Thermal conductivity Definition and 185 Threads

Hello. As you can see, I'm new here. I have a little experience in physics and I've taken through Calc 2 in college. I'm trying to build a portable air conditioning unit. My current design consists of a tub of water with a 6" cube-shaped container of some kind submerged in it containing dry...

I 'trying to find the thermal conductivity of a silicon substrate doped with boron with known dopant concentration. Is there any way to calculate it or it has to be measured. Thanks in advance for any advice.

Strangely, this is for a Mat Sci Class. It is probably not as complicated as I am making it out to be, but the book has no suggestions on how to handle this problem. Homework Statement Calculate rate of heat loss through a fireclay refractory wall of wall with thickness .1m. Furnace...

Forgive me if I am posting in the wrong place. I have a problem dealing with thermal conductivity. I have an aluminum plate, approx. 12 in/ long, and 1.5 in. x 4 in on the end which is being applied with 200 W. What I'm interested in is how long it will take before the plate reaches a...

Homework Statement A mountain climber wears a goose down jacket 3.28 cm thick with total surface area 1.10 m2. The temperature at the surface of the clothing is -19.3°C and at the skin is 36.0°C. Determine the rate of heat flow by conduction through the jacket assuming it is dry and the...

Homework Statement A long rod, insulated to prevent heat loss along its sides, is in perfect thermal contact with boiling water (at atmospheric pressure) at one end and with an ice-water mixture at the other. The rod consists of a 1.00m section of copper (with one end in the boiling water)...

edit: not sure why this was moved to homework - it isn't. Hi :) I'm a bit embarrassed to ask this, but I hope someone can set me straight. As a second year university chem student I feel I should know this. In this question about thermal conductivity, I realize that it is a subject to itself...

Homework Statement It's not a homework problem, but an engineering problem I try to solve before I delve into experimentation :smile: I have a source of heat (SSR - a solid state relay) that's well thermally coupled to the inside of a steel box. The thermal resistance between the SSR and the...

Homework Statement A copper tube, of internal radius 6.959mm, overall radius 7.975mm, thickness 1.016mm, contains water at 68 deg Celsius, and is present in a room with an ambient temp of 26.65 deg Celsius. If the tube is 1000mm long, what will be the rate of heat transferred from the...

Homework Statement So, we have ice at a steady state, and above it is Air at -5.2 celcius, and below it is water at 3.98 C. The total depth of the ice and the water is 1.42m, and they want us to find the thickness of the ice. The thermal conductivies (k) of ice and water are 1.67 and 0.502...

I have a problem. I am designing a probe to first be put through a furnace for 5 minutes (Temp: 1030C) and then straight into a lead bath (Temp: 530C for 3 minutes). I need to be able to calculate the required thickness of insulation. For the formula k=(Q/t)*((L)/(A*ΔT)) I know ΔT as I...

Homework Statement The bulk phonon mean free path between phonon collisions for Umklapp process of a crystal is 30nm. If the crystal is of size 70nm, what is the effective mean free path that should be used in the equation for thermal conductivity? Homework Equations \kappa =...

Is there a way to convert thermal conductivity to the diffusion coefficient? Or is there a way to use the thermal conductivity in Fick's Law?

Hi all, I remember reading somewhere that Cast iron in general has a uniform thermal conductivity k of approx. 47-55, and this remains the same for a wide range of temperatures, im not sure if this is correct, if anyone has any information on this subject, that would be great, if i could...

thermal conductivity chart. "K" can someone tell me where i can find the thermal conductivity chart, K it's in the format of J/s m C

I need Info...! Homework Statement I need information on the thermal conductivity of gas . thank you so much . Homework Equations The Attempt at a Solution

In a thermal conductivity table, what does the temperature column represent in respect to the given coefficient "K" ? E.G http://www.engineeringtoolbox.com/thermal-conductivity-metals-d_858.html does it represent the heat capacity of the material?

