Free and Non-Free Vortex Design for Axial Fans with Circumferential Sweep through CFD Techniques

Document Type : Regular Article

Authors

1 Federal University of Itajubá, Itajubá, MG, 37500-903, Brazil

2 ECCI University, Bogotá, Cundinamarca, 111311, Colombia

10.47176/jafm.15.04.33209

Abstract

The sound generated by axial flow fans has become increasingly important in several industrial areas. These devices represent considerable noise sources that must be considered from the design stage. The scope of this research work is to present an axial fan design methodology based on the theory of the wing lift and to compare the aerodynamic and aeroacoustics behavior with the free vortex and the non-free vortex conditions. The effect of forward circumferential sweep on the rotor blades is analyzed in both conditions, which consists of a displacement in the tangential direction in the direction of rotor rotation. A cubic polynomial function is proposed for the construction of the blade geometry with circumferential sweep. It defines the center line of the blade and it is taken at 50% of the leading edge of each blade profile. The methodology for analyzing aeroacoustics behavior in fans is based on the integration of Computational Aeroacoustics and Computational Fluid Dynamics in order to analyze aerodynamic behavior, sound power level and sound pressure level at the preliminary design stage. It was verified that although both rotors present a similar aerodynamic behavior (the NFV rotor has a slightly lower performance), according to the analysis of local sound sources, the NFV rotor presents a slight decrease in the sound sources. It was also verified that the NFV rotor presents 2.2 dB less in sound pressure level than the FV rotor.

