Thermodynamics, Heat Transfer, differential equals

In summary, the conversation discusses a potential calculation regarding the changing temperature of a beer bottle placed in a water reservoir. The individual asks for confirmation on their equations and whether there are any mistakes in the energy balances. They also mention possible complications with solving the ODE and ask for a response regarding the correctness of their thoughts.
  • #1
al3ko
2
0
Hi there,
first of all:
This is not a homework task or something like that. It is just one of my interests and I want you to check my calculation, if my thoughts are correct or not.
Furthermore I apologize for my incorrect englisch but I am a foreigner.

Okay, now some background information:
Imagine a waterreservoir in the size of a bathtub and a constant watertemperature. You put a beerbottle into that reservoir and you want to describe the changing of the temperature of the beer. Allright. In my opinion, we have two physical phenomens:
1. Heat transfer from the reservoir to the bottle
2. Heat transfer from the bottle to the beer.

Is it right?
Okay, so the first equation should explain the incoming heat energy from the reservoir and the outgoing heat energy to the beer connected with the energy changing of the bottle.
[tex]\begin{equation}\dot{Q}_{res}-\dot{Q}_{beer}=\frac{dU_{botl}}{dt}\end{equation}[/tex]
The second equation bescribes the inner energy of the fluid by incoming heat energy from the bottle:
[tex]\begin{equation}\dot{Q_{beer}}=\frac{dU_{beer}}{dt}\end{equation}[/tex]

I just want to know: Is there any mistake in the energy bilances? This is the basic I have to go on working with. If this is wrong everything else is wrong, too :)

Therefore I just want you to give a short response if my thoughts are right or not.

Best regards
al3ko
 
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  • #2
It looks correct to me.
 
  • #3
Franco_v said:
It looks correct to me.

Hi franco,
thanks for your statement.

I was just a little bit unsure about the first equation with the outgoing power transfer from the bottle into the liquid. [tex]\begin{equation}...-\dot{Q}_{beer}=...\end{equation}[\tex] because that complicates my solving of the ODE so I think I have to do it numerical by Matlab.

Best regards
al3ko
 

1. What is thermodynamics?

Thermodynamics is the branch of physics that deals with the relationships between heat, work, and energy. It studies how energy is transferred and transformed between different forms, and how it affects the properties of matter.

2. How does heat transfer work?

Heat transfer is the movement of thermal energy from one object or system to another. It can occur through three main mechanisms: conduction, convection, and radiation. Conduction is the transfer of heat through direct contact, convection is the transfer of heat through the movement of fluids, and radiation is the transfer of heat through electromagnetic waves.

3. What is the significance of differential equals in thermodynamics?

The symbol "differential equals" (≈) is used in thermodynamics to represent an approximation of the change in a variable. It is used in equations to show that the change in a variable is directly proportional to the change in another variable.

4. How does thermodynamics relate to everyday life?

Thermodynamics is crucial in understanding how various systems and processes work in our everyday lives. It explains how our bodies convert food into energy, how engines and refrigerators work, and how heat can be transferred between objects. It also plays a role in environmental science, as it helps us understand the processes that drive weather patterns and climate change.

5. What is the difference between heat and temperature in thermodynamics?

Heat and temperature are related but different concepts in thermodynamics. Heat is a form of energy that is transferred from a hotter object to a colder object, while temperature is a measure of the average kinetic energy of particles in a substance. In other words, heat is the transfer of thermal energy, while temperature is a measure of the amount of thermal energy present in a substance.

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