What is Thermal: Definition and 1000 Discussions

A thermal column (or thermal) is a column of rising air in the lower altitudes of Earth's atmosphere, a form of atmospheric updraft. Thermals are created by the uneven heating of Earth's surface from solar radiation, and are an example of convection, specifically atmospheric convection. The Sun warms the ground, which in turn warms the air directly above it. A thermal is a rising mass of buoyant air, a convective current in the atmosphere, that transfers heat energy vertically.

View More On Wikipedia.org
Recent contents Top users
  1. I

    Thermal Expansion: Solving for Temperature Change

    Homework Statement A hole in an aluminum plate has a diameter of 1.178 cm at 23 degrees Celsius. (a) What is the diameter of the hole at 199 degrees Celsius? (b) At what temperature is the diameter of the hole equal to 1.176 cm? Homework Equations The coefficient of linear expansion (α)...
  2. K

    Thermal equilibrium through radiation and Stefan Boltzmann

    Hey Guys, so I had a longish discussion with colleagues and on reddit about thermal equilibrium and the sun and how you cannot heat up anything above the surface temperature of the sun using clever mirrors and stuff. However, somebody came up with Napkin calculations of the Stefan Boltzmann...
  3. L

    Is the Distance Between Bodies Affecting Thermal Contact in Ansys WB14?

    Trying to model a thermal contact between two faces. The plan is to get the heat flowing from the right part to the left part with a temperature BC on the right and convection on the left. At the moment the left part stays in the initial temperature so the contact obviously doesn't work. I...
  4. C

    Thermal Insulation for usage upto 1700 C

    Does anyone knows any thermal insulation material which can be used for use upto 1500 to 1700 degree Celsius?
  5. K

    Accurate Formulas on Thermal Expansion

    1.Homework Statement . Can someone give me more accurate mathematical models on thermal expansion? for example, linear expansion. 2.Relevant equations L=L0(1+α∆T) this equation is not accurate. for example. When an object 100m long at 0oC (example: aluminum, α=2.4x10-5) is heated to...
  6. Z

    Thermal expansion olympiad problem

    Homework Statement I only know volumetric expansion and linear expansion which require the coefficient constants that are not given in the problem. I also read somewhere that the mass remains constant during thermal expansion or is this false? The problem is attached pls take a look at it...
  7. T

    Stiff material with low thermal conductivity

    Hi, i'm searching for a material with the following properties: - high stiffness - low thermal conductivity - temperature resistance up to 150°C (not getting too soft at 150°C) - no low friction coefficient (so no PTFE) - good fracture behaviour (so no glass, ceramic) - cheap I've...
  8. T

    What has thermal energy but not heat? (and vice versa)

    This isn't homework, so i thought it could go here. 1) What has thermal energy but not heat? 2) What has heat but not thermal energy 3) What effects angular momentum?
  9. E

    How to calculate thermal exchange rate of water inside Pex piping.

    How can I figure out how to calculate the heat/cooling exchange rate of water inside pex tubing? I want to build a ground source cooling system simular to a chiller system but I want a closed loop system. My game plan is to pump ground water into a holding tank that is constantly flowing ground...
  10. DaveC426913

    Heat energy and thermal energy

    My editor friend is questioning the following passage in a book. Does this sound right? In particular, they seem to be making a distinction between "heat energy" and "thermal energy".
  11. Z

    Thermal dynamics - Metals on Engine Components

    I have some car engine related questions, but basically just physics. -Do different specific heat capacities have anything to do with how certain materials resist heat? I know that on some engine compartments there is gold wrapping because it resists heat best, but it has a low specific...
  12. D

    Determine the thermal effieincy of a heat transfer process

    Homework Statement determine the thermal effieincy of a heat transfer process where the following data has been used Input=3kW 1.7 litres of water have been heated from 313K to 375K in 2.5 minutes specific heat capacity of water= 4.19kj/kgK Homework Equations Thermal efficiency=...
  13. M

    Thermal exchange calculations between water/glycol

    I am trying to determine the expected heat exchange between flowing ground water in gravel/clay soil (that runs on top of blue clay) and glycol fluid in plastic pipe (1 1/4"). For my current interest, estimated ground water temperature of 60 degrees seems best. I am trying to determine the...
  14. S

    Thermal equilibrium - Entropy driven

    Hey there. We are struggling with a problem from an old exam about statistical mechanics. I hope you can help us or give any clues. Here is the problem. Homework Statement A chamber is divided by a wall into two sections of equal volume. One section of the chamber is initially filled by an...
  15. T

    Calculating Thermal Energy from Passive Solar Heater

    This is for a physics finals project. So it's not really a homework question. But I didn't know where else to post it and I need immediate help. I have made a passive solar heater out of pop cans and I need to find out how much energy (thermal) is produced. I know the equation for thermal...
  16. D

    Confusion in thermal radiation concepts - infrared, microwave, etc.

    Microwaves heating is often referred to as dielectric heating, but I'm not sure why this seems so special to specify of all the different thermal radiation frequencies. Doesn't infrared heat the dielectric material as well in a similar process? Isn't radiation heat transfer common for a wide...
  17. Z

    The physics behind the thermal light quantum imaging?

