English español
Search
 

Repositorio de la Universidad de Oviedo. > Producción Bibliográfica de UniOvi: RECOPILA > Artículos >

Please use this identifier to cite or link to this item: http://hdl.handle.net/10651/51734

Title: On the structure of turbulence in a low-speed axial fan with inlet guide vanes
Author(s): Fernández Oro, Jesús Manuel
Argüelles Díaz, Katia María
Santolaria Morros, Carlos
Blanco Marigorta, Eduardo
Issue date: Oct-2007
Publisher: Elsevier
Publisher version: http://dx.doi.org/10.1016/j.expthermflusci.2007.04.008
Citation: Experimental Thermal and Fluid Science, 32(1), p. 316-331 (2007); doi:10.1016/j.expthermflusci.2007.04.008
Format extent: p. 316-331
Abstract: This paper analyzes the structure of turbulence in a single stage, low-speed axial fan with inlet guide vanes. Turbulence intensity values and integral length scales have been obtained using hot-wire anemometry for three different operating points and two different axial gaps between the stator and the rotor. These measurements were carried out in two transversal sectors, one between the rows and the other rotor downstream, covering the whole span of the stage for a complete stator pitch. Since total unsteadiness is composed of the contribution of both periodic and random unsteadiness, a processing data method was developed to filter deterministic unsteadiness in the raw velocity traces. Velocity signals were transformed into the frequency domain by removing all the contributions coming from the rotational frequency, the blade passing frequency and its harmonics. Consequently, coherent flow structures were decoupled and thus background levels of turbulence – RMS values of random fluctuations – were determined across the stage. Additionally, this unsteady segregation revealed further information about the transport of the turbulent structures in the unsteady, deterministic flow patterns. Therefore, anisotropic turbulence, generated at the shear layers of the wakes, could be identified as the major mechanism of turbulence generation, rather than free-stream, nearly isotropic turbulence of wake-unaffected regions. Finally, spectra and autocorrelation analysis of random fluctuations were also used to estimate integral length scales – larger eddy sizes – of turbulence, providing insight on the complete picture of the turbulent flow.
URI: http://hdl.handle.net/10651/51734
ISSN: 0894-1777
Sponsored: This work was supported by the Research Projects ‘‘Modeling of Deterministic Stresses in Axial Turbomachinery’’, ref. DPI2006-09712, CICYT, and ‘‘Characterization of the Generation of Aerodynamic Noise due to the Interaction between the Rotor Blades and the Guide Vanes in Axial Flow Fans’’, ref. DPI2006-15720, CYCIT.
Project id.: CICYT/PI2006-09712
Appears in Collections:Energía
Artículos
Investigaciones y Documentos OpenAIRE

Files in This Item:

File Description SizeFormat
On the structure.pdfPreprint del articulo1,35 MBAdobe PDFView/Open


Exportar a Mendeley


This item is licensed under a Creative Commons License
Creative Commons

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

 

Base de Datos de Autoridades Biblioteca Universitaria Consultas / Sugerencias