Estimation of thermal conductivity for materials of high thermal resistance

Dissertant

Muhsin, Zaynab Husayn

Thesis advisor

Hammadi, Muhammad M.
Jawad, Salah K.

University

University of Technology

Faculty

-

Department

Department of Production Engineering and Metallurgy

University Country

Iraq

Degree

Master

Degree Date

2013

English Abstract

Thermal conductivity is an important parameter, which helps us to design vital components in industry, where the right geometry (thickness) and material are needed.

Thermal conductivities of Copper , Aluminum Iron , Glass , Glass Wool and Wood have been determined using an electrical furnace designed to this perposes.

It consists of a heating chamber (with two heating elements within two layer insulation and one hole was made in the back wall of the furnace), specimen holder was set in an Alumina tube in order to obtain reasonable temperature uniformity along the sample.

This new technique is used in the present study to measure the thermal conductivity of some insulation materials at different elevated temperature.

The measurements were obtained for the temperature interval from 100 °C to 1100 °C .The thermal conductivities of Copper, Aluminum ,Steel ,Wood Glass and Glass Wool were measured using the system and the results obtained were compared statistically with other standards.When heated side is located in a furnace while the second side at the room temperature, the first conduction in this study starts with a solid Steel specimen of 80 mm length insulated from the outer surface only and the heat transfer is in the axial direction only .This condition of study gives the minimum different in temperature from the heated end of a temperature and the other end of a temperature because there is no any insulation type through the axial direction .The difference in temperature is about 173°C .The second condition is to use two pieces of solid specimen contacted with each other .They have same total length equivalent to the length of this solid Steel specimen 80 mm .The insulating element in this case can be assumed to be the resistance of the contact surface of both Steel specimens.

This condition gives 210 °C difference in temperature .But when the air gaps are used to be a thermal resistance of a distances (10, 20, 40) mm between the two pieces of Steel specimen which gives temperature differences of (255, 280 , 307) C which are the highest differences of the other insulating compared system with (Wood, Glass and Glass Wool) of the same thickness of Air gap.

Glass wool insulating material.

It gives the second best insulating material and the difference between all their results and Air gap results is about 5C.

ANSYS numerical software has been used in order to investigate the accuracy in data .A verification of numerical results with a previous computational work and with present experimental work, gives a good agreement also a good compatibility between the present experimental work and the experimental results given from literature.

Main Subjects

Engineering & Technology Sciences (Multidisciplinary)

Topics

• Thermal conductivity

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-413040