نوع مقاله : مقالة‌ تحقیقی‌ (پژوهشی‌)

نویسنده

پژوهشکده علوم و فناوری هوایی، پژوهشگاه هوافضا، وزارت علوم، تحقیقات و فناوری، تهران، ایران

چکیده

در این مقاله طراحی دیفیوزر یک تونل باد زیر‌صوت مکشی که سه فن محوری نیروی رانش آن را تأمین می-کنند، به کمک دینامیک سیالات عددی مورد توجه قرار گرفته است. اتاق آزمون تونل باد یاد شده به ابعاد cm140x cm195 است. برای مدل‌سازی فن محوری یاد شده که شامل 10 پره روتور و 13 پره استاتور می-باشد، از روش‌‌ مدل‌سازی سه بعدی پره‌ها استفاده شده است. در روند طراحی دیفیوزر و مدل‌سازی تونل باد از مدل‌سازی سه‌بعدی پره‌ها استفاده شده است. این روش به بهترین شیوه اثرات چرخش جریان را مدل می‌کند. در بخش طراحی دیفیوزر سعی شد تا با بررسی حالات مختلف هندسی، دیفیوزری با بهترین عملکرد انتخاب شود. طرح نهایی دیفیوزری با زاویه مخروط معادل 4 درجه و طرح دایروی می‌باشد. همچنین نشان داده شد که طرح دایروی در مقایسه با طرح‌های سه‌گوش و محاطی عملکرد بهتری از لحاظ افت فشار کل تونل باد و دبی عبوری از آن را دارا می‌باشد.

کلیدواژه‌ها

عنوان مقاله [English]

Design of a Diffuser for a Subsonic Wind Tunnel Using CFD

نویسنده [English]

  • Zoheir Saboohi

Aerospace Research Institute, Ministry of Science Research and Technology, Tehran, IRAN

چکیده [English]

In this paper, the design of a diffuser for a suction type subsonic wind tunnel equipped with three axial fans has been taken into account by CFD. The tunnel test section has a 140 cm height and 195cm width. For numerical modeling the axial fans that contains 10 rotor blades and 13 stator blades 3D modeling to simulate the impeller have been used. The 3D modeling to simulate the impeller method provides an adequate means for simulating the swirl effects of air flow. The best geometrical characteristics have been selected for designing the optimal performance for the diffuser. The final design includes a circular diffuser which incorporates a 4 degree equivalent cone angle. This study also suggests that the circular scheme is superior to the triangular and fitted design aspect of the total pressure loss and the volumetric flow rate.

کلیدواژه‌ها [English]

  • Wind tunnel
  • Computational fluid dynamics
  • Diffuser
  • Axial Fan
  • 3D modeling to simulate the impeller
[1]   Chang C.H. and Meroney R.N., “The Effect of Surroundings with Different Separation Distances on Surface Pressures on Low-Rise Buildings,” Journal of Wind Engineering and Industrial Aerodynamics, v. 91, n. 8, 2003, pp. 1039-1050.
[2]   Blocken B. and Carmeliet J., “A Review of Wind-Driven Rain Research in Building Science”, Journal of Wind Engineering and Industrial Aerodynamics, v. 92, n. 13, 2004,  pp. 1079-1130.
[3]   Sicot, C., Deliancourt, F., Boree, J., Aguinaga, S. and Bouchet, J.P., “Representativeness of Geometrical Details During Wind Tunnel Tests. Application to Train Aerodynamics in Crosswind Conditions”, Journal of Wind Engineering and Industrial Aerodynamics, v.177, 2018, pp.186-196.
[4]   Bayati, I., Belloli, M., Bernini, L. and Zasso, A., “Aerodynamic Design Methodology for Wind Tunnel Tests of Wind Turbine Rotors”, Journal of Wind Engineering and Industrial Aerodynamics, v. 167, 2017, pp.217-227.
[5]   Rae, W.H. and Pope, A., Low-speed wind tunnel testing (No. BOOK), John Wiley, 1984.
[6]   Meroney R.N., Leitl B.M., Rafailidis S. and Schatzmann, M., “Wind-Tunnel and Numerical Modeling of Flow and Dispersion about Several Building Shapes”, Journal of Wind Engineering and Industrial Aerodynamics, v. 81, 1999, pp. 333-345.
[7]   Gordon R., and Imbabi M.S., “CFD Simulation and Experimental Validation of a New Closed Circuit Wind/Water Tunnel Design,” Journal of Fluids Engineering – Transactions of the ASME, v. 120, n. 2, 1998, pp. 311-318.
[8]   Ghani, S.A.A.A., Aroussi, A. and Rice, E., “Simulation of Road Vehicle Natural Environment in a Climatic Wind Tunnel”, Simulation Practice and Theory, v. 8, n. 6, 2001, pp. 359-375.
[9]   Moonen P., Blocken B., Carmeliet J., “Indicators for the Evaluation of Wind Tunnel Test Section Flow Quality and Application to a Numerical Closed-Circuit Wind Tunnel”, International Journal of Wind Engineering and Industrial Aerodynamics, v. 95, 2007, pp.1289-1314.
[10] Zehrung, C.A.,Comparative Analysis of a Low-Speed Wind Tunnel Designed for Renewable Energy Applications, (M.Sc. Thesis), Purdue University, 2011.
[11] Moonen, P., Blocken, B., Roels, S., Carmeliet J., “Numerical Modeling of the Flow Condition in a Closed-Circuit Low-Speed Wind Tunnel” International Journal of Wind Engineering and Industrial Aerodynamics, v. 94, 2006, pp.699-723.
[12] Mathew, J., Design, Fabrication, and Characterization of an Anechoic Wind Tunnel Facility, (Ph.D. Thesis), University of Florida, 2006.
[13] Eckert, W.T., Mort, K.K. and Jope, J., “Aerodynamic Design Guidelines and Computer Program for Estimation of Subsonic Wind Tunnel Performance”, NASA TN D-8243, 1976.
[14] Bender, T.J., Bergstrom, D.J. and Rezkallah, K.S., “A Study on the Effects of Wind Intake Flow Rate of a Cooling Tower. Part 3: Numerical Study”, Journal of Wind Engineering andIndustrial Aerodynamics, v. 64, 1996, pp. 81-100.
[15] Senol S., and Cinar A., “Design and Flow Simulation of an Opn Circuit Wind Tunnel,” Engine. Soft International Conference, 2009, pp. 11-14.
[16] Thiart, G.D., A Numerical Procedure for Predicting the Effects of Distorted Inflow Conditions on the Performance of Axial Flow Fans, (PhD Thesis), Department of Mechanical Engineering, University of Stellenbosch, 1990.
[17] Fluent, A., Fluent 12, Theory guide, 2017.
[18] LTG Axial-Flow and Centrifugal Fans, LTG Incorpated, Technical Brochure.
[19] British Standards Institution, Fans for General Purposes, Part 1, Methods for Testing Performance, BS 848, 1997.
[20] van der Spuy, S.J., von Backstrom, T.W. and Kroger, D.G., “An Evaluation of Simplified Methods to Model the Performance of Axial Flow Fan Arrays”, R & D Journal of the South African Institution of Mechanical Engineering, v. 26, 2010, pp. 12-20.
[21] Buice, C.U., Experimental Investigation of Flow through an Asymmetric Plane Diffuser, (Ph.D. thesis), Stanford University, Stanford, 1997.