    Does it indicate that the " spooky action(correlation)" even can be found in classical level, where entanglement is hardly can be built?
  18. D

    Thermal Physics: Dry Steam Heat 200g Water from 25°C to 95°C

    Homework Statement Dry steam is used to make a cup of coffee by bubbling it through water. If the steam is at 100°C, what mass of steam must be used to heat 200 g of water from 25°C to 95°C? Homework Equations Not quite sure but I think: Q= mCΔT Qcold=-Qhot The Attempt at a...
  19. E

    Thermal gradients in electrical paths of thermocouple conductors

    I recently inherited a problem related to temperature measurement. Thermcouples (d- and k- type) are being used in a high-pressure, high-temperature environment, with the measuring junction suspended in an electrically-insulating solid. The leads of conductors A and B extend out of the...
  20. J

    Need help on Thermodynamics problem: thermal expansion to be more specific

    Need help on Thermodynamics problem: thermal expansion to be more specific! A steel ring with a 2.5000in- inside diameter at 20.0°C is to be warmed and slipped over a brass shaft with a 2.5015in outside diameter at 20.0°C. Part A: To what temperature should the ring be warmed? Part B...
  21. S

    Thermal properties of materials

    Hey came across this question in my physics textbook. If the surface of a material is under compression, is it hot or cold relative to the body of the same piece of material? Unfortunately their explanation doesn't make any sense what so ever! Would anyone like to give an explanation that makes...
  22. B

    What is the engine's thermal efficiency?

    Homework Statement A heat engine using 110g of helium as the working substance follows the cycle shown in the figure. http://session.masteringphysics.com/problemAsset/1074114/5/19.P59.jpg What is the engine's thermal efficiency? Homework Equations n=W/Q_h The Attempt at a...
  23. D

    Thermodynamics - Thermal Conductivity + Heat Flow

    Homework Statement The brick wall of a building has dimensions of 4m by 10m, it is 15cm thick with a coefficient of thermal conductivity of 0.8 (Wm^-1C^-1). (a) How much heat flows through the wall in a 12-hour period when the average inside temperature is 20 C and the average outside...
  24. K

    Any Tips for Coupling Neutronic and Thermalhydraulic Codes?

    Hi there, I'm going to couple WIMS & CITATION as neutronic codes with PARET as an thermalhydraulic code. Please let me know if there is any resources, papers or tips and tricks to do so. Thanks
  25. S

    Planning an Experiment: Excellent Thermal and Electrical Conductors

    i have to plan and design an experiment based on this outline: " excellent thermal conductors are also excellent electrical conductors" could i get any ideas please?
  26. S

    Very basic questions regarding thermal energy and radiation.

    So we were studying about different types of heat transfers, conduction, convection, and finally we learned about radiation, it was sort of confusing, so I am going to write stuff, and hopefully someone can see what i wrote and see if its correct. basically the book says 'Radiation...
  27. T

    Defining Thermal Energy: Understanding the Concept and Its Various Forms

    How would someone define thermal energy? My view is that it is the internal energy of the object e.g potential and kinetic energy. But from what I understand it can also be the energy transferred from one object to another, this is where I get confused. Dose the term thermal energy aka heat...
  28. S

    Thermal properties of ice cream

    i need some conceptual help for my final year project... what are the thermal properties of ice cream?? Specifically the thermal conductivity and latent heat and the relation of it's variation with temperature... i'll be adding a copy of my abstract for better understanding. oh and yeah I'm a...
  29. R

    Thermal contact final temprature

    Homework Statement The following is a worked problem from my textbook: Consider two masses, with initial tempratures T1 and T2 are placed in contact and isolated from their surroundings. They are CV1T1 + CV2T2 = CV1Tf+CV2Tf This equation can be solved for the final temprature T_f =...
  30. N

    Thermal Expansion - Both rule and rod

    Homework Statement A brass rod's length is measured at 20.0 degrees C with a metre steel rule. The length of the rod is determined to be 0.5260 m. The measurement is repeated at 61.6 degrees C. Taking into account the expansion of the rule and rod, what is the new measured length in metres...
  31. G

    Question on Thermal Physics. [it feels impossibly difficult to me]

    Homework Statement This question has got me REALLY confused. I'll be thankful for any help. I don't even know where to start, though I'll mention what my thoughts were. Q. A jeweller wishes to harden a sample of pure gold by mixing it with some silver so that the mixture contains 5.0% silver...
  32. F

    Thermal Properties - Specific heat.

