Stack Exchange Network

Stack Exchange network consists of 174 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [heat-transfer]

Questions relating to the transfer of heat via the mechanism of convection, conduction, or radiation, in forms of systems (or your device) attempting to obtain thermodynamic equilibrium with another system (the environment or your other device)

0
votes
1answer
35 views

Air Cools As It Expands

What is the degree of cooling caused by air flowing from smaller diameter into a large diameter? How much does air cool as it expands? If the air inlet was the biggest hole on the right and the ...
0
votes
0answers
18 views

Please help solve this problem! [on hold]

Fluid with mdot = 0.025 kg/s and Tm,i = 25oC is flowing through a long metal cylindrical tube where the diameter is 0.032 m and the length is 2 m. The surface of the tube is heated with a heat flux of ...
0
votes
0answers
20 views

How to “isolate” thermal resistors when doing a 1D transient conduction question?

I have a system that I can model using a thermal circuit analysis. In this system, I have a hot gas, and thus a convective resistance $R_{convection}$, that heats the surface of material "A" . Then I ...
0
votes
1answer
25 views

Peltier Element - Segregation of the Hot/Cold

Referring to this diagram: How does the height of the P and N components affect heat or cold generated on this thermoelectric element? The idea I keep having is that it seems like the hot and cold ...
2
votes
1answer
45 views

Connect heated copper tube in PVC tube

I have a copper tube that I'm heating (quite a lot) with a torch, I have to connect a PVC pipe in the entrance of the copper and one in the exit (so water can flow through the copper pipe). The only ...
0
votes
1answer
28 views

Temperature not changing in my code for 1-D heat equation: Explicit Scheme

I am trying to solve the following 1-D heat equation with provided boundary conditions using explicit scheme on Matlab. I have been trying to plot the results but I realized that my temperatures are ...
1
vote
2answers
63 views

Wouldn't it be most effective to insulate a house with just an air space?

It is my understanding that of all three states of matter, gases have the lowest thermal conductivity. If this is the case, why are solid materials, such as fiberglass and polyurethane, used for ...
0
votes
0answers
24 views

Numerical Methods For Computational Fluid Dynamics Question

I have a one dimensional heat diffusion equation in spherical coordinates that I have been stuck on for a while. I want to solve this problem numerically and plot it on matlab using the provided ...
4
votes
2answers
89 views

The concept of flux

I find it difficult to understand the concept of flux and field.I have searched the internet and refered a few books.From what I understand, generally flux can be defined as "some quantity per unit of ...
0
votes
1answer
31 views

Conductive Heat Transfer calculation over time

I am trying to heat the oil in a 1/2 inch thick rectangular steel box by using an Insulated heated blanket covered on all 6 faces of the box, the working conditions of the operation are at -50 Celsius,...
2
votes
1answer
38 views

What does stanton mean physically?

In heat transfer, we come across Stanton number which is the ratio of heat transferred into a fluid to the thermal capacity of the fluid. But what does this physically mean and its importance in ...
2
votes
0answers
33 views

hot wire anemometry

Hot wire anemometry can be used to measure the temperature of a wire in fluid flow. The voltage fluctuation across the wire is used in conjunction with an energy balance on the wire to obtain the ...
2
votes
0answers
20 views

Does a closed loop biomass-fired cogeneration/CHP make sense?

I'm working on a project concerning electricity production using biomass, and we have seen that making use of cogeneration is very attractive in order to increase the efficiency of the installation. ...
0
votes
1answer
44 views

Is there any practical way to partially absorb the heat from a refrigeration condenser

I have currently been experimenting with a phase change material to absorb the heat given off by the condenser in a small refrigeration system (about 1/5 hp compressor) and while it does absorb a ...
3
votes
1answer
63 views

What is the most common control method in Underfloor heating?

I am trying to research the common methods on an underfloor heating system that are available in the market. I know there are usually, On/Off control to control the flow of water into the pipe ...
1
vote
1answer
23 views

Operative Temperature in Underfloor Heating?

I am new to the Underfloor heating system, and a bit confused on the terminology for Operative Temperature. Is this the temperature that is measured by the sensor or is this the set-point temperature ...
2
votes
0answers
24 views

How much can a double Peltier stack cool to -30 C?