Keywords


Aguirre, C., R. Ramirez, W. de Oliveira and F. Avellan (2019). Numerical analysis for detecting head losses in trifurcations of high head in hydropower plants. Renewable Energy 131, 197-207.##
Albuquerque, R. (2006). Teoria da Asa de Sustentação Aplicada às Máquinas de Fluxo. Mechanical Engineering Institute, Federal University of Itajubá, Minas Gerais, Brazil. (In Portuguese).##
Ansys Inc. (2012). Ansys Fluent Theory guide. USA.##
Asghari, M., M. Mirzabozorg and M. Adami (2019). Aerodynamic optimization of the tangential stacking line of a transonic axial flow compressor rotor using genetic algorithm. Journal of the Brazilian Society of Mechanical Sciences and Engineering 41(37).##
Augustyn, O. P. (2013). Experimental and Numerical Analysis of Axial Flow Fans. Master Thesis, Faculty of Engineering at Stellenbosch University, South Africa, December.##
Ayar, A., R. Ambs, C. Capellmann, B. Schillemeit, M. Matthes. (2005). Prediction of Flow-Induced Noise in Automotive HVAC Systems Using a Combined CFD/CA Approach. SAE Technical Paper 2005-01-0509.##
Beiler, M. and T. Carolus (1999). Computation and Measurement of the Flow in Axial Flow Fans with Skewed Blades, ASME Journal of Turbomachinery 121, 59-66.##
Bran, R. and Z. Souza (1969). Máquinas de Fluxo: Bombas, Ventiladores e Turbinas. Livro Técnico S.A. Rio de Janeiro, Brazil. (In Portuguese)."##
Camacho, R. and J. Barbosa (2005). The boundary Element Method Applied to Incompressible Viscous Fluid Flow. Journal of the Brazilian Society of Mechanical Sciences and Engineering 27(4), pp. 456–462.##
Camacho, R. and N. Manzanares Filho (2005). Source Wake Model for Cascades of Axial Flow Turbomachines. Journal of the Brazilian Society of Mechanical Sciences and Engineering 27(3), pp. 288–299.##
Carolus, T. and M. Beiler (1997). Skewed blades in low pressure fans: a survey of noise reduction mechanisms. American Institute of Aeronautics and Astronautics, 97, 1591.##
Castilho, L., R. Ramirez Camacho, E. da Silva (2016). Optimized Design of Linear Cascades For Turbomachinery Applications. Journal of the Brazilian Society of Mechanical Sciences and Engineering 38(3), pp. 813–825.##
Corsini, A. and F. Rispoli (2004). Using sweep to extend the stall-free operational range in axial fan rotors. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 218: 129.##
Cox-Stouffer, S. (1997). Numerical Simulation of Injection and Mixing in Supersonic Flow. Ph. D. thesis, Virginia Polytechnic Institute and State University.##
Croaker, P., A. Skvortsov and N. Kessissoglou. (2011). A simple approach to estimate flow-induced noise from steady state CFD. Australian Acoustical Society Conference 2011, 451-458.##
Curle, N. (1955). The Influence of Solid Boundaries upon Aerodynamic Sound, Proceedings of the Royal Society of London Series A, 231, 505-514.##
Dachuan, X., W. Haifeng, Q. Xiaoli, Y. Yongsheng, S. Yu and Z. Fang (2019). Application of Arbitrary Vortex Method in Wind Tunnel Axial Fan Design. IOP Conference Series: Materials Science and Engineering, 616, 012006.##
Dozolme, A., H. Metwally and T. Marchal (2006). Electronics Cooling Fan Noise Prediction. Therminic 2006, Nice, France. TIMA Editions, 75-79.##
Eck, B. (1973). Fans - Design and Operation of Centrifugal, Axial-flow and Cross-flow Fans. First edition. Pergamon Press, Oxford, New York.##
Guédel, A., M. Robitu, N. Descharmes, D. Amor and J. Guillard (2012). Prediction of the blade trailing-edge noise of an axial flow fan. ASME Turbo Expo 2011. Paper GT2011-45256, Vancouver, Canada.##
Herold, G., F. Zenger and E. Sarradj (2017). Influence of blade skew on axial fan component noise. International Journal of Aeroacoustics 16(4–5) 418–430.##
Horváth, C. and J. Vad (2009). Broadband noise source model acoustical investigation on unskewed and skewed axial flow fan rotor cascades; Conference on Modelling Fluid Flow (CMFF’09). The 14th International Conference on Fluid Flow Technologies. Budapest, Hungary, September 9-12.##
Hurault, J., S. Kouidri, F. Bakir and R. Rey (2010). Experimental and numerical study of the sweep effect on three-dimensional flow downstream of axial flow fans. Journal Flow Measurement and Instrumentation. 21, 155-165.##
ISO 13347-3 (2004). Industrial fans - Determination of fan sound power levels under standardized laboratory conditions - Part 3: Enveloping surface methods, International Organization for Standardization, Geneva.##
Junger, C. (2019). Computational aeroacoustics for the characterization of noise sources in rotating systems. Doctoral theses. Vienna University of Technology Faculty of Mechanical and Industrial Engineering.##
Khondge, A. D, S. Sovani, S. Kim, S. Guzy and A. Farag (2005). On Predicting Aeroacoustic Performance of Ducts with Broadband Noise Source Models. SAE Paper, 2005-01-249.##
Krömer, F. and S. Becker (2018). Experimental investigation of the off-design sound emission of low-pressure axial fans with different fan blade skew. Conference Proceedings of Euronoise.##
Krömer, F., F. Czwielong and S. Becker (2019). Experimental investigation of the sound emission of skewed axial fans with leading-edge serrations. 25th AIAA/CEAS Aeroacoustics Conference, AIAA 2019-2735.##
