A Numerical Study of the Effect of Aspect Ratio on Heat Transfer in an Annular Flow Through a 270-Degree Curved Pipe.

Document Type : Research Paper

Authors

Department of Mechanical Engineering, Tarbiat Modares University, Tehran, Iran

Abstract

In the present paper, a three dimensional annular developing incompressible laminar flow through 270- degree curved pipe is numerically simulated. The dimensionless governing equations of continuity, momentums and energy are driven in toroidal coordinates. The governing equations are discretized by projection algorithm using forward difference in time and central difference in space. A three-dimensional computer code together with a grid generation program are developed in toroidal coordinates by which the present results were obtained. There is a non-uniform heat source q˝=BeAθ in the solid core and the outer wall is assumed to be adiabatic. Considering the effect of Reynolds number on thermo-hydraulic properties such as formation of secondary flow and axial velocity, it is possible to increase heat transfer using a non-uniform heat flux instead of the uniform one. The numerical results indicated that the average Nusselt number is increased by non- uniform heat flux compared with the uniform one assuming that both have the same average flux values. Also, the results indicate heat transfer increases as the aspect ratio is reduced.

Keywords

References

[1] Dean WR. XVI. Note on the motion of fluid in a curved pipe. The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science. 1927 Jul 1;4(20):208-23.
[2] Robertson AM, Muller SJ. Flow of Oldroyd-B fluids in curved pipes of circular and annular cross-section. International Journal of Non-Linear Mechanics. 1996 Jan 1;31(1):1-20.
[3] Kapur JN, Tyagi VP, Srivastava RC. Streamline flow through a curved annulus. Applied Scientific Research, Section A. 1965 Jan 1;14(1):253-67.
[4] Hoon KC, Park SO. Laminar entrance flow in curved annular ducts. International Journal of Heat and Fluid Flow. 1992 Mar 1;13(1):41-9.
[5] Petrakis MA, Karahalios GT. Steady flow in a curved pipe with a coaxial core. International Journal for Numerical Methods in Fluids. 1996 Jun 30;22(12):1231-7.
[6] Petrakis MA, Karahalios GT, Kaplanis S. Steady flow in a curved pipe with circular cross-section. comparison of numerical and experimental results. The Open Fuels & Energy Science Journal. 2009 May 26;2(1):20-6.
[7] Kara-halios GT. Mixed convection flow in a heated curved pipe with core. Physics of Fluids A: Fluid Dynamics. 1990 Dec;2(12):2164-75.
[8] Park SM. Numerical simulation of core-annular flow in curved pipe [master's degree]. Delft: Delft University of Technology; 2014.
[9] Guan X, Martonen TB. Simulations of flow in curved tubes. Aerosol Science and Technology. 1997 Jan 1;26(6):485-504.
[10] Tarbell JM, Samuels MR. Momentum and heat transfer in helical coils. The Chemical Engineering Journal. 1973 Jan 1;5(2):117-27.
[11] Pantokratoras A. Steady laminar flow in a 90 bend. Advances in Mechanical Engineering. 2016 Sep;8(9):1-9.
[12] Riley N. Unsteady fully-developed flow in a curved pipe. Journal of Engineering Mathematics. 1998 Jul 1;34(1-2):131-41.
[13] Hasan LD. Transient Three-dimensional Numerical Analysis of Forced Convection Flow and Heat Transfer in a Curved Pipe. IOSE Journal of Mechanical and Civil Engineering. 2013;9(5):47-57.
[14] Dutta P, Nandi N. Effect of Reynolds number and curvature ratio on single phase turbulent flow in pipe bends. Mechanics and Mechanical Engineering. 2015;19(1):5-16.
[15] Austin LR, Seader JD. Entry region for steady viscous flow in coiled circular pipes. AIChE Journal. 1974 Jul;20(4):820-2.
[16] Siggers JH, Waters SL. Steady flows in pipes with finite curvature. Physics of Fluids. 2005 Jul 6;17(7):077102.
[17] Chorin AJ. Numerical solution of the Navier-Stokes equations. Mathematics of Computation. 1968;22(104):745-62.
[18] White FM, Corfield I. Viscous fluid flow. New York: McGraw-Hill; 2006.
Journal of Chemical and Petroleum Engineering
Volume 53, Issue 1
June 2019
Pages 101-110

Files

Share

How to cite

Statistics