I need a -30 C freezer. Inside volume 5-30 l. I've seen videos of double Peltier stacks reaching -50 C with one Peltier running at 12V and the other at 5 or 7 V. How big a freezer could such a stack ...
1
vote
2answers
60 views

Adiabatic paths

Can two adiabatic process paths intersect on a plot? This question is for 2 cases- 1.) Can two irreversible adiabatic curves intersect. 2.) Can a reversible & an irreversible adiabatic curve ...
2
votes
3answers
63 views

Why not drive an air source heat pump domestic heating system with an auto engine?

Theses are my thoughts on the question. I can't find an answer to "why not?". It there something I am missing, or are auto manufacturers simply too focussed on cars only? The automotive industry has ...
0
votes
0answers
33 views

Average Composite Wall Temperature

I have a composite wall with two different materials: concrete and steel. The left side of the wall has a hot fluid flowing against it and the right side of the wall has a cold fluid flowing against ...
0
votes
0answers
31 views

Tempreture distribution in a furnace

I am simulating a furnace as follows: Is it possible to capture temperature distribution in this furnace without designing intake fan? Which kind of boundary conditions can replace with intake fan? ...
0
votes
1answer
65 views

Thermal oil in Boiler not reaching desired temperature

The thermal oil Feroline U in Boiler is not gaining the desired temp of 240 Degrees. We have physically measured the temp using digital thermometer at a distance of 20 cm where the boiler temp sensor ...
1
vote
1answer
74 views

how would one calculate the % of heat not absorbed by a heat sink?

I'm planning on building a plant growth chamber inside a sealed/insulated 55 g rain barrel, and I'm trying to figure out how much of the heat from my lights will enter the chamber, and how much ...
0
votes
4answers
104 views

what's the best shape for inducing condensation?

What would be the best ceiling shape for inducing condensation? I'm guessing it would a curve ︶ or V shape, but those are just guesses. (I don't have any background on thermal physics)
0
votes
2answers
30 views

How do I correctly model a building to determine effectiveness of a heat source?

The problem domain You have a shelter that you use in a cold climate, and you want to provide it with some heat to take the edge off the chill. You already have a structure in a location which gets ...
1
vote
1answer
38 views

What about the natural convection heat transfer coefficient (*h*) at low Delta-T?

In a system I am modeling for personal research, I have a sphere (S) submerged in air (A), initially at the same temperature Ts = Ta. Then the temperature of air is slowly increased (or decreased), ...
1
vote
0answers
20 views

Ventilation requirements of a closed housing of a video wall

Our company builds rather large video walls that are driven by computers next to them. In one of our current project the size of the installation is 21 55" displays side by side in portrait mode and 4 ...
1
vote
4answers
65 views

Is it practical to make a solar furnace for small scale metal production?

Solar furnaces using mirrors to concentrate sunlight on a small area do not produce much power - perhaps 1kW per square metre of mirror - but can reach very high temperatures. From the earliest ...
-1
votes
1answer
53 views

Does ground conduct heat? [closed]

Does ground conduct heat or it acts like an insulator ? If yes then whats the conduction co-efficient or convection co-efficient ( in terms of convection heat transfer ) ?
0
votes
0answers
17 views

Nickel Chromium shape and gage

So I am trying to understand to myself the qualitative differences if any for size and shape of Nickel Chromium wire. If I have a system: Assume the following: The fan is blowing at a constant ...
1
vote
1answer
19 views

Heats affect on material permeation?

I know that heat affects material permeation (increasing it); but I have not been able to find much in the way of data other than biologically, on how it effects materials such as plastics. Does ...
3
votes
3answers
105 views

Pasta cooking time

How does time needed for cooking pasta (or any other food) change depending on stove power output (for simplicity, let's say flame size)? If it does... And why. Starting with the point that water is ...
1
vote
1answer
37 views

Why don't we use other substitute of cement while building a roof for thermal proofing?

Cement heats up like crazy. I live in the top floor and the heat is unbearable. Also it has a high carbon footprint. Why still cement is vastly used? When there are so many better alternatives?
6
votes
3answers
180 views

Should we protect our AC's outdoor unit from sunlight?Does it increases the durability of an AC and its refrigerant if it is well shaded?

