Questions tagged [adiabatic]

Thermodynamic processes that occur without exchanging heat between the system and its environment.

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Why does an adiabatic process become an isothermal process when D.O.F. are high?

Say that during an adiabatic process, the pressure changes from $p_0$ to $a*p_0$, and let the heat capacities ratio be denoted by b ; using the basic adiabatic relations for an ideal gas, we can find ...
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Adiabatic Approximation, Solving the Schrödinger equation

In the adiabatic approximation one looks at the Hamiltonian $$ H_0 = \sum_{i = 1}^{N_e} \frac{\vec{p}_i^2}{2m_e} + \sum_{i < j} \frac{e^2}{|\vec{r}_i - \vec{r}_j|} + \sum_{k < l} \frac{Z_k ...
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Why is $dE = C_V dT$ for an ideal gas, even when the process is not constant volume? [duplicate]

I have come across the following derivation for the "equation of an adiabat for an ideal gas" in many textbooks. The following steps are referenced from a separate question: dE=dQ+dW dW=−pdV dQ=0 ...
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Can two quasi-static adiabates intersect? [closed]

I saw a question in my physics book that I've been trying to understand lately. The question is simple: given two quasi-static adiabatic curves, could you find a point of their intersection? Also, ...
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Calculating final pressure in irreversible adiabatic compression

I am trying to solve the following question. A gas is enclosed in a cylindrical can fitted with a piston. The walls of the can and the piston are adiabatic. The initial pressure, volume and ...
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Adiabatic flame temperature of ethanol in high pressure environment

I'm building a rocket engine and need to know the temperature of the gases inside the combustion chamber (ie the stagnation temperature). The combustion chamber pressure is 5 atmospheres. The ...
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Why does the temperature have to change when there's no heat loss in an adiabatic expansion?

Adiabatic expansion is known to cool gases to a substantial temperature and it's caused by pressure drop. Now if I have a tank full of an ideal gas (nitrogen) at high pressure and temperature, and I ...
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What is the difference between arriving at the 'avoided crossing' point of a two level system adiabatically and non-adiabatically?

In the simplest case of the 'avoided crossing phenomenon' we can assume a two level system that its eigenstates $E_1(n)$ and $E_2(n)$ are functions of some continuous variable n, and there is some ...
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Reversible vs. Irreversible Expansion

Suppose I have a gas in a piston expanding adiabatically against atmospheric pressure. If I do this reversibly, the final state is uniquely specified by the final volume $V_F$ of the gas. What ...
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Why the entropy change is not zero in the irreversible adiabatic process?

Why the entropy change is not zero in the irreversible adiabatic process? while it is defined as the integral of the heat added to the system over its temperature
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Hannay's angle for a spin half interacting with a magnetic field that varies adiabatically over time

Does it make sense to talk about the Hannay's angle for a magnetic moment with spin 1/2?
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Does adiabatic quantum computation require the initial and final ground states to be non-orthogonal?

Background At a recent talk, I was told by the speaker that it is not possible to adiabatically transfer from one ground state $|\psi_0 \rangle$ to another $|\psi_1 \rangle$ if these states are ...
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Understanding Adiabatic Processes in a practical sense

We all know the basic understanding of the adiabatic phenomenon: ideal gas expands and cools, compresses and heats up. Now by expand, let take a quick look at a scenario: let assume there is a tank ...
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Calculate the work for moist air adiabatic expansion and compression?

( During expansion some water vapor condenses and is removed from the system. ) More details: Initial conditions: t 25C, p 1013 mB, humidity 100%, then expansion to ~ 450 540 mB through the double ...
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Adiabatic Expansion of Air blown from mouth [duplicate]

Why is the air blown from our mouth of different temperature as the size of the opening of mouth changes?
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What is quasi-static process?

What is the formal definition of quasi static process? I am accustomed with it a bit intuitively, i want to know the formal definition of this. At some source I found the definition of somewhat ...
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Can $PV^\gamma$ be treated as an entropy function?

In a reversible adiabatic process, $PV^\gamma=\text{const.}$ but reversible adiabat $\iff$ isentrope so does that mean $PV^\gamma$ can be treated as a function for entropy?
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Deduce if path is adiabatic from the state space

Can we deduce, for quasistatic processes, if a process is adiabatic by purely looking at its path in state space? Take, for example, the process of stirring a liquid to heat it up (adiabatic) and ...
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How to calculate work for irreversible adiabatic processes?

By the first law, we know $\text{d}U=\delta Q+\delta W$ and, on adiabats, we know $\text{d} U=\delta W$. But what is $\delta W$ for irreversible adiabatic processes? Take a thermally isolated ...
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First law needs adiabat definition but adiabat definition needs heat definition in first law

It is usually said that the best formulation of the first law of thermodynamics is that work is path independent on adiabatic paths. From there, you can define the state function of internal energy ...
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Defining internal energy for adiabatically inaccessible states

As is well known, a good way to define the internal energy in classical thermodynamics is to define the difference in internal energy of two points as the amount of adiabatic work from one point to ...
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Thermodynamic process

"During this process, the system is always in thermal equilibrium with the surroundings." Does this statement means the process is adiabatic? Since the temperature of both systems is the same, there ...
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Why is $C_V$ used in this derivation? [duplicate]

In his lecture (26:30-38:40), Shankar derives the adiabatic pressure-volume relationship $P_1V_1^\gamma = P_2V_2^\gamma$, where $\gamma = C_P / C_V$, from the First Law of Thermodynamics $\Delta U =Q -...
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In an adiabatic process, why is it that if work is done very quickly then there is no time for energy transfer to the surrounding?

I don't seem to understand the logic in adiabatic process of how 'if work is done on the system very quickly e.g. compress a piston containing n number of gas particles, there is no time for energy to ...
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What is the meaning of $PV^\gamma=$ constant in an adiabatic process?

