Conduction of heat through slabs and walls
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Conduction of heat through slabs and walls a differential-difference approach for design, energy analysis and building automation applications by Jouko Pakanen

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Published by Technical Research Centre of Finland in Espoo, [Finland] .
Written in English

Subjects:

  • Heat -- Conduction.,
  • Differential-difference equations.,
  • Boundary value problems.,
  • Heat equation.

Book details:

Edition Notes

StatementJouko Pakanen.
SeriesVTT publications -- 162., VTT julkaisuja -- 162.
ContributionsValtion teknillinen tutkimuskeskus.
The Physical Object
Pagination72, [12] p. :
Number of Pages72
ID Numbers
Open LibraryOL15425649M
ISBN 109513844005

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@article{osti_, title = {Conduction of heat through one- and multilayer slabs: A differential-difference approach}, author = {Pakanen, J}, abstractNote = {A novel method for calculating transient heat flow through slabs and walls is presented. The method is based on differential-difference equation of heat conduction with continuous space variable and discretized time variable. BureauofStandardsJournalofResearch [Voi.e allanditssurroundingshadreflectingsurfacesof clean,brightmetal,theinterchangeofheatbyradiationwouldbe. unchanged with time during steady heat transfer through a medium at any location, although both quantities may vary from one location to another (Fig. 2–4). For example, heat transfer through the walls of a house is steady when the conditions inside the house and the . Consider steady heat conduction through the walls of a house during a winter day. We know that heat is continuously lost to the outdoors through the wall. We intuitively feel that heat transfer through the wall is in the normal direc-tion to the wall surface, and no significant heat transfer takes place in the wall in other directions (Fig. 3–1).

  Firstly, using the equation above for heat conduction through compound slab as a reference and note that the surface of the insulating material has the same temperature as the air. Heat power radiated from the steam pipe is the same in the inner slab and outer slab at steady state. The heat transmission through a building wall or similar construction can be expressed as: H t = U A dt (1). where. H t = heat flow (Btu/hr, W, J/s). U = overall heat transfer coefficient, "U-value" (Btu/hr ft 2 o F, W/m 2 K). A = wall area (ft 2, m 2). dt = temperature difference (o F, K). The overall heat transfer coefficient - the U-value - describes how well a building element conducts.   Details. The heat flux from the wall with generation is uniform and directed toward the right. where is in, is the thickness of the wall with generation (m) and is the volumetric heat generation rate ().. A thermal circuit is considered from the right side of the wall with generation to the air with forced convection. If is the wall with generation, then the heat flux can be written as. is a platform for academics to share research papers.

1. A composite wall consists of three layers of thicknesses mm, mm andmm with thermal conductivities , and is W/m K respectively. The inside surface is exposed to gases at °C with convection heat transfer coefficient as 30W/m 2 K. The temperature of air on the other side of the wall is 30°C with convective heat transfer coefficient 10 Wm 2 K. ME – Heat Transfer 1 Steady Heat Transfer with Conduction and Convection for Heat Generation in a Slab 0 1 2 heat through wall equals the heat leaving the wall by convection and radiation Q&1 =Q&2 +Q&3 Figure from Çengel, Heat and. Before getting into further details, a review of some of the physics of heat transfer is in order. As you recall from undergraduate heat transfer, there are three basic modes of transferring heat: conduction, radiation, and convection. Conduction is the transfer of heat through a medium by virtue of a temperature gradient in the medium. Conduction through a wall. Consider the convective heat from a single slab (ignoring the heat transfer through the wall). where: T 1: Temperature at the end of slab 1 (K).