My AC outdoor unit gets direct sunlight (no shading whatsoever) from morning to noon. Temperature normally soars up to 40 degree Celsius (I am from India). I have two questions: Is this bad for the ...
0
votes
0answers
31 views

Ansys or Solidworks for heat transfer

I intend to simulate heat transfer for the building (greenhouse). And I gonna use conduction through the walls with convention heat transfer (inside air - wall insulation ). After oserving the ...
0
votes
0answers
35 views

Need help in understanding an equation in solidification modelling

I am not able to understand the 2nd equation. These equations are to model a simple solidification of an alloy system, the equations are set on a region which is semi-liquid ( mushy region ) , The ...
0
votes
1answer
27 views

How to Pull Heat Quicker from a Thermo-Electric Cooler using an Aluminum Heatsink

I just purchased an aluminum heatsink that I am using to "wick" away heat from a Peltier; however, I was wondering how I can pull heat from the hot side of the peltier quicker. I have purchased large,...
1
vote
0answers
33 views

Using a Copper Waterblock or Aluminum Heatsink to Cool Water via Thermo Electric Cooler [closed]

I am attempting to create a ThermoElectric Cooler to Chill Water. I have thought of two options as to how I can cool the water: Some limitations of the design: The water is still, not moving. No "...
0
votes
1answer
41 views

Heat loss from the greenhouse to the soil

I need to find heat loss from the greenhouse. I know how to find heat loss through the walls and roof , but what about soil ? how to find amount heat conductivity loss to the soil ? I would be ...
0
votes
2answers
33 views

Heat transfer in a fin with constant volume and given efficiency

Assume we have a cylindrical fin which has the effective length of L and its efficiency is given by the equation: $$η=exp(-0.32mL)$$ where $$m=\sqrt{\frac{hP}{kA}}$$ where P is circumference and A is ...
0
votes
1answer
25 views

Area of Heat Transfer and Carnot Efficiency

Question: a) What is the area of the steel plate interface (in $m^2$) with the fluid conduit if the heat enters the steel plate at a temperature (T1) of 980K? Assume rest of the conduit surface (...
1
vote
0answers
17 views

Does a TXV completely close when there's no thermal load whatsoever?

How is a TXV supposed to behave in a no evaporator thermal load situation (for example, evaporator fan completely off)? Would it completely close, not letting any liquid refrigerant get through (and ...
0
votes
0answers
191 views

Radiation “not working” in Solidworks Simulation

I am just starting out on Solidworks Simulation, and I am trying to set up a simple model to get a grasp on the module. I have a "Bulb" which is emitting thermal power while rigidly attached to a ...
1
vote
2answers
66 views

Blackbody radiation

If we are able to see an object in a certain color,that means it reflects the color.A blackbody is one which has zero reflectivity.Then how come it is not black always?
4
votes
2answers
100 views

Solving heat loss equation associated with solar trough concentrators

My project is about finding the efficiency of solar trough (cylindrical parabola) concentrator that will boil water in a pipe located at the focus (check picture please). In the process of doing so (...
0
votes
0answers
9 views

Operative thermostat influence on heat fluxes

If the heat fluxes in a non-insulated building during the heating period are considered. How these fluxes (Primary energy from the heating system, internal heat gains from people, light and equipment ...
0
votes
0answers
119 views

Can a TXV prevent an evaporator from icing up due to no airflow at all in a parallel evaporators AC system?

I'm new here and i want to begin taking part in the community with my first question ever. Let's pretend that: We have an AC system which features two evaporators in a parallel arrangement placed ...
0
votes
0answers
22 views

How does one resolve/reduce unequal circuit heat load in evaporators?

Typically, evaporators are working by evaporating fluids, using an ohmically heated electrode in them. Here comes the problem that sometimes the heat generation is inequal. How could they be ...
0
votes
0answers
29 views

Best model to describe this scenario of cooling?

I have a block of CFRP (Carbon Fiber Reinforced Polymer) that has defects (back-drilled holes) in it. This sample was exposed to a source of heat for sometime (say 30 seconds) and the source if ...