Competing Broadband Noise Mechanisms in Low Speed Axial Fans

2004 ◽  
Author(s):  
Stephane Moreau ◽  
Michel Roger
Keyword(s):  
Broadband Noise ◽  
Low Speed ◽  
Axial Fans

Investigation on the Influence of Mesh Topology and Freestream Turbulence Intensity in Broadband Noise Prediction of Axial Fans

2014 ◽  
Author(s):  
A. Zanon ◽  
M. De Gennaro ◽  
H. Kuehnelt ◽  
D. Langmayr ◽  
D. Caridi
Keyword(s):  
Experimental Data ◽  
Broadband Noise ◽  
Computational Time ◽  
Noise Prediction ◽  
Hybrid Mesh ◽  
Low Speed ◽  
Mesh Topology ◽  
Inflow Turbulence ◽  
Axial Fans ◽  
The Impact

Aerodynamic noise prediction is a major challenge in computational aeroacoustics due to the complexity of phenomena involved such as turbulence and laminar to turbulent transition. Accurate numerical methodologies, capable to provide reliable predictions in a reasonable computational time, are of large interest for the industrial design of Heating, Ventilation and Air-Conditioning (HVAC) systems. The objective of the present research work is to benchmark different CFD/CAA simulation setup (i.e. mesh topologies, boundary conditions) for predicting the broadband noise generated by low speed axial fans to develop guidelines for reliable and computationally affordable simulation. In previous works the authors investigated the capabilities of the Zonal LES technique coupled with the Ffowcs Williams-Hawkings acoustic analogy for the prediction of the noise generated by an unducted low speed axial fan. The results showed a good agreement with aerodynamic and aeroacoustic experimental data. Despite the achievements obtained so far, the high physical and numerical complexity of the problem calls for further investigations. The latest developments, presented here, focus on the impact of the mesh topology and the inflow turbulence on the far field noise prediction. Two computational meshes with different topology are investigated: an unstructured-hybrid mesh, which can be generated with fast and highly automated methods, and a structured-hybrid mesh, which allows better control of the volume mesh around the blade. Both meshes are designed to adequately resolve the boundary layer, providing LES driven values of y+, x+ and z+ on the blade surface for the operating condition considered. Two different levels of inflow turbulence are studied, one representing an ideal turbulence-free unbounded environment, and one mimicking the experimental measurements environment. All the aerodynamic and aeroacoustic simulation results presented are benchmarked with experimental data acquired by the authors.

Competing Broadband Noise Mechanisms in Low-Speed Axial Fans

AIAA Journal ◽  
2007 ◽  
Vol 45 (1) ◽  
pp. 48-57 ◽  
Author(s):  
Stéphane Moreau ◽  
Michel Roger
Keyword(s):  
Broadband Noise ◽  
Low Speed ◽  
Axial Fans

scholarly journals Suppression of broadband noise radiated by a low-speed fan in a duct

2010 ◽  
Vol 128 (1) ◽  
pp. 152-163 ◽  
Author(s):  
L. Huang ◽  
X. Ma ◽  
L. G. Feng
Keyword(s):  
Broadband Noise ◽  
Low Speed

ASSESSMENT OF MULTALL AS CFD CODE FOR THE ANALYSIS OF TUBE-AXIAL FANS

2021 ◽  
pp. 1-12
Author(s):  
Piero Danieli ◽  
Massimo Masi ◽  
Giovanni Delibra ◽  
Alessandro Corsini ◽  
Andrea Lazzaretto
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Velocity Distribution ◽  
High Speed ◽  
State Of The Art ◽  
Stable Operation ◽  
Pressure Curve ◽  
Analysis Tool ◽  
Low Speed ◽  
Axial Fans

Abstract This work deals with the application of the open source CFD code MULTALL to the analysis of tube-axial-fans. The code has been widely validated in the literature for high-speed turbomachine flows but not applied yet to low speed tutbomachines. The aim of this work is to assess the degree of reliability of MULTALL as a tool for simulating the internal flow in industrial axial-flow fan rotors. To this end, the predictions of the steady-state air flow field in the annular sector of a 315 mm tube-axial fan obtained by MULTALL 18.3 are compared with those obtained by two state-of-the-art CFD codes and experimental data of the global aerodynamic performance of the fan and the pitch-wise averaged velocity distribution downstream of the rotor. All the steady-state RANS calculations were performed on either fully structured hexahedron or hexa-dominant grids using classical formulations of algebraic turbulence models. The pressure curve and the trend of the aeraulic efficiency in the stable operation range of the fan predicted by MULTALL show very good agreement with both the experimental data and the other CFD results. Although the estimation of the fan efficiency predicted by MULTALL can be noticeably improved by the more sophisticated state-of-the-art CFD codes, the analysis of the velocity distribution at the rotor exit supports the use of MULTALL as a reliable CFD analysis tool for designers of low-speed axial fans.

Comparison between Measurements and Predictions of Fan Broadband Noise on a Low Speed Fan Rig

2010 ◽  
Vol 9 (3) ◽  
pp. 237-251 ◽  
Author(s):  
V. Jurdic ◽  
P. Joseph ◽  
A. Moreau ◽  
L. Enghardt
Keyword(s):  
Broadband Noise ◽  
Low Speed

Sound generation mechanism in low speed axial fans.

2010 ◽  
Vol 127 (3) ◽  
pp. 1837-1837 ◽  
Author(s):  
Stefano Bianchi ◽  
Alessandro Corsini ◽  
Anthony G. Sheard
Keyword(s):  
Generation Mechanism ◽  
Sound Generation ◽  
Low Speed ◽  
Axial Fans

Near‐ultrasound, broadband noise generated by low‐speed airflow over wires.

2010 ◽  
Vol 127 (3) ◽  
pp. 1781-1781
Author(s):  
W.C. Kirkpatrick Alberts ◽  
Kevin J. Sanchez ◽  
Mark A. Coleman ◽  
Josh Gabrielse ◽  
David A. Ligon
Keyword(s):  
Broadband Noise ◽  
Low Speed

scholarly journals Converged statistics for time-resolved measurements in low-speed axial fans using high-frequency response probes

2014 ◽  
Vol 54 ◽  
pp. 71-84 ◽  
Author(s):  
J.M. Fernández Oro ◽  
K.M. Argüelles Díaz ◽  
M. Rodríguez Lastra ◽  
M. Galdo Vega ◽  
B. Pereiras García
Keyword(s):  
Frequency Response ◽  
High Frequency ◽  
Time Resolved ◽  
Low Speed ◽  
High Frequency Response ◽  
Axial Fans ◽  
Time Resolved Measurements
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