Talk:Adiabatic process

Continental and local scale

can you help me with a continental or global scal in the atmosphere and a local or regional scale

Continental or Global scale would be the Hadley cell and a local or regional scale would be sea and land breezes. Hope this helps!

Perhaps articles like Joule-Thomson effect should be considered as relevant to the topic. --Saperaud 08:04, 22 December 2005 (UTC)

Edit, 2006/01/30

I edited the section on adiabatic heating/cooling. The "coolness" felt when pursing one's lips and blowing on one's own skin is due almost entirely to enhanced convective heat transfer; the actual air temperature drop is so small (due to the tiny pressure drop involved) that if one blows on a thermometer in this manner, there will be a negligible temperature change.

I instead offered the different example of deflating a tire, where the pressure drop is on the order of several hundred KPa (several dosen psi); I have seen frost form on valve stems because of this.

Also added the more extreme heating example of a motorized air compressor operating at higher pressures than a bicycle pump.

Joe Frickin Friday 17:54, 30 January 2006 (UTC)

Very similar effect occurs when looking at a Methonol Cannon, you can observe this phenomenon very easily

added 2006-01-04

in 'Derivation of formula' section equation (3) there is dE = something - shouldn't it be dU ?

Symbol for the ratio of specific heats

I fully realize that the Greek letter gamma (${\gamma }$) is used by physicists and others as the symbol representing the ratio of specific heat at constant pressure to the specific heat at constant volume. However, I would like to point out that thousands of engineers worldwide use a lowercase k to represent that ratio. I strongly believe that this article should mention that fact. mbeychok 00:10, 1 March 2006 (UTC)

Adiabat?

So, what exactly is an adiabat? The article doesn't make this clear. Jonabbey 04:31, 7 June 2006 (UTC)

I belive it is a line on a graph that indicates 0 heat flow along that line, like an isotherm is a line denoting constant temperature.

Correct. An adiabat is a curve on the pV graph where Q=0. An adiabatic process is one that follows one of these curves. An adibat is always steeper than an isotherm. 75.5.254.164 00:51, 11 December 2006 (UTC)

No, an adiabat is a curve with constant entropy (i.e. its an "isentrope"). Q (or δQ) is not a state function, so there are many curves through the same point that could be adiabatic, but only one that is isentropic. PAR 02:58, 11 December 2006 (UTC)

Derivation of TV^gamma-1

The derivation of TV^gamma-1 is a lot longer than the one in my physics text book (Young & Friedman 11th ed.) and doesn't explain what Cv is. I'd fix this myself, but my mathML sucks. 75.5.254.164 00:51, 11 December 2006 (UTC)

We are doing a project on the adiabatic process and we need a lot of help. Can anyone help us? 63.172.1.2 13:42, 28 February 2007 (UTC)Paco and Taco

Something seems wrong to me: Equation (1) states that dU = - δW, whereas first equation below equation (4) states that δW = - p dV = α p dV + α V dp = dU, i.e. δW = dU. Giving that the end of the derivation is correct, there should be a confusion between the physical definition of work (work done by the system) and the chemical one (work done one the system). Equation (1) is valid for physical work definition. Question: is equation (2) valid for physical work or chemical work ? Parey (talk) 08:07, 25 January 2008 (UTC)

Adiabatic Internal combustion Engine

Fountain Powerboats of Washington NC claims to have created an adiabatic internal combustion engine based upon a marinized Chevrolet engine. Though the project has not proven publicly it is really an adiabatic cycle engine it has demonstrated extreme power production. Anyone care to propose how this would work?

Jsmithnc 20:25, 13 August 2007 (UTC)

Discrete Formula

It looks like something is wrong with the final form of the discrete formula derived - if you just plug in the ideal gas law for t2 and t1 and cancel things, you get alpha=-1 always. This can't be right - alpha depends on the degrees of freedom for the particular molecules (ndof/2), and could take on many values. —The preceding unsigned comment was added by 67.161.105.146 (talk) 07:15, August 21, 2007 (UTC)