Experimental Study of Heat Transfer to Flowing Air inside a Circular Tube with Longitudinal Continuous and Interrupted Fins

ABSTRACT

Experimental investigations have been performed to determine the detailed module-by-module pressure drop and heat transfer coefficient of turbulent flow inside a circular finned tube. The tubes are provided with longitudinal fins continuous or interrupted in the stream wise direction by arranging them both in a staggered and in-line manner. Experiments are carried out for two different fin geometries, with two numbers of fins (N = 6 and 12). All tested finned tubes have 16 modules each with length equal to the tube diameter (L = D = 30 mm). The thermal boundary condition considered here, is a uniform heat flux. The module-by-module heat transfer coefficient is found to vary only in the first modules, and then attained a constant thermally periodic fully developed value after eight to twelve modules. The results also showed that in the periodic hydrodynamic fully developed region, the value of the pressure drop along the tube with continuous fins is greater than that of the in-line arrangement, and lower than that of the staggered arrangement. Furthermore, the results showed that in the periodic fully developed region, the tube with continuous fins produces a greater value of the heat transfer coefficients than that the tube with interrupted fins, especially through a high range of Reynolds number (5 × 104 > Re > 2 × 104). The tube with Staggered arrangement of fins produces a greater value of the heat transfer coefficient than the tube with continuous fins and the in-line arrangement finned tube at low Reynolds number (Re < 1.2 × 104).). It was found that the fins efficiency is greater than 90 percent; in the worst case (maximum Reynolds number with continuous fins tube).

Experimental investigations have been performed to determine the detailed module-by-module pressure drop and heat transfer coefficient of turbulent flow inside a circular finned tube. The tubes are provided with longitudinal fins continuous or interrupted in the stream wise direction by arranging them both in a staggered and in-line manner. Experiments are carried out for two different fin geometries, with two numbers of fins (N = 6 and 12). All tested finned tubes have 16 modules each with length equal to the tube diameter (L = D = 30 mm). The thermal boundary condition considered here, is a uniform heat flux. The module-by-module heat transfer coefficient is found to vary only in the first modules, and then attained a constant thermally periodic fully developed value after eight to twelve modules. The results also showed that in the periodic hydrodynamic fully developed region, the value of the pressure drop along the tube with continuous fins is greater than that of the in-line arrangement, and lower than that of the staggered arrangement. Furthermore, the results showed that in the periodic fully developed region, the tube with continuous fins produces a greater value of the heat transfer coefficients than that the tube with interrupted fins, especially through a high range of Reynolds number (5 × 104 > Re > 2 × 104). The tube with Staggered arrangement of fins produces a greater value of the heat transfer coefficient than the tube with continuous fins and the in-line arrangement finned tube at low Reynolds number (Re < 1.2 × 104).). It was found that the fins efficiency is greater than 90 percent; in the worst case (maximum Reynolds number with continuous fins tube).

KEYWORDS

Internal Flow; Turbulent Flow; Heat Transfer; Interrupted and Continuous Fins; Fin Analysis

Internal Flow; Turbulent Flow; Heat Transfer; Interrupted and Continuous Fins; Fin Analysis

Cite this paper

El-Sayed, S. , EL-Sayed, S. and Saadoun, M. (2012) Experimental Study of Heat Transfer to Flowing Air inside a Circular Tube with Longitudinal Continuous and Interrupted Fins.*Journal of Electronics Cooling and Thermal Control*, **2**, 1-16. doi: 10.4236/jectc.2012.21001.

El-Sayed, S. , EL-Sayed, S. and Saadoun, M. (2012) Experimental Study of Heat Transfer to Flowing Air inside a Circular Tube with Longitudinal Continuous and Interrupted Fins.