Kwedikha, A. (2009). Aerodynamic effects of blade sweep and skew applied to rotors of axial flow turbomachinery. Ph.D. Thesis. Budapest University of Technology and Economics Faculty of Mechanical Engineering Department of Fluid Mechanics. Budapest.##
Lighthill, M. (1952). On sound generated aerodynamically, I. General theory. Proceedings of the Royal Society A 211, 564–587.##
Magne, S., S. Moreau and A. Berry (2015). Subharmonic tonal noise from backflow vortices radiated by a low-speed ring fan in uniforminlet flow. Journal of the Acoustical Society of America 137, 228–237##
Masi, M. and A. Lazzaretto (2017). Preliminary investigation on the effect of the modification of the sweep angle at the blade tip of forward swept axial fans. Proceedings of ASME Turbomachinery Technical Conference and Exposition GT 2017. June 26-30, Charlotte, NC, USA.##
Masi, M., A. Lazzaretto and S. Castegnaro (2018). Effectiveness of Blade Forward Sweep In A Small Industrial Tube-Axial Fan. Conference paper Fan 2018. Darmstadt, Germany, 18 – 20 April.##
Masi, M., S. Castegnaro and A. Lazzaretto (2016). Forward sweep to improve the efficiency of rotor-only tube-axial fans with controlled vortex design Blades. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy 230(5), 512-520.##
Mohamud, O. M. and P. Johnson. (2006). Broadband noise source models as aeroacoustics tools in designing low NVH HVAC ducts. SAE Technical Paper 2006-01-1192.##
Mota, P. (2018). Estudo Aeroacústico Numérico e Experimental de Ventilador Axial. Master’s thesis, Federal University of Itajubá, Minas Gerais, Brazil. (In Portuguese).##
Proudman, I. (1952). The generation of noise by isotropic turbulence. Proceedings of the Royal Society of London Series A, 214119,132.##
Roffi, M., F. Ferreira and A. de Almeida (2017). Comparison of different cooling fan designs for electric motors, 2017 IEEE International Electric Machines and Drives Conference (IEMDC), 1-7.##
Santos, Roberto M. Moura (1995). Ruído de helices: Mecanismos de geração e modelagem dos tons discretos. Master’s thesis, Federal University of Rio de Janeiro, Brazil. (In Portuguese).##
Sarkar, S. and M. Hussaini. (1993). Computation of the Sound Generated by Isotropic Turbulence, NASA Contract Report No. 93-74, NASA Langley Research Center, Hampton VA 24681.##
Sarmiento, A. (2013). Desenvolvimento de uma metodologia para o projeto aerodinâmico de rotores axiais reversíveis de ventiladores de jato de túneis rodoviários. Master’s thesis, Federal University of Itajubá, Minas Gerais, Brazil. (In Portuguese).##
Sarmiento, A., R. Ramirez and W. de Oliveira (2020). Performance Analysis of Radial-Inflow Turbine of ORC: New Combined Approach of Preliminary Design and 3D CFD Study. Journal of Mechanical Science and Technology 34(6), 2403–2422.##
Sarmiento, A., R. Ramirez, W. de Oliveira, V. Gutiérrez, M. Murthi and N. Diaz (2021). Design and off-design performance improvement of a radial-inflow turbine for ORC applications using metamodels and genetic algorithm optimization. Applied Thermal Engineering 183(2), 116197.##
Sarmiento, A., W. Oliveira and R. Camacho, (2017). Influence of the vortex design method in the performance characteristics of reversible axial rotors. Journal of the Brazilian Society of Mechanical Sciences and Engineering 39, 1575–1588.##
Suzuki, S., Y. Ugai and K. Komatsu (1985). A study on noise reduction of axial flow fans. In Proceedings Inter-noise 85 (München, Germany), 371-374.##
Vad, J. (2011). Blade Sweep Applied to Axial Flow Fan Rotors of Controlled Vortex Design. Doctoral Thesis Hungarian Academy of Sciences. Budapest.##
Vad, J. (2012). Incorporation of forward blade sweep in preliminary controlled vortex design of axial flow rotors. Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy, 226(4), 462-478.##
Vad, J., Halász G. and Benedek T. (2015). Efficiency gain of low-speed axial Flow rotors due to forward sweep. Proceedings of the Institution of Mechanical Engineers, Part A: Journal Power and Energy 229(1) 16–23.##
Wadia, A., P. Szucs and D. Crall (1998). Inner working of aerodynamic sweep. Journal of Turbomachinery. ASME paper 97-GT-401.##
Wallis, R. (1983). Axial Flow Fans and Ducts. First edition. John Willey & Sons, Inc.##
Yahya, S. (1983). Turbines, Compressors and Fans. Tata McGraw-Hill Publishing Company Limited.##
Yang, L. (2016). Investigation of blade tip of axial rotor with part-span forward skew. Proceedings of the 2015 International Conference (MME2015- Mechanics and Mechanical Engineering), 414 - 420. ##
Younsi, M. and J. Lavedrine (2015). Unsteady Flow and Acoustic Behaviour of an Axial Fan: Numerical and Experimental Investigations. Proceedings of 11th European Conference on Turbomachinery Fluid dynamics & Thermodynamics ETC11, March 23-27, Madrid, Spain.##
Zenger, F. and S. Becker (2016). Fluid Mechanical and Acoustic Characterization of Low-Pressure 3Axial Fans with different Blade Skew. 18th International Symposium on the Application of Laser and Imaging Techniques to Fluid Mechanic. Portugal. July 4 – 7.##
Volume 15, Issue 4 - Serial Number 66
July and August 2022
Pages 1017-1034
  • Received: 17 July 2021
  • Revised: 24 March 2022
  • Accepted: 25 March 2022
  • First Publish Date: 01 July 2022