
Choi
,
J. H.
,
Kim
,
K. Y.
, and
Chung
,
D. S.
, 1997, “
Numerical Optimization for Design of an Automotive Cooling Fan
,”
SAE, Heat Exchanges for Automotive Design
,
1262
, pp.
73
77
.
9.
Yu
,
Z.
,
Li
,
Song
,
He
,
W.
,
Wang
,
W.
,
Huang
,
D.
, and
Zhu
,
Z.
, 2005, “
Numerical Simulation of Flow Field for a Whole Centrifugal Fan and Analysis of the Effects of Blade Inlet Angle and Impeller Gap
,”
HVAC&R Res.
1078-9669,
11
(
2
), pp.
263
283
.
10.
Luo
,
J. Y.
,
Issa
,
R. I.
, and
Gosman
,
D.
, 1994, “
Prediction of Impeller Induced Flows in Mixing Vessels Using Multiple Frames of References
,”
Inst. Chem. Eng. Symp. Ser.
0307-0492,
136
, pp.
549
556
.
11.
Lane
,
G. L.
,
Rigby
,
G. D.
, and
Evans
,
G. M.
, 2001, “
Pressure Distribution on the Surface of Rushton Turbine Blades: Experimental Measurements and Prediction by CFD
,”
J. Chem. Eng. Jpn.
0021-9592,
34
(
5
), pp.
613
620
.
12.
Bujalski
,
W.
,
Jaeorski
,
Z.
, and
Nienow
,
A. W.
, 2002, “
CFD Study of Homogenization With Dual Rushton Turbines: Comparison With Experimental Results: Part II: The Multiple Reference Frame
,”
Chem. Eng. Res. Des.
0263-8762,
80
(
1
), pp.
97
104
.
13.
ANSI/AMCA Standard 210-99
, “
Laboratory Method of Testing Fans for Aerodynamic Performance Rating
,” Air Movement and Control Association International Inc., www.amca.org
14.
Montgomery
,
D. C.
, 2001,
Design and Analysis of Experiments
,
Wiley
,
New York
.