I think the answer is yes, but I just wanted to check. If you have several sheets of different material, is the total thermal conductivity the sum of the individual thermal conductivities?

Uhmm.. i faced some problem with my experiment of finding the thermal conductivity of glass..i hope that someone can help me. May i know the extimation of the thermal conductivity of a boiling tube?? isit the same as the thermal conductivity of pyrex glass?? when i want to find the radius...

For my advanced higher physics investigation I've been given the topic of thermal conductivity. Basically I am going to investigate the thermal conductivity of different metals and compare them to the electrical resistance of the metal as I believe that those with low electrical resistance...

Homework Statement Solid cylindrical copper rod 0.2m long has one end maintained at temperature 20K, other end blackened and exposed to thermal radiation from surrounding walls at 500K. As the rod is insulated, no energy is lost or gained except at the ends of the rod. When equilibrium is...

Does the k value have any relationship with the temperature of the wall (use of the word wall becuase that is what the k value is mostly used with).

Hello, Assume that we have a pipe flowing with air of around 80 degrees F surrounded by air of approximately 140 degrees F. The pipe can be made out of three materials: Aluminum, Mild-Steel, and Stainless Steel. What material would it be best to use for the pipe in order for the air flowing...

I had the following question on a Physics Quiz and I am wondering why the answer is D. When you walk barefoot in a room, the floor feels cooler walking on a tile floor as compared to a wooden floor because A) tile has a smaller specific heat than wood. B) tile has a larger specific...

Someone once told me that almost all alloys have poorer thermal properties then their component metals. Is this true? I want to have a little experiment but I don't want to do it if I know all the results will be crap.

Is there any direct relationship between these 2 properties of a matter?

A cylinder with a piston is filled with ideal gas. The gas temperature is held at 500K. The cylinder is heated by an oven through a square metal rod connected between the oven and the cylinder. The rod has sides 2.5cm and length 2m. (a) If the oven is held at 1300K, and the heat current...

Hello. I just wanted to know if a material in the LIQUID state has a higher thermal conductivity than the same material in the SOLID state. I am thinking specifically about the metals, but I suppose it should be the same for non-metals (or not?).

Hi there,...this isn't homework..its more to my practical...anyways...from the attachment given..that is the first page of my practical guide...the problem is...on the procedure part...it asked me to plot a graph of lg temp againts t ...if i do so...how do i get the thermal conductivity of glass...

Hello, This is a homework problem for my Introductory Physics(no calculus) class but it's relatively simple so I opted to put it under high school. First I'll state the problem then my thoughts. A copper rod (k = 390) has a length of 1.5 m and a cross-sectional area of 4.00*10^-4 m^2...

Hi, i would appreciate any help i could get on this, thanks. I'm stuck on part of a biomechanics assignment which is to work out the thermal conductivity of neoprene. I've done this part but am having difficulty on the following question; "Using the value that you have obtained for thermal...

I need a simple method of measuring thermal conductivity of liquids for a school project. I have access to the school's science labs, so I can get the basic equipments (hopefully). All I need is a method of measuring thermal conductivity.

Please Help! Thermal Conductivity :eek: Hi. I need help with the thermal conductivity units. I took the slope of a Natural log(temperature change) Vs. Time graph ( degrees Celsius/unit time) and I need a conversion to Watts per Meter Celsius. If anyone could help that would be great since I...

Hiya! The thermal conductivity al Al is twice that of brass. Two rods (1 Al and the other brass) are joined together end to end in excellent thermal contact. The rods are of equal lengths and radii. The free end of the brass rod is maintained at 0 degrees C and the Al free end is heated to...

Hi... there is a question i can't figure out. "A 400-g stainless steel tea kettle containing 500g of water is on top of the stove.The portion of the tea kettle that is in contact with the heating element has an area of 0.005m^2 and is 2.5mm thick. At a certain moment,the temperature of the...