Paper 7
Measurement and Prediction of Aerodynamic Stability of an Axial-Flow
Ventilation Fan near the Stall Condition
Renjing Cao
Department
of Mechanical and Electrical Engineering,
Xiamen University
,
Fujian
,
China
Abstract
This paper attempts to
look at the unsteady flow pressure on the blade tip in order to quantify
the inception of instability of an axial-flow ventilation fan. A test rig
was set up to measure the unsteady static pressure near the rotor blade
tip region by mounting several transducers on the outer casing. The data
sampling system was configured for acquisition and post analysis. The
measurement results showed that, as the throttle was closed, the flow
disturbance appeared firstly at the rotor inlet. The subsequent
aerodynamic instability of the fan was dependent upon the time evolution
of such disturbances, which will notably be attenuated due to the viscous
flow effect passing through the blade passage. The disturbance at the
rotor inlet was shown to be enhanced as the throttle was progressively
closed, and the unstable behaviour was triggered by the large disturbance
at the rotor inlet. Using a 2D aerodynamic stability model for an
axial-flow turbomachine, the off-design points and the stall margin for
the axial-flow ventilation fan were numerically predicted and compared
with experimental results.
Key words: axial-flow
ventilation fan, aerodynamic instability, measurement, prediction, fan
stalling.
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Contents
Paper 1
Indoor
Air Quality in Fifty Residences in
Athens
: Santamouris, M., Argiroudis, K., Georgiou, M., Livada,
I.
, Doukas, P., Assimakopoulos, M.N., Sfakianaki, A., Pavlou,
K., Geros V. and Papaglastra, M.
Paper
2
Variable Air Volume-Flow Systems - A Possible Way
to Reduce Energy Use in the Swedish Dairy Industry: Rohdin, P. and
Moshfegh, B.
Paper
3
Experimental
Evaluation of Combined DCV and Economizer Cycle Using a FLC Variable Air
Volume (VAV) System: Karunakaran, R., Parameshwaran, R., Iniyan, S. and
Anand A. Samuel
Paper
4
Effects
of Nozzle Geometry on the Air Flow Jet and Temperature Distribution in an
Enclosed Space: Khan, M.I.
Paper
5
Automatic
Ventilation Control of Trickle Ventilators: Ridley,
I.
, Davies, M., Booth, W., Judd, C., Oreszczyn, T. and Mumovic, D.
Paper
6
Minimum Outdoor Air Supply for Radon in High Rise
Residential Buildings - Natural Ventilation v Air-Conditioning Unit: Lam,
K.S., Chan, E.H.W., Chan, D.W.T., Fung, W.Y., Law, K.C. and Tai, C.T.
Paper
7
Measurement and Prediction of Aerodynamic
Stability of an Axial-Flow Ventilation Fan near the Stall Condition: Cao,
R. and Hu, J.
Paper
8
Natural
and Mixed Ventilation Design via CFD and Architectural Modelling:
Todorovic, M., Ecim, O., Marjanovic, A. and Randjelovic, I.
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