Heat transfer circular cylinder

Wiebelt J.A., Ruo S.Y. (1963) Radiant-interchange configuration factors for finite right circular cylinder to rectangular plane. International Journal of Heat Mass Transfer 6, 143-146. 

Consider heat transfer from a circular cylinder whose axis is normal to a forced flow and which is rotating at an angular velocity, o>. If the surface of the cylinder is maintained at a uniform temperature, find the dimensionless parameters on which the Nusselt number depends. 

Air flows at a velocity of 2 m/s normal to the axis of a circular cylinder with a diameter of 2.5 cm. The surface of the cylinder is kept at a uniform surface temperature of 50°C and the temperature in the air stream ahead of the cylinder is 10°C. Assuming that the flow is two-dimensional. And the heat transfer rate in the vicinity of the stagnation point. 

Oosthuizen. PH.. Mixed Convective Heat Transfer From Inclined Circular Cylinders , Experimental Heat Transfer, Fluid Mechanics, and Thermodynamics 1989, Proc. First World Conference on Experimental Heat Transfer, Fluid Mechanics and Thermodynamics, Dubrovnik, Yugoslavia, Sept. 1988, pp. 200-207. 

Morgan, V.T., The Overall Convective Heat Transfer from Smooth Circular Cylinders , Adv. Heat Transfer, Vol. 11, p. 199, 1975. 

Using the procedure outlined in this chapter for using the boundars laser equations to find the-forced convective heat transfer rate from a circular cylinder buried in a saturated porous medium, investigate the heat transfer rate from cylinders with an elliptical cross-section with their major axes aligned with the forced flow. The surface velocity distribution should be obtained from a suitable book on fluid mechanics. 

Churchill, S. W., and M. Bernstein A Correlating Equation for Forced Convection from Gases and Liquids to a Circular Cylinder in Crossflow, J. Heat Transfer, vol. 99, pp. 300-306, 1977. 

An increase in Be indicates a competition between the irreversibilities caused by heat transfer and friction. At high Reynolds numbers, the distribution of Be is relatively more uniform than at lower Re. For a circular Couette device, the Reynolds number (Re = wr2lv) at the transition from laminar to turbulent flow is strongly dependent on the ratio of the gap to the radius of the outer cylinder, 1 — n. The critical Re reaches a value 50,000 at 1 n 0.05. We may control the distribution of the irreversibility by manipulating various operational conditions such as the gap of the Couette device, the Brinkman number, and the boundary conditions. 

No. 69004 (1969) Convective heat transfer during forced cross flow of fluids over a circular cylinder, including convection effects. 

T. Cebeci. Laminar Free Convection Heat Transfer from the Outer Surface of a Vertical Slender Circular Cylinder. Proceedings of Fifth International Heal Transfer Conference paper HCl.-i, 1974 pp. 15-19. 

J. Schmid, Longitudinal laminar flow in an array of circular cylinders, nt. J. Heat Mass Transfer 9 925 (1966). 

J. H. Kim, Heat transfer in longitudinal laminar flow along circular cylinders in a square array. Fluid Flow and Heat Transfer over Rod or Tube Bundles (S.C. Yao and P.A. Pfund, eds.), Winter annual meeting of the American Society of Mechanical Engineers, December 2-7, New York, 1979, p. 155. 

Fig. 3.24 Local heat transfer coefficients in flow across a circular cylinder, according to Giedt [3.14]...

Sparrow, E.M. Abraham, J.P. Tong, J.C.K. Archival correlations for average heat transfer coefficients for non-circular and circular cylinders and for spheres in cross flow. Int. J. Heat Mass Transfer 47 (2004) 5285-5296... 

Similar results are given by Schlicting (12) for the heat transfer to a circular cylinder in cross-flow at varying degrees of turbulence. At the highest turbulence value. 

To illustrate this fact, we may consider the 2D heat transfer problem of uniform flow past a heated circular cylinder with uniform surface temperature. In this case, if we look for a solution in the asymptotic form (9-15) for low Peclet numbers, the nondimensional governing equation and boundary conditions for do are again (9-16) and (9-17), but this time are expressed in cylindrical coordinates, namely,... 

Problem 9-5. Heat Transfer From a Freely Rotating Circular Cylinder in Shear Flow... 