References

[1] I. M. Rustom and H. M. Soliman, “Numerical Analysis of Laminar Forced Convection in the Entrance Region of Tubes with Longitudinal Internal Fins,” ASME Journal of Heat Transfer, Vol. 110, No. 2, 1988, pp. 310-313. doi:10.1115/1.3250485

[2] A. Campo and J. C. Morales, “Analysis/Numerical Prediction of the Three-Dimensional Temperature Variation in Tube Having Stream Wise Internal Fins,” Journal of Numerical Heat Transfer, Part A: An International Journal of Computation and Methodology, Vol. 23, No. 3, 1993, pp. 319-339. doi:10.1080/10407789308913675

[3] C. Prakash and Y. D. Liu, “Analysis of Laminar Flow and Heat Transfer in the Entrance Region of an Internally Finned Circular Tubes,” ASME Journal of Heat Transfer, Vol. 107, No. 1, 1985, pp. 84-91. doi:10.1115/1.3247407

[4] D. Choudhury and S. V. Patankar, “Analysis of Laminar Flow and Heat Transfer in Tubes with Radial Internal Fins,” Proceedings of the 23rd National Heat Transfer Conference, Denver, 1985, pp. 57-64.

[5] N. H. Hu and Y. P. Chang, “Optimization of Finned Tu- bes for Heat Transfer in Laminar Flow,” ASME Journal of Heat Transfer, Vol. 95, No. 3, 1973, pp. 332-338. doi:10.1115/1.3450060

[6] J. H. Masliyah and K. N. Nandakumer, “Heat Transfer in Internally Finned Tubes,” ASME Journal of Heat Transfer, Vol. 98, No. 5, 1976, pp. 257-261. doi:10.1115/1.3450528

[7] H. M. Soliman, T. S. Chau and A. C. Trupp, “Analysis of Laminar Heat Transfer in Internally Finned Tubes with Uniform outside Wall Temperature,” ASME Journal of Heat Transfer, Vol. 102, No. 4, 1980, pp. 598-604. doi:10.1115/1.3244358

[8] S. V. Patankar, M. Ivanovic and E. M. Sparrow, “Analysis of Turbulent Flow and Heat Transfer in Internally Finned Tubes and Annuli,” ASME Journal of Heat Transfer, Vol. 101, No. 1, 1979, pp. 29-37. doi:10.1115/1.3450925

[9] N.-H. Kim and R. L. Webb, “Analytic Prediction of the Friction and Heat Transfer for Turbulent Flow in Axial Internal Fin Tubes,” ASME Journal of Heat Transfer, Vol. 115, No. 3, 1993, pp. 553-559. doi:10.1115/1.2910723

[10] E. M. Sparrow, B. R. Baliga and S. V. Patankar, “Heat Transfer and Fluid Analyses of Interrupted Wall Channels, with Application to Heat Exchangers,” ASME Journal of Heat Transfer, Vol. 99, No. 1, 1977, pp. 4-11. doi:10.1115/1.3450654

[11] E. M. Sparrow and C. H. Liu, “Heat Transfer, Pressure Drop and Performance Relationships for In-Line, Staggered, and Continuous Plate Heat Exchangers,” International Journal of Heat and Mass Transfer, Vol. 22, No. 12, 1979, pp. 1613-1625. doi:10.1016/0017-9310(79)90078-4

[12] A. L. London and R. K. Shah, “Offset Rectangular Plate- Fin Surface-Heat Transfer and Flow Friction Characteristics,” ASME Journal of Engineering for Power, Vol. 90, 1968, pp. 218-228.

[13] H. M. Joshi and R. L. Webb, “Heat Transfer and Friction in the Offset Stripfin Heat Exchanger,” International Journal of Heat and Mass Transfer, Vol. 30, No. 1, 1987, pp. 69-84. doi:10.1016/0017-9310(87)90061-5

[14] S. V. Patankar and C. Prakash, “An analysis of the Effect of Plate Thickness on Laminar Flow and Heat Transfer in Interrupted-Plate Passage,” International Journal of Heat and Mass Transfer, Vol. 24, No. 11, 1981, pp. 1801-1810. doi:10.1016/0017-9310(81)90146-0

[15] K. M. Kelkar and S. V. Patankar, “Numerical Prediction of Heat Transfer and Fluid Flow in Rectangular Offset-Fin Arrays,” Journal of Numerical Heat Transfer, Part A: Applications: An International Journal of Computation and Methodology, Vol. 15, No. 2, 1989, pp. 149- 164. doi:10.1080/10407788908944682

[16] H. M. Joshi and R. L. Webb, “Heat Transfer and Friction in the Offset Strip-Fin Heat Exchanger,” International Journal of Heat and Mass Transfer, Vol. 30, No. 1, 1987, pp. 69-84. doi:10.1016/0017-9310(87)90061-5

