بررسی تجربی ضریب درگ در سیلندرهای دایروی با چیدمان پشت سر هم در زوایای مختلف

نوع مقاله : علمی پژوهشی

نویسندگان

1 کارشناس ارشد، گروه مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه حکیم سبزواری، سبزوار

2 دکتری، گروه مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه حکیم سبزواری، سبزوار

3 استاد، گروه مهندسی مکانیک، دانشکده فنی و مهندسی، دانشگاه حکیم سبزواری، سبزوار

چکیده

 آرایش های زیادی برای قرار دادن استوانه ها در مجاورت یکدیگر وجود دارد. چیدمان سیلندرهای دایروی اعم از آرایش مجاور هم، پشت سرهم و متناوب در زوایای مختلف اخیرا توسط محققین مورد توجه قرار گرفته است. لذا در پژوهش حاضر، تغییرات ضریب پسا در سه سیلندر A، B و C با قطرهای 5/15، 3/21 و 31 میلیمتر در زوایای°0، °5، °10، °5/22، °45، °5/67 و °90 در دو نسبت فاصله 2 و 4 برابر قطر سیلندر اصلی در اعداد رینولدز مختلف (48000>Re>14700) به صورت تجربی بررسی شده است. نتایج بیانگر آن است که تغییرات ضریب پسا کاملاً به قطر استوانه ها و نسبت فاصله وابسته می باشد. تغییرات ضریب درگ در نسبت فاصله 2 برابر قطر سیلندر اصلی در زوایای مختلف، وابستگی کمی به تغییرات عدد رینولدز دارد. همچنین با افزایش قطر سیلندر پایین دست از شدت تاثیر عدد رینولدز بر تغییرات افزایشی ضریب درگ کاسته می شود. در 4=L/D ضریب پسا، حساسیت کمتری نسبت به تغییرات زاویه، به جز زاویه صفر درجه از خود نشان می دهد.

کلیدواژه‌ها


[1] Han, Z., Zhou, D., Gui, X., Flow past two tandem circular cylinders using Spectral element method, The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7), Shanghai, China, September 2-6,  pp. 546-554, (2012).
 
[2] Pouryoussefi, G., Mirzaei, M.A.S.O.U.D., Ardekani, M.A., Experimental investigation of force coefficients for groups of three and four circular cylinders subjected to a cross-flow, Mechanical and Aerospace Engineering Journal, Vol. 5, pp. 87-95, (2009).
 
[3] Meneghini, J.R., Saltara, F., Siqueira, C.D.L.R., Ferrari Jr, J.A., Numerical simulation of flow interference between two circular cylinders in tandem and side-by-side arrangements, Journal of Fluids and Structures, Vol. 15, pp. 327-350, (2001).
 
[4] Vu, H.C., Ahn, J., Hwang, J.H., Numerical simulation of flow past two circular cylinders in tandem and side-by-side arrangement at low Reynolds numbers, KSCE Journal of Civil Engineering, Vol. 20, pp. 1594-1604, (2016).
 
[5] Gao, Y., Etienne, S., Wang, X., Tan, S.K., Experimental study on the flow around two tandem cylinders with unequal diameters, Journal of Ocean University of China, Vol. 13, pp. 761-770, (2014).
 
[6] Zhao, M., Cheng, L., Teng, B., Liang, D., Numerical simulation of viscous flow past two circular cylinders of different diameters, Applied Ocean Research, Vol. 27, pp. 39-55, (2005).
[7] Fu, Y., Zhao, X., Wang, X., Cao, F., Computation of flow past an in-line oscillating circular cylinder and a stationary cylinder in tandem using a CIP-based model, Mathematical Problems in Engineering,  (2015).
 
[8] Yang, S., Yan, W., Wu, J., Tu, C., Luo, D., Numerical investigation of vortex suppression regions for three staggered circular cylinders, European Journal of Mechanics-B/Fluids, Vol. 55, pp. 207-214, (2016).
 
[9] Supradeepan, K., Roy, A., Characterisation and analysis of flow over two side by side cylinders for different gaps at low Reynolds number: a numerical approach, Physics of Fluids, Vol. 26, (2014).
 
[10] Ezadi Yazdi, M.J., Bak Khoshnevis, A., Comparing the wake behind circular and elliptical cylinders in a uniform current, SN Applied Sciences, Vol. 2(5), pp. 1-13, (2020).
 
