Flow in heated curved pipes

Abstract

The fully developed laminar flow in a heated curved pipe under the influence of both centrifugal and buoyancy forces is studied analytically. The pipe is assumed to be heated so as to maintain a constant axial temperature gradient. Both horizontal and vertical pipes are considered. Solutions for these two cases are obtained by regular perturbations in the Dean number and the product of the Reynolds and Rayleigh numbers; the solutions are therefore limited to small values of these parameters. Predictions of the axial and secondary flow velocities, streamlines, shear stress, temperature distribution and heat transfer are given for a representative case.

An Experimental Investigation of Heat Transfer Coefficients for Spiral Plate Heat Exchanger

“…However, it did not affect the average Nusselt number. The effects of buoyancy forces on fully developed laminar flow with constant heat flux were studied analytically by Yao and Berger (Yao, L.-S., and S. A. Berger.,1978). Their studies were based on the Boussinesq approximation for the buoyancy forces and analyzed for both horizontally and vertically orientated curved pipes.…”

Flow in heated straight rotating pipe

“…Mori and Nakayama (1965) neglected the buoyancy force in their investigation and only the effect of centrifugal force was taken into consideration. Yao and Berger (1978) have treated the problem of flow of an incompressible viscous fluid in a heated curved pipe and the effect of both centrifugal force and buoyancy force has been considered in their analysis.…”

“…As the parameters are small, a method of successive approximations has been adopted to obtain the solution of the problem. As in the case of Yao and Berger (1978), secondary flow streamlines have been plotted in the plane of the cross section of the pipe. We have also plotted constant axial velocity contours and isotherms (constant temperature contours).…”

Numerical computation of buoyancy-induced recirculation in curved square duct laminar flow

“…A review of experimental, analytical and numerical studies up to 1975 is given in [1]. Examples of analytical and numerical· studies for the laminar floW regime are'given ;n, [2][3][4][5][6], ,and for the turbulent flow regime (using two-equation turbulence models) i,n [7][8][9]. While the laminar flow cases have yielded to numerical prediction and are currently limited mainly by cost considerations dictated by computational time and storage requirements, calculations of corresponding Motions driven by buoyant forces arise ducts with curvature the criterion is given turbulent flows are less accurate [9].…”

“…Depending on the relative orientation (with respect to gravity) of a curved duct geometry and the ratio of buoyant to inertial forces, reversed flow regions can be expected to appear in curved duct flows subjected to thermal effects. Examination of the literature published to date suggests that, although forced convection heat transfer has been investigated (see, for example, [5]), thermally induced buoyant motion in developing curved duct flow has peceived comparatively little attention [2,10,11]. 'This ;-s the case in spite of the relativeeasewHh which conditions are attained propitious to the occurrence of the phenomenon.…”