[17] K. M. Kelkar and S. V. Patankar, “Numerical Prediction of Fluid Flow and Heat Transfer in a Circular Tube with Longitudinal Fins Interrupted in Stream Wise Direction,” ASME Journal of Heat Transfer, Vol. 112, No. 2, 1990, pp. 342-348. doi:10.1115/1.2910383

[18] X. Liu and M. K. Jensen, “Geometry Effects on Turbulent Flow and Heat Transfer in Internally Finned Tubes,” ASME Journal of Heat Transfer, Vol. 123, No. 6, 2001, pp. 1035-1044. doi:10.1115/1.1409267

[19] S. K. Saha and P. Langille, “Heat Transfer and Pressure Drop Characteristics of Laminar Flow through a Circular Tube with Longitudinal Strip Inserts under Uniform Wall Heat Flux,” ASME Journal of Heat Transfer, Vol. 124, No. 3, 2002, pp. 421- 432. doi:10.1115/1.1423907

[20] O. Zeitoun and A. S. Hegazy, “Heat Transfer for Laminar Flow Internally Finned Pipes with Different Fin Heights and Uniform Wall Temperature,” Journal of Heat and Mass Transfer, Vol. 40, No. 3-4, 2004, pp. 253-259. doi:10.1007/s00231-003-0446-8

[21] W. M. Kays, “Convective Heat and Mass Transfer,” Mc- Graw-Hill, Boston, 1966.

[22] W. M. Kays and H. G. Perkins, “Handbook of Heat Transfer,” McGraw-Hill, Boston, 1972.

[23] M. N. Ozisik, “Basic Heat Transfer,” McGraw-Hill, Boston, 1977.

[24] F. M. White, “Heat Transfer,” Addison-Wesley, Boston, 1984.

[1] I. M. Rustom and H. M. Soliman, “Numerical Analysis of Laminar Forced Convection in the Entrance Region of Tubes with Longitudinal Internal Fins,” ASME Journal of Heat Transfer, Vol. 110, No. 2, 1988, pp. 310-313. doi:10.1115/1.3250485

[2] A. Campo and J. C. Morales, “Analysis/Numerical Prediction of the Three-Dimensional Temperature Variation in Tube Having Stream Wise Internal Fins,” Journal of Numerical Heat Transfer, Part A: An International Journal of Computation and Methodology, Vol. 23, No. 3, 1993, pp. 319-339. doi:10.1080/10407789308913675

[3] C. Prakash and Y. D. Liu, “Analysis of Laminar Flow and Heat Transfer in the Entrance Region of an Internally Finned Circular Tubes,” ASME Journal of Heat Transfer, Vol. 107, No. 1, 1985, pp. 84-91. doi:10.1115/1.3247407

[4] D. Choudhury and S. V. Patankar, “Analysis of Laminar Flow and Heat Transfer in Tubes with Radial Internal Fins,” Proceedings of the 23rd National Heat Transfer Conference, Denver, 1985, pp. 57-64.

[5] N. H. Hu and Y. P. Chang, “Optimization of Finned Tu- bes for Heat Transfer in Laminar Flow,” ASME Journal of Heat Transfer, Vol. 95, No. 3, 1973, pp. 332-338. doi:10.1115/1.3450060

[6] J. H. Masliyah and K. N. Nandakumer, “Heat Transfer in Internally Finned Tubes,” ASME Journal of Heat Transfer, Vol. 98, No. 5, 1976, pp. 257-261. doi:10.1115/1.3450528

[7] H. M. Soliman, T. S. Chau and A. C. Trupp, “Analysis of Laminar Heat Transfer in Internally Finned Tubes with Uniform outside Wall Temperature,” ASME Journal of Heat Transfer, Vol. 102, No. 4, 1980, pp. 598-604. doi:10.1115/1.3244358

[8] S. V. Patankar, M. Ivanovic and E. M. Sparrow, “Analysis of Turbulent Flow and Heat Transfer in Internally Finned Tubes and Annuli,” ASME Journal of Heat Transfer, Vol. 101, No. 1, 1979, pp. 29-37. doi:10.1115/1.3450925