    Homework Statement A well lagged calorimeter of mass 120g contains 200g of water and 50g of ice, initial at 0°C. A jet of steam is blown through the water until the water temperature reaches 30°C. Calculate the mass of steam that must condensed. The specific heat capacity of Copper...
  33. E

    Thermal expansion of brass and iron rings

    A brass plug is to be placed in a ring made of iron. At 10°C, the diameter of the plug is 8.731 cm and that of the inside of the ring is 8.719 cm. a) They must both be brought to what common temperature in order to fit? b) What if the plug were iron and the ring brass? formula for...
  34. L

    Thermal Equilibrium - in a microwave?

    hi, i don't quite know how to pose this question but i'll try my best. if you have an object and heat one end of it, energy will move from an area of high energy, to an area of low energy. By this method, heat transfer will stop when all regions of the object are at the same temperature...
  35. N

    Thermal hydraulic design of nuclear reactor core

    By a simple procedure , what should I do when I'm going through the thermal hydraulic design of nuclear reactor core...? .. I put initial guesses for the core dimensions ( fuel , clad , gap , length) initial guess for the fuel element pitch desired power ... I've found q'' critical heat flux...
  36. S

    Heat of vaporization ( thermal physics) helppp pleasee ?

    A student suspects that the power rating on an immersion heater is 50 W but he is not sure.He sets up an apparatus as shown. After the liquid has been brought to its boiling point, he finds that 3.5g of vapor escaped each minute through the outlet tube.The boiling point of the liquid is 80...
  37. N

    How Does Temperature Affect the Thermal Conductivity of UO2?

    I want to calculate the average thermal conductivity of UO2 by : 1/(To-Tf) * ∫To->Tf dT K(T) any one can provide me anything about the thermal conductivity of UO2 as function of temperature or any measured data in a range of temperature.
  38. W

    Programs Which Engineering Major Is Best for a Career in Thermal Energy?

    Hello, My apologies for making my first post a question but I was wondering if anyone could suggest an engineering degree which would be most suitable for a career with energy, specifically thermal energy and external combustion systems. I was technically a junior and had to take an session...
  39. F

    Convert kinetic energy into thermal energy

    Hi, I need a way to convert kinetic energy into thermal energy as well as the specific heat of the entire Earth's atmosphere. The idea is to see if the heat generated by many meteoroid fragments could possibly account for any climate change. Thanks.
  40. K

    What is the difference between heat and thermal energy?

    Postulate a parcel of air within the larger atmosphere. The air above the parcel is cooler than the parcel, while the air below it is warmer. The parcel is emitting photons to both the overlying and the underlying layers of air and simultaneously absorbing photons from both layers. Both sets...
  41. F

    How much thermal energy it takes to raise the temperature

    It's not really homework, it's more of my own testing of a hypothesis, but I don't really know where else to put it. I need a way to convert kinetic energy directly to thermal energy as find out how much thermal energy it takes to raise the temperature of the atmosphere 1 degree, or I guess...
  42. S

    How does heat transfer occur in different materials?

    I learned that solids conduct heat by vibrating and thus transferring the energy from one particle to another particle. However, my teacher gave us a question: two metal rods of different material are placed in a fire. one of them turns red hot at the end while the other remains silver coloured...
  43. R

    Thermal physics. Entropy's functional dependecy

    Homework Statement I'm reading Kittel&kroemer's Thermal physics. How can I know Entropy's functional dependency? Author assume entropy's functional dependecy without explanations and derive some equaltities. So I can't follow it. N the number of particles. U Energy of the system. V. volume of...
  44. A

    A doubt regarding the proof of kirchoff's law of thermal radiation

    In the proof that I have studied, there is a Isothermal cavity that behaves as a black body. there is another small opaque body inside the cavity at the same temperature with emissivity e, absorptivity a and area s. now the irradiation on the small body is Eb = σ times T raised to 4. now the...
  45. A

    Radial vs circumferential thermal stress

    Hi there I was wondering if someone could give me some insight on the following question. Suppose you have a radially asymmetric heat flux in the outer surface of a pipe. The inner surface is cooled. This will give you two temperature gradients; one across the pipe thickness and one along...
  46. T

    Fick's Law (Schroeder, Thermal Physics Page 47)

    This isn't a HW problem - I am just having a hard time following one of his examples. On page 47 near Eq. 1.71 he says "As a quick example, consider a drop of food coloring added to a glass of water. Imagine that the dye has already spread uniformly through half of the glass. How long would...
  47. A

    Where does the (5/2) come from in calculating thermal energy of diatomic gas

    So I am doing a second year thermodynamics course and would like to know. Do we just have to remember (5/2)PV for a diatomic gas, why is it 5/2 and also what is it for a monatomic gas. Also would we have to remember more complex ratios for exams? Cheers
  48. D

    Thermal energy to be dissipated in an hour

    Homework Statement During the game, the metabolism of basketball players often increases by as much as 30.0 W. How much perspiration must a player vaporize per hour to dissipate this extra thermal energy? Assume that perspiration is simply pure water and that perspiration starts at...
  49. G

    What is the significance of thermal voltage in semiconductors?

    Hallow! For real it's not clear to me on how the thermal voltage in a semi-conductor is established... Can anyone help?
  50. N

    Finding Final Temp. Distribution After Thermal Equilibrium

    The above diagram shows the problem description. I have to find the final temperature distribution after thermal equilibrium. I am assuming that the thermal energy is conserved but not the temperature.(Correct me if I am wrong) Energy of the materials at initial state is (Refer Image) For...
Back
Top