Theoretical and experimental investigation on centrifugal fan with a special interest on fan noise

Download
2006
Bayraktar, Songül
In this study, the effects of design parameters on the fan noise level are investigated both theoretically and experimentally. For the theoretical study, a computational aero- acoustic method is used to predict the flow induced noise of a fan. This method involves the coupling of a flow solver and a wave equation solver. Unsteady flow analysis is performed with URANS using FLUENT. Then the time dependent data are processed with LMS Sysnoise to compute the acoustic radiation. Experimental studies are performed to verify the theoretical results and additionally to investigate the effects of different design alternatives on noise level of the fan. The sound pressure and intensity level measurements are performed in the full anechoic room of Arçelik A.Ş. Research and Development Laboratories. The validation experiments indicate that there is a good agreement between numerical and experimental results. The experimental study with different fan designs gives information about the noise reduction possibilities.

Suggestions

Numerical and experimental investigation of tubeaxial fan noise
Bodur, Ahmet; Çalışkan, Mehmet; Department of Mechanical Engineering (2014)
In this study, the noise characteristic of a tube axial fan is investigated numerically and experimentally. The effects of blockage plate in front of the tube axial fan on the tube axial fan noise level are experimentally investigated. A computational aero-acoustic method is used to predict the flow induced fan noise. This method couples a flow solver and a wave equation solver. Unsteady flow analysis is performed with URANS (Unsteady Reynolds Average Navier Stokes Equation) method while acoustics radiation...
Frequency-domain prediction of turbofan noise radiation
Özyörük, Yusuf; Alpman, E; Ahuja, V; Long, LN (2004-03-05)
This paper describes a frequency-domain numerical method for predicting noise radiation from ducted fans, including acoustic treatment and non-uniform background flow effects. The method solves the Euler equations linearized about a mean flow in the frequency domain. A pseudo-time derivative term is added to the frequency-domain equations so that a time marching technique can be employed to drive the acoustic field to steady state explicitly. This approach makes distributed parallel computing more viable fo...
Performance evaluation and cfd analysis of a positive displacement diaphragm pump
Gökçe, Gökay; Albayrak, Kahraman; Department of Mechanical Engineering (2011)
In order to understand flow characteristics inside a positive displacement pump, every point in the flow field must be carefully observed. Such observations are difficult, expensive and usually time consuming to achieve with physical testing. During tests one can observe flow characteristics only at the locations where the instrument device is attached, not the whole flow domain. This thesis mainly focuses on the evaluation of design and performance characteristics of a positive displacement triplex diaphra...
Experimental research on in-tube condensation under steady-state and transient conditions
Tanrikut, A; Yesin, O (2005-01-01)
In this research study, in-tube condensation in the presence of air was investigated experimentally at a heat exchanger of countercurrent type for different operating conditions. The test matrix for the steady-state condition covers the range of pressures P = 1.8 to 5.5 bars, vapor Reynolds numbers Re, = 45 000 to 94 000, and inlet air mass fraction values Xi = 0 to 52%. The effect of air manifests itself by a reduction in the local heat flux and the local heat transfer coefficient. The local heat transfer ...
Modelling of dropwise condensation on a cylindrical surface including the sweeping effect
Özler, Talip Emrah; Yamalı, Cemil; Department of Mechanical Engineering (2007)
The purpose of this study was to analyze the dropwise condensation on a cylindrical surface including the sweeping effect theoretically. For this purpose, first the problem of the equilibrium shape and departure size of drops on the outer surface of a cylinder was formulated. The equations of the surface of the drop were obtained by minimizing (for a given volume) the total energy of the drop which consists of surface and gravitational energy by using the techniques of variational calculus. The departure si...
Citation Formats
S. Bayraktar, “Theoretical and experimental investigation on centrifugal fan with a special interest on fan noise,” Ph.D. - Doctoral Program, Middle East Technical University, 2006.