[9] N.-H. Kim and R. L. Webb, “Analytic Prediction of the Friction and Heat Transfer for Turbulent Flow in Axial Internal Fin Tubes,” ASME Journal of Heat Transfer, Vol. 115, No. 3, 1993, pp. 553-559. doi:10.1115/1.2910723

[10] E. M. Sparrow, B. R. Baliga and S. V. Patankar, “Heat Transfer and Fluid Analyses of Interrupted Wall Channels, with Application to Heat Exchangers,” ASME Journal of Heat Transfer, Vol. 99, No. 1, 1977, pp. 4-11. doi:10.1115/1.3450654

[11] E. M. Sparrow and C. H. Liu, “Heat Transfer, Pressure Drop and Performance Relationships for In-Line, Staggered, and Continuous Plate Heat Exchangers,” International Journal of Heat and Mass Transfer, Vol. 22, No. 12, 1979, pp. 1613-1625. doi:10.1016/0017-9310(79)90078-4

[12] A. L. London and R. K. Shah, “Offset Rectangular Plate- Fin Surface-Heat Transfer and Flow Friction Characteristics,” ASME Journal of Engineering for Power, Vol. 90, 1968, pp. 218-228.

[13] H. M. Joshi and R. L. Webb, “Heat Transfer and Friction in the Offset Stripfin Heat Exchanger,” International Journal of Heat and Mass Transfer, Vol. 30, No. 1, 1987, pp. 69-84. doi:10.1016/0017-9310(87)90061-5

[14] S. V. Patankar and C. Prakash, “An analysis of the Effect of Plate Thickness on Laminar Flow and Heat Transfer in Interrupted-Plate Passage,” International Journal of Heat and Mass Transfer, Vol. 24, No. 11, 1981, pp. 1801-1810. doi:10.1016/0017-9310(81)90146-0

[15] K. M. Kelkar and S. V. Patankar, “Numerical Prediction of Heat Transfer and Fluid Flow in Rectangular Offset-Fin Arrays,” Journal of Numerical Heat Transfer, Part A: Applications: An International Journal of Computation and Methodology, Vol. 15, No. 2, 1989, pp. 149- 164. doi:10.1080/10407788908944682

[16] H. M. Joshi and R. L. Webb, “Heat Transfer and Friction in the Offset Strip-Fin Heat Exchanger,” International Journal of Heat and Mass Transfer, Vol. 30, No. 1, 1987, pp. 69-84. doi:10.1016/0017-9310(87)90061-5

[17] K. M. Kelkar and S. V. Patankar, “Numerical Prediction of Fluid Flow and Heat Transfer in a Circular Tube with Longitudinal Fins Interrupted in Stream Wise Direction,” ASME Journal of Heat Transfer, Vol. 112, No. 2, 1990, pp. 342-348. doi:10.1115/1.2910383

[18] X. Liu and M. K. Jensen, “Geometry Effects on Turbulent Flow and Heat Transfer in Internally Finned Tubes,” ASME Journal of Heat Transfer, Vol. 123, No. 6, 2001, pp. 1035-1044. doi:10.1115/1.1409267

[19] S. K. Saha and P. Langille, “Heat Transfer and Pressure Drop Characteristics of Laminar Flow through a Circular Tube with Longitudinal Strip Inserts under Uniform Wall Heat Flux,” ASME Journal of Heat Transfer, Vol. 124, No. 3, 2002, pp. 421- 432. doi:10.1115/1.1423907

[20] O. Zeitoun and A. S. Hegazy, “Heat Transfer for Laminar Flow Internally Finned Pipes with Different Fin Heights and Uniform Wall Temperature,” Journal of Heat and Mass Transfer, Vol. 40, No. 3-4, 2004, pp. 253-259. doi:10.1007/s00231-003-0446-8

[21] W. M. Kays, “Convective Heat and Mass Transfer,” Mc- Graw-Hill, Boston, 1966.

[22] W. M. Kays and H. G. Perkins, “Handbook of Heat Transfer,” McGraw-Hill, Boston, 1972.

[23] M. N. Ozisik, “Basic Heat Transfer,” McGraw-Hill, Boston, 1977.

[24] F. M. White, “Heat Transfer,” Addison-Wesley, Boston, 1984.