Optimizations of inlet box geometry for high pressure axial flow fans
2011 (English)Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE credits
Student thesis
Abstract [en]
Abstract
In this thesis computational fluid dynamics (CFD) simulations are carried out on a two-stage axial flow fan manufactured by Fläkt Woods. The fans are used in modern boiler plants.
Geometrical modifications of the two-stage axial flow fan are investigated theoretically with the aim to improve the efficiency and reduce the noise of the fan. As a consequence the cost for electricity and acoustic treatment for the boiler plant will be lowered. These modifications are adjustments of the upstream curvature of the guide vanes in front of the first impeller and an increase of the size of the inlet box or introduction of two extra guide vanes in the inlet box. Two properties, directly related to sound generation of the fan are, used in the optimization: 1) high uniformity of the flows upstream of the first rotor and 2) low pressure drop in the inlet box.
The engineering finite element software COMSOL Multiphysics, is used for the geometrical modifications in the model and the CFD simulations.
The simulations have shown that the best geometrical modifications investigated in this thesis is to increase the size of the inlet box. This has showed an improvement in both uniformity of the flow and pressure drop.
Place, publisher, year, edition, pages
2011. , p. 54
Keywords [en]
CFD simulations, COMSOL Multiphysics, Fluid dynamics, Two-stage axial flow fan.
Identifiers
URN: urn:nbn:se:lnu:diva-10996OAI: oai:DiVA.org:lnu-10996DiVA, id: diva2:401523
Uppsok
Physics, Chemistry, Mathematics
Supervisors
Examiners
2011-03-032011-03-032011-03-03Bibliographically approved