Problem 9-13. Heat Transfer From a Circular Cylinder in an Inviscid Fluid. Determine the dimensionless rate of heat transfer from a circular cylinder of radius a immersed in a uniform flow of an inviscid fluid. Because there is no vorticity in the free stream, the velocity field can be written in terms of a potential, u = V, with V2 = 0. The boundary conditions are u U as r -> oo, and u n = 0 at r = a. The cylinder is maintained at temperature 7), while the fluid far from the cylinder is at 7o. 

The solution of the corresponding mass exchange problem for a circular cylinder and an arbitrary shear flow was obtained in [353] in the diffusion boundary layer approximation. It was shown that an increase in the absolute value of the angular velocity Cl of the shear flow results in a small decrease in the intensity of mass and heat transfer between the cylinder and the ambient... 

In the mass exchange problem for a circular cylinder freely suspended in linear shear flow, no diffusion boundary layer is formed as Pe - oo near the surface of the cylinder. The concentration distribution is sought in the form of a regular asymptotic expansion (4.8.12) in negative powers of the Peclet number. The mean Sherwood number remains finite as Pe - oo. This is due to the fact that mass and heat transfer to the cylinder is blocked by the region of closed circulation. As a result, mass and heat transfer to the surface is mainly determined by molecular diffusion in the direction orthogonal to the streamlines. In this case, the concentration is constant on each streamline (but is different on different streamlines). 

Film condensation on a horizontal tube. For a curvilinear surface, in particular, for a horizontal circular cylinder along which a condensate film flows, the angle 6 is a nonconstant variable. By taking into account the fact that 6(6) d, where d is the diameter of a circular cylinder, and proceeding by analogy with (5.7.7), one can readily obtain the following formula for the heat transfer coefficient averaged over the external surface of the tube provided that the flow in the condensate film is laminar [200] ... 

This equation is encountered in heat transfer problems with cylindrical symmetry (e.g., heat exchange between a circular cylinder and the ambient medium, with r being the dimensionless radial coordinate). 

Kassoy, D. R., Heat transfer from circular cylinders at low Reynolds number, Phys. Fluids, Vol. 10, No. 5, pp. 938-946, 1967. 

Robertson, C. R. and Acrivos, A., Low Reynolds number shearflow past a rotating circular cylinder. Part 2. Heat transfer, J. Fluid Mech., Vol. 40, No. 4, pp. 705-718, 1970. 

Figure 6.9 Average heat transfer coefficient versus Reynolds number for a circular cylinder in cross flow with air (from McAdams [25]).

S. W. Churchill and M. Berstein, A correlating equation for forced convection from gases and liquids to a circular cylinder in crossflow, J. Heat Transfer, 99,300-306,1977. 

V. T. Morgan, The overall convective heat transfer from smooth circular cylinders, Advances in Heat Transfer (T.F. Irvine and J.P. Hartnett, eds.), 11. Academic Press, New York, 1975, pp. 199-264. 

Rgure 6-2 Areas of right circular cylinders and a sphere of equal volume. The area excludes the circular areas of the cylinder ends, where little heat transfer occurs in a reactor... 

The basic solutions for the infinite plates and infinitely long cylinders can be used to obtain solutions for multidimensional systems such as long rectangular plates, cuboids, and finite circular cylinders with end cooling. The texts on conduction heat transfer [4,11, 23, 29, 38, 49,56, 87] should be consulted for the proofs of the method and other examples. 

The thin-layer approximation fails because natural convective boundary layers are not thin. From the interferometric fringes in Fig. 4.2ft (which are essentially isotherms), the thermal boundary layer around a circular cylinder is seen to be nearly 30 percent of the cylinder diameter. For such thick boundary layers, curvature effects are important. Despite this failure, thin-layer solutions provide an important foundation for the development of correlation equations, as explained in the section on heat transfer correlation method. 

For example, to determine Nu, for the case where the body is a very long horizontal isothermal circular cylinder of diameter D, the relevant heat transfer would then be that by heat conduction across a cylindrical annulus of inner diameter D, inner temperature T , outer diameter D + 2A, and outer temperature 7U (assumed constant). Calculating this heat transfer by standard methods, substituting Eq. 4.16, and converting to a Nusselt number yields... 

---