مبدل دولوله‌ای مارپیچ پر شده از محیط متخلخل تحت شار حرارتی نامتقارن

نوع مقاله: پژوهشی

نویسندگان

دانشگاه سمنان

چکیده

در مقاله حاضر مبدل حرارتی دولوله­ای مارپیچ پر شده از محیط متخلخل که تحت شار حرارتی نامتقارن قرار دارد به صورت تحلیلی مورد مطالعه قرار می­گیرد. معادلات مومنتوم و انرژی به دستگاه مختصات گرمانو انتقال داده شده و سپس پروفیل­های سرعت و دما بر حسب توان­های انحنای بدون بعد به کمک روش اغتشاشات بدست می­آیند. همچنین کانتورهای سرعت و دما برای ارائه دید بهتر هندسه پیچیده مورد بررسی، ارائه می­شوند. نتایج مشخص می­سازند که پروفیل سرعت محوری به دلیل انحنای هندسه، نامقتارن می­باشد که شدت این عدم تقارن تابعی از انحنا است. همچنین نشان داده می­شود که عدد ناسلت با افزایش انحنا و همچنین افزایش نسبت شعاع لوله داخلی به لوله خارجی افزایش پیدا می­کند.

کلیدواژه‌ها


عنوان مقاله [English]

Porous-filled helical double-pipe heat exchanger under asymmetric heat flux

نویسندگان [English]

  • Maziar Dehghan
  • Nima Tirandaz
  • Mohammad Sadegh Valipour
چکیده [English]

A helical double-pipe heat exchanger filled with a porous material under asymmetric heat flux is studied analytically. Momentum and energy equations are transformed to the Germano’s coordinate and then expressions representing the velocity and temperature fields are obtained based on the powers of dimensionless curvature using perturbation analysis. To be more insightful, contours of velocity and temperature fields are presented. Results reveal an asymmetric axial velocity profile arising from the curved geometry. The Nusselt number increases with respect to the dimensionless curvature increment as well as the inner to outer radius ratio increase.

کلیدواژه‌ها [English]

  • Asymmetric heat flux
  • helical annulus
  • Analytical Solution
  • porous media
  • Forced convection

[1] D.A. Nield, and A.V. Kuznetsov, "Forced convection in a helical pipe filled with a saturated porous medium", International journal of heat and mass transfer, Vol. 47, NO. 24, November 2004, pp. 5175– 5180.
[2] A. Jamarani, M. Maerefat, and M.E. Nimvari, "Numerical study of heat transfer in double-tube heat exchanger filled with porous material in a turbulent fluid flow", Modares Mechanical Engineering, Vol. 16, NO. 3, 2016, pp. 173 – 184.
[3] A. Jamarani, M. Maerefat, and M.E. Nimvari, "Numerical investigation of nanofluid's effect on heat transfer in a pipe partially filled with porous material in a turbulent fluid flow", Modares Mechanical Engineering, Vol. 16, NO. 6, 2016, pp. 255 – 258.
[4] L. Cheng, and A.V. Kuznetsov, "Heat transfer in a laminar flow in a helical pipe filled with a fluid saturated porous medium", International journal of thermal sciences, Vol. 44, NO. 8, August 2005, pp. 787 – 798.
[5] L. Cheng, and A.V. Kuznetsov, "Investigation of laminar flow in a helical pipe filled with a fluid saturated porous medium", Journal of Mechanics - B/Fluids, Vol. 24, NO. 3, May 2005, pp. 338 – 352.
[6] A. Avramenko, and A.V. Kuznetsov, "Flow in a Curved Porous Channel with a Rectangular Cross Section", Journal of Porous Media, Vol. 11, NO. 3, 2008, pp. 241 – 246.
[7] S.M.H. Hashemi, S.A. Fazeli, and H. Shokouhmand, "Fully developed non-Darcian forced convection slip-flow in a micro-annulus filled with a porous medium: Analytical solution", Energy Conversion and Management, Vol. 52, NO. 2, February 2011, pp. 1054 – 1060.
[8] K. Hooman, and A.A. Ranjbar-Kani, "A perturbation based analysis to investigate forced convection in a porous saturated tube", Journal of Computational and Applied Mathematics, Vol. 162, NO. 2, January 2004, pp. 411 – 419.
[9] K. Hooman, "A perturbation solution for forced convection in a porous-saturated duct", Journal of computational and applied mathematics, Vol. 211, NO. 1, January 2002, pp. 57 – 66.
[10] M. Dehghan, M.S. Valipour, and S. Saedodin, "Perturbation analysis of the local thermal non-equilibrium condition in a fluid saturated porous medium bounded by an iso-thermal channel", Transport in porous media, Vol. 102, NO. 2, March 2014, pp. 139 – 152.
[11] M. Dehghan, M.T. Jamal-Abad, and S. Rashidi, "Analytical interpretation of the local thermal non-equilibrium condition of porous media imbedded in tube heat exchangers", Energy Conversion Management, Vol. 85, September 2014, pp. 264 – 271.
[12] M. Dehghan, S. Saedodin, and M.S. Valipour, "Perturbation methods in hydrodynamics of porous media", 2nd Iranian Conference on Heat and Mass Transfer-ICHMT, Semnan, Iran, November 2014.
[13] M. Dehghan, Y. Rahmani, S. Saedodin, M.S. Valipour, and D.D. Ganji, "HPM analysis of forced convection in metal foams in the presence of radiation heat transfer", Journal of Modeling in Engineering, 2015, accepted manuscript.

[14] M. Dehghan, Y. Rahmani, D.D. Ganji, S. Saedodin, M.S. Valipour, and S. Rashidi, "Convection–radiation heat transfer in solar heat exchangers filled with a porous medium: Homotopy perturbation method versus numerical analysis", Renewable Energy, Vol. 74, February 2015, pp. 448 – 455.
[15] M. Dehghan, M.S. Valipour, and S. Saedodin, "Temperature-dependent conductivity in forced convection of heat exchangers filled with porous media: a perturbation solution", Energy Conversion and Management, Vol. 91, February 2015, pp. 259 – 266.
[16] M. Germano, "On the effect of torsion on a helical pipe flow", Journal of Fluid Mechanics, Vol. 125, December 1989, pp. 1 – 8.
[17] M. Germano, "The Dean equations extended to a helical pipe flow", Journal of Fluid Mechanics, Vol. 203, June 1982, pp. 289 – 305.
[18] D.A. Nield, and A. Bejan, " Convection in Porous Media ", 3rd Ed., Springer, New York, February 2006.
[19] M. Dehghan, Y. Mahmoudi, M.S. Valipour, and S. Saedodin, "Combined Conduction-Convection-Radiation Heat Transfer of Slip Flow inside a Micro - channel Filled with a Porous Material", Transport in Porous Media, Vol. 108, NO. 2, June 2015, pp. 413 – 436.
[20] R.C. Xin, and M.A. Ebadian, "The effect of Prandtl numbers on local and average convective heat transfer in a helicoidal pipe", Journal of Heat Transfer, Vol. 119, NO. 3, August 1997, pp. 467 – 473.