The Effect of Coatings on the Steady-State and Short Time Constriction Resistance for an Arbitrary Axisymmetric Flux

1985 ◽  
Vol 107 (1) ◽  
pp. 33-38 ◽  
Author(s):  
J. R. Dryden ◽  
M. M. Yovanovich ◽  
A. S. Deakin
Keyword(s):  
Thermal Properties ◽  
Steady State ◽  
Heat Flow ◽  
Contact Spot ◽  
One Dimensional ◽  
Constriction Resistance ◽  
Transient Heat Flow ◽  
Flow Through ◽  
Short Time ◽  
Short Times

The effect of a coating upon the short-time and steady-state constriction resistance is analyzed for an arbitrary axisymmetric contact spot flux. At very short times the expression obtained for R is identical to the expression for one-dimensional transient heat flow through a two-layer wall. At steady-state, the results of the analysis predict that the effect of the coating are mainly dependent on the relative thermal properties of the coating and substrate. The limiting cases, where the coating thickness approaches either zero or infinity, are discussed.

Gravity-induced wrinkle lines in vertical membranes

1981 ◽  
Vol 375 (1762) ◽  
pp. 307-325 ◽  
Keyword(s):  
Heat Flow ◽  
Diffusion Equation ◽  
Vertical Plane ◽  
One Dimensional ◽  
Dimensional Diffusion ◽  
Prime Objective ◽  
Flow Through ◽  
Flexible Membranes ◽  
The One

A theory is presented for the behaviour under self-weight of inextensible but perfectly flexible membranes supported in a vertical plane. Slack in the membrane manifests itself in the formation of (curved) wrinkle lines whose determination is the prime objective. The equilibrium and strain conditions are derived and solutions are given for several simple cases. It is shown that the wrinkle lines satisfy the one-dimensional diffusion equation and hence there are analogies, for example, with heat flow through a slab.

Thin Disk On A Convectively Cooled Plate—Application To Heat Flux Measurement Errors

1979 ◽  
Vol 101 (2) ◽  
pp. 346-352 ◽  
Author(s):  
D. A. Wesley
Keyword(s):  
Heat Flux ◽  
Heat Flow ◽  
Measurement Errors ◽  
Heat Conduction Problem ◽  
Flux Measurement ◽  
Thin Disk ◽  
Plate Temperature ◽  
One Dimensional ◽  
Solid Plate ◽  
Flow Through

An analysis is made of the steady-state thermal processes associated with a thin disk affixed to a convectively cooled solid plate. The disk represents a thermopile heat flux gauge. In the first part of the paper, the heat conduction problem of the plate is solved for the simplified condition where the heat flow through the disk is axially one-dimensional. It was found that the local divergence of the heat flux field within the plate owing to the presence of the disk may result in a gauge reading that underestimates the heat transfer rate. Also, a sizeable local plate temperature augmentation can occur. Furthermore, the analysis yields dimensional estimates of the region where the temperature and heat flux fields within the plate are significantly altered by the presence of the disk. An adjunct to the foregoing analysis develops a one-dimensional conduction factor which is useful in determining when the heat flow through the disk can be considered to be axially one-dimensional.

Performance Indicators for Steady-State Heat Transfer Through Fin Assemblies

1996 ◽  
Vol 118 (2) ◽  
pp. 310-316 ◽  
Author(s):  
A. S. Wood ◽  
G. E. Tupholme ◽  
M. I. H. Bhatti ◽  
P. J. Heggs
Keyword(s):  
Heat Transfer ◽  
Steady State ◽  
Heat Flow ◽  
Performance Indicators ◽  
Physical Parameters ◽  
State Heat ◽  
Extended Surface ◽  
Flow Through ◽  
Steady State Heat ◽  
Steady State Heat Transfer

A comparative study is presented of several models describing steady-state heat flow through an assembly consisting of a primary surface (wall) and attached extended surface (fin). Attention is focused on the validity of four performance indicators. The work shows that the augmentation factor is the only indicator capable of correctly predicting the behavioral trends of the rate of heat flow through the assembly as the influencing physical parameters are varied.

scholarly journals Steady-state heat flow through hollow clay bricks

2020 ◽  
Vol 834 ◽  
pp. 012021
Author(s):  
H Ghailane ◽  
M A Ahamat ◽  
M Md Padzi ◽  
S Beddu
Keyword(s):  
Steady State ◽  
Heat Flow ◽  
Clay Bricks ◽  
State Heat ◽  
Flow Through ◽  
Steady State Heat

scholarly journals Thermal Bridge Modeling and a Dynamic Analysis Method Using the Analogy of a Steady-State Thermal Bridge Analysis and System Identification Process for Building Energy Simulation: Methodology and Validation

Energies ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 4422
Author(s):  
Heegang Kim ◽  
Myoungsouk Yeo
Keyword(s):  
Steady State ◽  
Heat Flow ◽  
Dynamic Analysis ◽  
Building Energy ◽  
Energy Simulation ◽  
Building Energy Simulation ◽  
Analysis Method ◽  
Identification Process ◽  
Thermal Bridge ◽  
Flow Through

It is challenging to apply heat flow through a thermal bridge, which requires the analysis of 2D or 3D heat transfer to building energy simulation (BES). Research on the dynamic analysis of thermal bridges has been underway for many years, but their utilization remains low in BESs. This paper proposes a thermal bridge modeling and a dynamic analysis method that can be easily applied to BESs. The main idea begins with an analogy of the steady-state analysis of thermal bridges. As with steady-state analysis, the proposed method first divides the thermal bridge into a clear wall, where the heat flow is uniform, and the sections that are not the clear wall (the thermal bridge part). For the clear wall part, the method used in existing BESs is applied and analyzed. The thermal bridge part (TB part) is modeled with the linear time-invariant system (LTI system) and the system identification process is performed to find the transfer function. Then, the heat flow is obtained via a linear combination of the two parts. This method is validated by comparing the step, sinusoidal and annual outdoor temperature response of the finite differential method (FDM) simulation. When the thermal bridge was modeled as a third-order model, the root mean square error (RMSE) of annual heat flow with the FDM solution of heat flow through the entire wall was about 0.1 W.

Transient Heat Flow through Building Elements

2016 ◽  
pp. 211-239
Author(s):  
T. Agami Reddy ◽  
Jan F. Kreider ◽  
Peter S. Curtiss ◽  
Ari Rabl
Keyword(s):  
Heat Flow ◽  
Transient Heat Flow ◽  
Flow Through ◽  
Building Elements
Sign in / Sign up

Export Citation Format

Share Document