In an adiabatic process, heat transfer doesn't occur and hence $\Delta U=-W$ (an increase in internal energy due to work done on the system or a decrease in internal energy due to work done on the ...
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Adiabatic Availability?

In the textbook "Thermodynamics: Foundations and Applications" by Elias P. Gyftopoulas and Gian Paolo Beretta (Dover). In chapter 5, on page 73 (section 5.3) the book says: Adiabatic availability ...
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Intersection of Adiabatic curves

Can two adiabatic process paths intersect on a plot? This question is for both reversible and irreversible processes. There are some answers for this question on Quora, but they mostly address only ...
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Adiabatic expansion Vs pulling a syringe after closing its mouth

I've read that adibatic expansion always results in a decrease in temperature. Since temperature is average kinetic energy, I don't get how kinetic energy can decrease when we increase the volume. ...
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Adiabatic closed system work

The closed system work PdV is path dependent but it is path independent for an adiabatic process as can be shown by applying conservation of energy on a closed system (dQ = dE + PdV),here dE is change ...
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Adiabatic Process: Fast or Slow? [duplicate]

I have always used adiabatic process to be fast, so that the system doesn't get enough time to exchange energy in the form of heat. But as I was reviewing adiabatic process from the Resnick, Halliday, ...
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Name of this type of cooling system?

If you pump around air in a cyclic tube at a high speed, and one part of the tube is narrower than the rest of the tube, the air flow will have to increase in speed when it enters the narrow part in ...
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Thermal expansion of solid body and calculation of work produced

From the information about thermal expansion on Wikipedia, I found that if I heat a steel rod that's 1-meter in length and 1-cm in diameter steel rod to 100 degrees Celsius, then it will expand by ...
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Internal energy of a reversible adiabatic process

what happens to the heat transfer and the internal energy in a system that undergoes reversible adiabatic process back to its original state. Bearing in mind that heat $Q$ was transferred at the ...
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Internal Energy Change for a free adiabatic expansion

I was watching a video from mitocw in which the professor wrote that: dU = dw(reversible) If we consider a free expansion, then the work done must be 0. The process is also adiabatic implying that ...
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Thermodynamics adiabatic transformation

I have the following question as howework, I think I don't have enough information to solve it. Given are $p_1=311$ kN/m$^2$, $T_1=333$ K, $T_2=853$ K. Asked are $p_2$, ratio $V_1/V_2$, and $R$ if ...
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Rigorous Laughlin pumping argument

Is there a way to justify formally the Laughlin pumping argument? It is often argued that the spectral flow of Landau levels while varying the flux inserted through the Corbino ring should account for ...
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Maximum velocity of piston pushed by a gas on adiabatic irreversible expansion [closed]

I am currently studying for my country's IPhO selection process and thermodynamics has to be one of my favorites right now. However I came across a very odd problem that is making me revise a lot of ...
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Can the ideal gas expand adiabatically and irreversely?

Suppose that the ideal gas is expanding adiabatically from the state $(P_1, V_1, T_1)$ to the state $(P_2, V_2, T_2)$ I think this process can be allowed to happen reversibly or irreversibly, but ...
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Entropy change in a reversible adiabatic expansion of ideal gas

Below is P-V curves of 1 mole of ideal gase for temperature 700K, 500K and 300K each. Now I would like to calculate entropy change of the system along the path from (1) to (3), which is adiabatic ...
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Adiabatic processes

Adiabatic process is a process that involves no interactions other than work. What I interpret from this is that change in energy = change in work done. however it is not the case but it’s the ...
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magnetic refrigeration and adiabatic processes

Suppose we have a magnetic material that is well insulated from its environment, and we then ramp up the current in a helmholtz coil that encloses the magnet. We then observe an increase in the magnet'...
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Adiabatic reversible and irreversible process

If I have 2 gases $A$ and $B$ which are at an initial state ($P_1$,$V_1$,$T_1$) and one gas say $A$ is taken through a reversible adiabatic process and the other gas $B$ through an irreversible ...
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Can steam freeze via adiabatic expansion?

Context: At the end of animation movie Steamboy, a huge steam engine's pressure vessel breaks, which results in the escaped steam freezing to ice. I've been thinking about this -- is it really ...
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Question about adiabatic process (in Landau&Lifshitz's book)

In section 11 of Landau's statistical physics part 1, he wrote the following: Let us suppose that a body is thermally isolated, and is subject to external conditions which vary sufficiently slowly. ...
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Adiabatic expansion and first law

So I wanted to know whether the following equation would be correct for an adiabatic process. **adiabatic expansion ** ∆U = -W Adiabatic compression ∆U = W
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End expansion point on overheated Rankine cycle

In an overheated Rankine cycle, the end point of the adiabatic expansion could end inside the dual-phase bell, or on the right. In the first case, the end expansion point falls of course on the ...
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ideal gas adiabatic process

I know how it is derived and here is my concern: $dU=-dA=-d(pV)$ p is not a constant here, it depends on V. So my logic says, ...
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Explanation of the diabatic basis

In Curl Wittig's paper, (J. Phys. Chem. B 2005, 109,8428-8430) on the Landau Zener formula, he defines something called the "diabatic basis" for a wavefunction describing a two state system? What is ...
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adiabatic work done by gas

Suppose we have an adiabatic box with a fixed volume $V$ and contains $n_0$ mol of gas at pressure $p_0$ and temperature $T_0$. Now the box is punctured by a small hole and gas from the outside flows ...
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Transitionless quantum driving for specific eigenstates

Transitionless quantum driving is a concept that was invented by Berry in 2009. In his article on transitionless quantum driving he showed that it is possible to speed up adiabatic evolution of ...