THERMAL SCIENCE

International Scientific Journal

DESIGN OF A VERTICAL ANNULUS WITH MHD FLOW USING ENTROPY GENERATION ANALYSIS

ABSTRACT
Optimal design of a heat exchanger is one of the concerns of energy conversion engineers. In the present work, the mixed convection flow between two vertical concentric pipes with constant heat flux at the boundaries and MHD flow effects is considered. To determine the optimal design for such a heat exchanger, at first, the momentum and energy equations are simplified and solved analytically. Next, using entropy generation analysis and cost analysis, the operational costs due to entropy generation are estimated. It is concluded that with an increase in the Hartmann number, the energy costs increase. In addition, for two small deviations from the base radius ratio )2(=P including 9.1=P and 1.2=P , the changes in the energy cost are calculated. It is found that for 9.1=P the energy cost increases by 17.5% while for P = 2.1 the energy cost is reduced by 13.6 %.
KEYWORDS
PAPER SUBMITTED: 2012-10-17
PAPER REVISED: 2013-04-10
PAPER ACCEPTED: 2013-04-10
PUBLISHED ONLINE: 2013-04-21
DOI REFERENCE: https://doi.org/10.2298/TSCI121017038M
CITATION EXPORT: view in browser or download as text file
THERMAL SCIENCE YEAR 2013, VOLUME 17, ISSUE 4, PAGES [1013 - 1022]
REFERENCES
  1. Dağtekin, İ., Öztop, H.F., Şahin, A.Z., An analysis of entropy generation through a circular duct with different shaped longitudinal fins for laminar flow, International Journal of Heat and Mass Transfer, 48(2005), pp.171-181.
  2. Yilbas, B.S., Entropy analysis of concentric annuli with rotating outer cylinder, Int. J. Exergy, 1(2001), pp. 60-66.
  3. Mahmud, S., Fraser, R.A., Second law analysis of heat transfer and fluid flow inside a cylindrical annular space, Int. J. Exergy, 2(2002), pp. 322-329.
  4. Mahmud, S., Fraser, R.A., Analysis of entropy generation inside concentric cylindrical annuli with relative rotation, Int. J. Thermal Sciences, 42(2003), pp. 513-521.
  5. Tasnim, S.H., Mahmud, S., Mixed convection and entropy generation in a vertical annular space, Int. J. Exergy, 2(2002), pp. 373-379.
  6. Tasnim, S.H., Mahmud, S., Entropy generation in a vertical concentric channel with temperature dependent viscosity, Int. Commun. Heat Mass Transfer, 29(2002), pp. 907-918.
  7. Mirzazadeh, M., Shafaei, A., Rashidi, F., Entropy analysis for non-linear viscoelastic fluid in concentric rotating cylinders, Int. J. Thermal Sciences, 47(2008), pp. 1701-1711.
  8. Mahian, O., Mahmud, S., Zeinali Heris, S., Analysis of entropy generation between corotating cylinders using nanofluids, Energy 44(2012), pp. 438-446.
  9. Mahian , O., Mahmud , S., Zeinali Heris, S., Effect of uncertainties in physical properties on entropy generation between two rotating cylinders with nanofluids, ASME J. Heat Transfer,134(2012), pp. 101704.
  10. Jery, A.E., Hidouri, N., Magherbi, M., Brahim, A.B., Effect of an external oriented magnetic field on entropy generation in natural convection, Entropy, 12(2010), pp. 1391-1417.
  11. Salas, H., Cuevas, S., Haro, M.L., Entropy generation analysis of magnetohydrodynamic induction devices, J. Phys D: Appl Phys. 32(1999), pp.2605-2608.
  12. Ibanez, G., Cuevas, S., Haro, M. L., Optimization analysis of an alternate magnetohydrodynamic generator, Energy Conversion and Management, 43(2002), pp. 1757- 1771.
  13. Mahmud, S., Tasnim, S.H., Mamun, M.A.H., Thermodynamic analysis of mixed convection in a channel with transverse hydromagnetic effect, Int. J. Thermal Sci., 42(2003), pp. 731-740.
  14. Tasnim, S.H., Mahmud, S., Mamun, M.A.H., Entropy generation in a porous channel with hydromagnetic effect, Energy, 2(2002), pp. 300-308. 12
  15. Mahmud, S., Fraser, R.A., Mixed convection-radiation interaction in a vertical porous channel: Entropy generation, Energy, 28(2003), pp.1557-1577.
  16. Mahmud, S., Fraser, R.A., Magnetohydrodynamic free convection and entropy generation in a square porous cavity, Int. J. Heat Mass Transfer, 47(2004), pp. 3245-3256.
  17. Mahmud, S., Fraser, R.A., The thermagoustic irreversibility for a single-plate thermoacoustic system, Int. J. Heat Mass Transfer, 49(2006), pp. 3448-3461.
  18. Ibanez, G., Cuevas, S., Optimum wall conductance ratio in magnetoconvective flow in a long vertical rectangular duct, Int. J. Thermal Sci., 47(2008), pp. 1012-1019.
  19. Arikoglu, A., Ozkol , I., Komurgoz, G., Effect of slip on entropy generation in a single rotating disk in MHD flow, Appl Energy, 85(2008), pp. 1225-1236.
  20. AIboud, S., Saouli, S., Entropy analysis for viscoelastic magnetohydrodynamic flow over a stretching surface, Int. J. Non-Linear Mech, 45(2010), pp. 482-489.
  21. Mahian, O., Mahmud, S., Pop, I., Analysis of first and second laws of thermodynamics between two isothermal cylinders with relative rotation in the presence of MHD flow, Int. J. Heat Mass Transfer , 55 (2012), pp. 4808-4816.
  22. Mahian, O., Mahmud, S., Wongwises, S., Entropy generation between two rotating cylinders in the presence of MHD flow using nanofluids, Journal of Thermophysics and Heat transfer-AIAA, 27 (2013), pp. 161-169.
  23. Paoletti, S., Rispoli, F., Sciubba, E., Calculation of exergetic losses in compact heat exchanger passages, ASME AES, 10 (1980), pp. 21-29.
  24. Sahin, A.Z., Zubair, S.M., Al-Garni, A.Z., Kahraman, R. Effect of fouling on operational cost in pipe flow due to entropy generation, Energy Conversion & Management, 41 (2000), pp. 1485-1496.

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