Essays on Thermal Conductivity

Abstract:

The principal intention of this study was to come up with the most conducive internal environment in a building. At any given moment, the internal temperature of a building is a function of the amount of heat produced by sources therein and the net heat transfer into or out of the building. The four heat transfer modes are convection, radiation, conduction, and phase- change. In executing this project, the researchers sought the relevant literature to establish the thermal properties of various materials. The properties are critical in determining the amount of heat inflow and exit from the building. The ...

Summary

While all the components of a brake system are important, it is imperative to acknowledge that some components play significant roles in the system as compared to others. One such component is the brake pad. In most cases, the brake pad is referred to as the friction material. It is responsible for generating the friction which opposed the movement of the wheel thus causing a stop to the movement of the automotive. This report is aimed at selecting a section or component of the brake system and presents its modification. As a consequence, the report highlights and discusses the ...

It is evident, and all would agree, that the house should be strong, durable, built quickly and at a relatively inexpensive cost. In most cases, disputes begin on the choice of building materials. Which would be stronger, thermal insulated, warmer – wood, brick, concrete, or polymer-based materials? Which of them are considered environmentally friendly and which are not? Until recently, metal, steel in particular was not part of the discussion on the material for the construction of the frame of an individual house. However, the development of energy-efficient technology, the translucent structures based on steel beams are built today even ...

Material extraction

The mining and extraction of copper has several impacts on the environment. The extraction of copper is done in several steps and process using different technologies and mechanisms. The copper element is extracted from its ore through heating the ore using carbon. This process releases carbon dioxide gas into the atmosphere. It is a well known fact that carbon dioxide gas is a greenhouse gas which result into global warming. The result of the extraction is copper full of impurities. The impure copper is then placed under further treatment to eliminate the presence of the impurities. In most cases, ...

Thermal conductivity is defined as a material’s property to conduct heat. Heat transfer across materials occurs in materials that have lower thermal conductivity and transfers faster in materials with high conductivity. It is important to determine the thermal conductivity of materials since different materials are used for different applications. For instance, materials with high conductivity are more efficient when they are used as heat sinks since they can conduct heat away faster. Those with lower thermal conductivity are often used as insulators (Callister 78). The classical transfer of energy happens through conduction, radiation, convection or combination of all ...

Purpose

This experiment was intended for determining the thermal conductivity of aluminum metal. Apparatus The following materials were used in the experiment: Variac Timer Digital thermometer 2 digital multimeters

Beakers

Tin can Double throw switchers Mercury thermometer Heating plate Wire Ice cold water Introduction Heat flows from a hot region to a cooler region. However, the rate of heat flow varies from one medium to another. Heat travels through different media such as air, solid, and liquid. The mechanisms of heat transfer differ from one medium to another. For example, heat travels through a solid object by conduction while it travels ...

Introduction

Selection of materials is an important part of engineering design. Material selection is aimed at increasing the performance as well as the life of the engineering component and hence, very important for success of engineering component. The nature of loading, expected life, working environment amongst other factors determines the material to be selected for a particular application.

Therefore, engineers and designers must determine the properties of materials before they incorporate them in their design. Mechanical properties of materials such as ultimate tensile strength, Modulus of Elasticity, proof stress, specific strength, toughness and density amongst others are some of the important ...

Objectives

The aim of this experiment is to study the effective thermal conductivity of a heat pipe. This is achieved by measuring the difference in temperature across the heat pipe and another conductor made of the same material and size. The temperature measurement for both the pipe and conductor is done under identical thermal conditions.

Apparatus

- Copper-water heat pipe – The specimen whose thermal conductivity is to be found. It is represented in Figure 1. - Solid Copper Wire – The reference material of same size. - Thermocouple (quantity – 3) – Temperature measuring instrument (analogue). - Multi-channel digital thermometer – Temperature measuring ...

Methods of Heat Transfer

Conduction The first method through which heat is transferred from one object to another is conduction. Conduction occurs in liquids and solids through transfer of kinetic energy present in one particle to the immediate particle(s) in its surrounding. By considering the bonds existing between atoms and molecules in solids as elastic links, the vibration of one particle due to increase energy level caused by heat, the next in its line vibrate too. This process is replicated in adjacent particles thereby allowing transfer of thermal energy from a body with a higher temperature as compared to the one with low ...

Introduction

Tensile testing is usually conducted to select a material for its application, quality control, and to forecast how the material is likely to react on deployment of different types of forces. The properties evaluated through the tensile test include the ultimate tensile strength, the maximum elongation, X-area reduction and so forth. These evaluations facilitate determination of such properties as Young’s Modulus, yield strength, Poisson’s ratio, and the characteristics of strain hardening [1. 2]. Tensile testing on glass fibre is, thus, performed to determine the quality of the material it contains, and to ascertain its suitability for various applications.

History of Fibre Glass

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Currently the EN 771-1 has been revised in order to adapt the new element of the Construction Products regulation. This exercise entailed stipulations of the usage of the product and modification to the new CE design and the affirmation of the performance. The new law requires the manufacturers of the construction materials to apply the CE markings. Art. 11 of the CPR emphasis that the manufacturer has to fulfil the obligation of drawing up the declaration performance and to affix the CE marking.

Introduction

The product category rules are important in preparation of the EPDs for manufactured concrete and the ...

