Convection round tubes

B20. Biancone, F., Companile, A., Galimi, G., and Goffi, M., Forced convection burn-out and hydrodynamic instability experiments for water at high pressure. 1. Presentation of data for round tubes with uniform and nonuniform power distribution, EUR 2490e (1965). 

D2. De Bortoli, R. A., Green, S. J., Le Tourneau, B. W., Troy, M., and Weiss, A., Forced convection heat transfer burnout studies for water in rectangular channels and round tubes at pressure above 500 psia, WAPD-188 (1958). 

H7. Hines, W. S., Forced convection and peak nucleate boiling heat transfer characteristics for hydrazine flowing turbulently in a round tube at pressures to 1000 psia, Rept. No. 2059, Rocketdyne, Canoga Park, California (1959). 

L4. Lee, D. H., and Obertelli, J. D., An experimental investigation of forced convection burnout in high pressure water. 1. Round tubes with uniform flux distribution, AEEW-R213 (1963). 

Katto Y (1978) A generalized correlation for critical heat flux for the forced convection boihng in vertical uniformly heated round tubes. Int J Heat Mass Transfer 21 1527-1542 Khrustalev D, Faghri A (1996) Fluid flow effect in evaporation from liquid-vapor meniscus. ASME J Heat Mass Transfer 118 725-747... 

Biancone, F., A. Campanile, G. Galimi, and M. Goffi, 1965, Forced Convection Burnout and Hydrodynamic Instability. Experiments for Water at High Pressure. I. Presentation of Data for Round Tubes with Uniform and Non-Uniform Power Distribution, Italian Rep. EUR-2490 e, European Atomic Energy Community, Brussels, Belgium. (5)... 

DeBortoli, R. A., S. J. Green, B. W. LeTourneau, M. Troy, and A. Weiss, 1958, Forced Convection Heat Transfer Burnout Studies for Water in Rectangular Channels and Round Tubes at Pressures above 500 psia, USAEC Rep. WAPD-188, Pittsburgh, PA. (5)... 

Lee, D. H., and J. D. Obertelli, 1963, An Experimental Investigation of Forced Convection Burnout in High Pressure Water, Part 2. Preliminary Results for Round Tubes with Non-Uniform Axial Heat Flux Distribution, UK Rep. AEEW-R-309, UK AEEW, Winfrith, England. (5)... 

Churchill, S. W., Turbulent Flow and Convection The Prediction of Turbulent Flow and Convection in a Round Tube, in Advances in Heat Transfer Academic Press, New York (J. P. Hartnett, T. F. Irvine, Y. I. Cho, and G. A. Greene, Eds.), (2001). 

Flow In Round Tubes In addition to the Nusselt (NuD = hD/k) and Prandtl (Pr = v/a) numbers introduced above, the key dimensionless parameter for forced convection in round tubes of diameter D is the Reynolds number Re = (.7 ) u where G is the mass velocity G = m/Ac and Ac is the cross-sectional area Ac = kD2I4. For internal flow in a tube or duct, the heat-transfer coefficient is defined as... 

Forced convective boiling in channels. Here, evaporation of a liquid occurs in flow in a channel (for instance, a round tube). The vapor generated and the remaining liquid form a two-phase flow within the tube, and there are strong interactions between this two-phase flow (which can occur in a number of different forms) and the boiling process. 

J. P. Wattelet, Predicting Boiling Heat Transfer in a Small Diameter Round Tube Using an Asymptotic Method, in Convective Flow Boiling, J. C. Chen ed., pp. 377-382, Taylor Francis, Washington, DC, 1996. 

Film Heat Transfer Coefficient Value Most of the experimental data for liquid metals in forced convection have been obtained for round tubes. Since a large fraction of heat transfer to liquid metals in forced convection is by molecular and electronic conduction, the velocity and temperature distribution of the fluid in the channel is expected to have a noticeable effect. Until data are obtained for the reference channel, however, the data for round tubes is used with the equivalent diameter of the channel replacing the diameter of the tube. Most of the round tube data fall below the L.yon-Martinelli theoretical prediction, and therefore 85% of the Lyon-Martinelli Nusselt Number is used as the best average value in the range of Peclet Number of interest (500-1000). The factor shown in Table X represents the expected accuracy of experimental data. 

Water sorption experiments were done with a Cahn RG balance on the PrintPack EX429-325 films. Constant water pressure was maintained using an MKS 2 5 2A pressure controller. The water source was contained in a round bottom flask and was flashed across a valve into the balance assembly. A low flow rate of water was maintained so that the pressure control valve could operate. Pressure was measured with an MKS 510A readout. The sample was suspended in a water-jacketed chamber at 20°C which was 4-5 °C cooler than the ambient so that the higher water vapor density in the sample tube minimized convection. 

The calculated convection surface usually will not correspond to an integral number of tube rows. In many cases, the computed surface is simply rounded up to an even number of tube rows, and the excess is considered a margin of safety. If a more exact rating is desired, it is necessary to assume a new overall efficiency and repeat the entire rating. The results can then be interpolated to the desired number of tubes. 

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