Unsteady Laminar Flow in a Duct With Unsteady Heat Addition

1961 ◽  
Vol 83 (4) ◽  
pp. 432-440 ◽  
Author(s):  
Morris Perlmutter ◽  
Robert Siegel
Keyword(s):  
Heat Transfer ◽  
Laminar Flow ◽  
Nuclear Reactor ◽  
Transient Processes ◽  
Channel Cross Section ◽  
Fluid Temperature ◽  
Parallel Plates ◽  
Reactor Shutdown ◽  
Thermal Entrance ◽  
Insight Into

An analysis is made of transient heat transfer with transient laminar flow between heated (or cooled) parallel plates. The transient processes are caused by simultaneously changing the fluid pumping pressure and either the wall temperature or the wall heat flux. The solution is obtained for both the thermal entrance and fully developed heat-transfer regions. The slug-flow simplification is made; that is, the velocity at any instant of time is taken as uniform throughout the channel. The fluid temperature distribution, however, depends on both the axial co-ordinate and the position within the channel cross section. A few numerical examples are carried out which give some insight into various transient processes such as those occurring during a nuclear-reactor shutdown.

Laminar Heat Transfer in a Channel With Unsteady Flow and Wall Heating Varying With Position and Time

1963 ◽  
Vol 85 (4) ◽  
pp. 358-365 ◽  
Author(s):  
R. Siegel ◽  
M. Perlmutter
Keyword(s):  
Heat Transfer ◽  
Cross Section ◽  
Heat Production ◽  
Fluid Velocity ◽  
Isothermal Condition ◽  
Convection Heat Transfer ◽  
Channel Cross Section ◽  
Fluid Temperature ◽  
Parallel Plates ◽  
General Relations

An analysis is made of incompressible laminar forced convection heat transfer between two parallel plates that have a specified heat production to be dissipated at their surfaces. The heat production can vary in an arbitrary manner with time and position along the channel, starting from an initially isothermal condition. The fluid velocity is assumed constant over the channel cross section, but can vary with time. The variation of fluid temperature over the channel cross section is accounted for. General relations are presented in closed form and their application is illustrated by carrying out some typical examples. The results are compared with previous analyses that have assumed constant temperatures over the channel cross section and a constant heat-transfer coefficient.

scholarly journals Basic analysis on heat transfer phenomena in natural circulation for liquid sodium

2021 ◽  
Vol 2072 (1) ◽  
pp. 012012
Author(s):  
R Wulandari ◽  
S Permana ◽  
Suprijadi
Keyword(s):  
Heat Transfer ◽  
Nuclear Reactor ◽  
Cooling System ◽  
Natural Circulation ◽  
Liquid Sodium ◽  
Navier Stokes ◽  
Circulation System ◽  
Fluid Temperature ◽  
Navier Stokes Equation ◽  
Basic Equations

Abstract Natural convention, the heat transfer on fluid due to density differences that can be caused by differences in fluid temperature. One example application of natural convection is cooling system, such as nuclear reactor cooling system. The purpose of this study is to analysis the basic characteristic heat transfer of sodium liquid in the natural circulation system for steady state analysis and transient characteristic with Finite Element Method. The selected module is the Non-Isothermal FLow (NITF) module. This module is a combination of three basic equations, namely the continuity equation, the Navier-Stokes equation, and the dynamic equation of heat transfer in fluid. The simulation model measures 1.5 x 2 (m) with sodium liquid (Na) as a fluid.

Optimization of Micro Channel Morphology

2006 ◽  
Author(s):  
Aleksander Vadnjal ◽  
Ivan Catton
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Porous Media ◽  
Cross Section ◽  
Channel Morphology ◽  
Channel Cross Section ◽  
Micro Channel ◽  
Parallel Plates ◽  
Conservation Of Energy ◽  
Micro Channels

An increasing demand for a higher heat flux removal capability within a smaller volume for high power electronics led us to focus on micro channels in contrast to the classical heat fin design. A micro channel can have various shapes to enhance heat transfer, but the shape that will lead to a higher heat flux removal with a moderate pumping power needs to be determined. The standard micro-channel terminology is usually used for channels with a simple cross section, e.g. square, round, triangle, etc., but here the micro channel cross section is going to be expanded to describe more complicated and interconnected micro scale channel cross sections. The micro channel geometries explored are pin fins (in-line and staggered), parallel plates and sintered porous micro channels (see Fig.1). The problem solved here is a conjugate problem involving two heat transfer mechanisms; 1) porous media effective conductivity and 2) internal convective heat transfer coefficient. Volume averaging theory (VAT) is used to rigorously cast the point wise conservation of energy, momentum and mass equations into a form that represents the thermal and hydraulic properties of the micro channel (porous media) morphology. Using the resulting VAT based field equations, optimization of a micro channel heated from one side is used to determine the optimum micro channel morphology. A small square of 1 cm 2 is chosen as an example and the thermal resistance, 0C/W, and pressure drop are shown as a function of Reynolds number.

Sign in / Sign up

Export Citation Format

Share Document