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Title: Laminar natural convection in vertical tubes with one end open to a large reservoir: A numerical solution

Journal Article · · Numerical Heat Transfer. Part A, Applications; (United States)
;  [1]
  1. Oregon State Univ., Corvallis, OR (United States). Dept. of Mechanical Engineering

A two-dimensional finite difference computer program in cylindrical coordinates has been developed to solve the case of laminar natural convection in a vertical tube open to large reservoir. Such a device, the open thermosyphon, is used in a number of applications, including the cooling of gas turbines, geothermal energy extraction, and thermosyphon solar water heaters. The objective of this work were to study the nature of fluid flow and the heat transfer rate along the tube wall. A semi-implicit, time marching, finite difference solution procedure was used, satisfying continuity, momentum, and energy equations for incompressible flow. Results show three well-defined flow regimes appearing as functions of the tube length-to-radius (aspect) ratio. Fluid motion in the tube and heat transfer rates became oscillatory at long time intervals. Plots of streamlines and isotherms at selected times for different aspect ratio tubes are also presented to show the transition behavior of fluid motion.

OSTI ID:
6954089
Journal Information:
Numerical Heat Transfer. Part A, Applications; (United States), Vol. 26:2; ISSN 1040-7782
Country of Publication:
United States
Language:
English