The following were the main objectives of this experiment:

Methodology The following apparatus were used in this experiment: - Copper-water heat pipe - Hot plate - Thermocouple (3) - Ring stand with clamps (2) - Solid copper wire - Glass beaker (2) - Multichannel digital thermometer - Vernier caliper Figure 1 below shows the illustration of copper-water heat pipe: According to Fig. 1, The three main components of a heat pipe are the working fluid, vacuum tight containment vessel and the capillary/wick vessel. The operation of these three elements ensures the efficient and even heat transfer between heat ...

The main objective of this experiment was to measure the temperature difference across a heat pipe and a solid conductor of the same material and size and under the same thermal conditions. Secondly, to use the data obtained herein to determine an effective thermal conductivity of the heat pipe.

Methodology

Apparatus - Copper-water heat pipe - Hot plate - Thermocouple (3) - Ring stand with clamps (2) - Solid copper wire - Glass beaker (2) - Multichannel digital thermometer - Vernier caliper

The copper water heat pipe apparatus is illutrated as shown below:

Figure 1: A Basic heat pipe

Description of the apparatus

heat pipes are passive heat transfer ...

Q1:

There are four classes/or types of materials that are considered as listed below

- Ceramics and Glasses - Composite materials - Polymers - Metal alloys First generalized properties of the materials will be discussed, and then based on these properties one material will be selected for a specific application. - Ceramics and Glasses Ceramics and Glasses are inorganic, non-metallic materials consisting of metallic and non-metallic elements bonded with ionic and covalent bonds. These are high strength bonding gives special characteristics to these materials.

The typical properties of these materials are as:

- Low to moderate density compared to metals, - High modulus of elasticity, - Provide good strength at elevated level of ...

Introduction

The destructive testing of the materials is often used to find out the material properties. The mechanical property is based on the parameters obtained from the material testing. The testing involves tensile testing, hardness testing, creep testing, and impact testing. The non destructive testing involves interaction of energy with the materials. It is necessary to decide the behaviour of the material by knowing the property of the materials. The structure of the material at the atomic level will guess the characteristic of the material at the atomic level. The materials fall into the category of metallic, ceramic, and polymeric. ...

The Research .3

Cooking Pans: The Basic Requirements ...3 Composite Materials ..4

Nonstick Pans 4

Prioritizing High Heat Capability ..4

Conclusions 5

Introduction This research paper discusses the respective properties and qualities of cooking pans made from copper, iron, stainless steel, aluminum and composite materials, including those with non-stick (usually Teflon) interior surface coatings, to find what is the safest and best material to use for cooking food on a high heat setting, and to assess any dangers inherent in the materials discussed.

The Research

Cooking Pans: The Basic Requirements. According to Chu (2005), the purpose of the cooking pan is to efficiently impart the heat energy from ...

[Heat Lost From a 6-Inch OD Steam Line] Analyze heat lost from a 6-inch OD steam line. The line carries high-pressure steam throughout the factory at 400 psi, 400oF. Specify type and thickness for insulating the steam line. Compare the cost of energy lost with and without pipe insulation. You can assume steam is generated 8000 hours/year. Compare energy cost reductions based upon a gas fired boiler and a fuel oil fired boiler. Assume boiler energy input at 6.5(106) Btu/hr.

Given outer diameter OD = 6-inch, pressure = 400 psi, steam temperature = 400oF.

The following assumptions are made;

The steam pipe is made of mild steel The ...

Affiliated institution

Geothermal Binary Rankine Cycles Abstract This report is for a LOW-BIN (Efficient Low Temperature Geothermal project. The main objective is to study and recommend specific optimal Rankine cycles using water as the primary source of heat. The water is at a temperature of 1600C. This Rankine cycle is using R134 as working fluid for the geothermal power machine. This project is supposed to generate electricity from low temperature resources with profitable operation down up to around 600C. The main Rankine Cycle parameters and components are idealized. This is as found in the shell, the tube condenser and the heat ...

Abstract

This paper clearly presents and defines the numerical study on how hollow building block operates to suppress the convectional currents and reduce the amount of heat flux transferred across the petition of the building wall. The configuration and weight of these blocks have made them to fully be utilized in building the facades. The air filled cavities (hollow cells) together with the small cross-sectional area geometry provides an appropriate elevation for the building block. The hollow polythene bars inserted in this bricks also helps to reduce the heat by about 36% depending on the petition number (Mejad 2006). ...

This study revealed that Kevlar and Kevlar/wool fabric thermal properties. The effect of fabric physical properties on thermal comfort was analyzed. The tests conducted on moisture management techniques were: sweating guarded hot plate (SGHP), moisture management tester, and surface tester. A conclusion for the paper is given which recommends the use of Kevlar and Kevlar/wool in the textile industry. The report examines the different thermal properties of Kevlar A363 and Kevlar/wool in an effort to determine which fabric is best suited for different weather conditions. In addition, the tests carried out shows clearly the difference in thermal properties of ...

Abstract

Heat transfer through a cylindrical pin fin s studied. For the purposes of this study, thermal conductivity, heat transfer coefficient and the source terms and the sink terms are assumed to depend on the temperature. In the model being used for the study, the source and sink terms are given as arbitrary functions. We therefore employ techniques on symmetry to find the forms of the source and the sink terms which the extra lie point symmetries are admitted. The method of separating variables is used in the study to get the exact solutions when the equation for the equation is ...