[11] Ezadi Yazdi, M.J., Rad, A.S., Khoshnevis, A.B., Features of the flow over a rotating circular cylinder at different spin ratios and Reynolds numbers: Experimental and numerical study, The European Physical Journal Plus, Vo. 134(5), pp. 1-21, (2019).
 
[12] Yazdi, M.J.E., , Khoshnevis, A.B., Experimental study of the flow across an elliptic cylinder at subcritical Reynolds number, The European Physical Journal Plus, Vol. 133(12), pp. 533, (2018).
 
[13] Yadegari, M., Bak Khoshnevis, A., Numerical and Experimental study of characteristics of the wake produced behind an elliptic cylinder with trip wires, Iranian Journal of Science and Technology, Transactions of Mechanical Engineering, Vol. 45, pp. 265-285, (2021).
 
[14] Yadegari, M., An optimal design for S-shaped air intake diffusers using simultaneous entropy generation analysis and multi-objective genetic algorithm, The European Physical Journal Plus, Vol. 136(10), pp. 1-25, (2021).
 
[15] Yadegari, M., Bak Khoshnevis, A., A numerical study over the effect of curvature and adverse pressure gradient on development of flow inside gas transmission pipelines, Journal of the Brazilian Society of Mechanical Sciences and Engineering, Vol. 42(8), pp. 1-15, (2020).
 
[16] Yadegari, M., and Bak Khoshnevis, A., Investigation of entropy generation, efficiency, static and ideal pressure recovery coefficient in curved annular diffusers, The European Physical Journal Plus, Vol. 136(1), pp. 1-19, (2021).
 
[17] Wang, J.J., Zhang, P.F., Lu, S.F., Wu, K., Drag reduction of a circular cylinder using an upstream rod, Flow, Turbulence and Combustion, Vol. 76, pp. 83-101, (2006).
 
[18] Lee, S.J., Lee, S.I., and Park, C.W., Reducing the drag on a circular cylinder by upstream installation of a small control rod, Fluid Dynamics Research, Vol. 34, pp. 200-233, (2004).
 
[19] Yadegari, M., Bak Khoshnevis, A., Boloki, M., An experimental investigation of the effects of helical strakes on the characteristics of the wake around the circular cylinder, Iranian Journal of Science and Technology, Transactions of Mechanical Engineering, pp. 1-14, (2022).
 
[20] Bak Khoshnevis, A., Boloki, M., Yadegari, M., The investigation of the effect of the helical strakes' height on the cylinder wake, Journal of Solid and Fluid Mechanics, Vol. 10(1), pp. 223-236, (2020).
 
[21] Yadegari, M., Bak Khoshnevis, A., Entropy generation analysis of turbulent boundary layer flow in different curved diffusers in air-conditioning systems, The European Physical Journal Plus, Vol. 135(6), pp. 1-22, (2020).
 
[22] Yadegari, M., Bak Khoshnevis, A., Numerical study of the effects of adverse pressure gradient parameter, turning angle and curvature ratio on turbulent flow in 3D turning curved rectangular diffusers using entropy generation analysis, The European Physical Journal Plus, Vol. 135(7), pp. 1-21, (2020).   
 
[23] Cengel, Y.A., and Cimbala, J.M., Properties of fluids, Fluid Mechanics: Fundamentals and Applications, pp. 37-73, (2014).
 
[24] Munson, B.R., Young, D.F., Okiishi, T.H., and Huebsch, W.W., Fundamentals of Fluid Mechanics, John Wiley & Sons. Inc., USA, (2006).
 
[25] Achenbach, E., Experiments on the flow past spheres at very high Reynolds numbers, Journal of Fluid Mechanics, Vol. 54, pp. 565-575, (1972).
 
[26] Wang, J.J., Zhang, P.F., Lu, S.F., and Wu, K., Drag reduction of a circular cylinder using an upstream rod, Flow, Turbulence and Combustion, Vol. 76, pp. 83-101, (2006).
 
[27] Simiu E., Scanlan R.H., Wind Effect on Structures: Fundamentals and Design, John Wiley and Sons, New York, Vol. 688, (1996).
 
[28] Lam, K.M., Wong, P.T.Y., Ko, N.W.M., Interaction of flows behind two circular cylinders of different diameters in side-by-side arrangement, Experimental Thermal and Fluid Science, Vol. 7, pp. 189-201, (1993).