Why it's not possible to recover energy from temperature ?

neufneufneuf

I would like to know why it's not possible to recover energy from this system ? Gas is in a cylinder and it turn at a very high angular velocity (constant) for have a difference of density inside the cylinder. For me, P2 > P1 there is a torque on the square object. Even high angular velocity is difficult to reach, it's possible to think with small temperature. No gravity here. If there is friction, this will add temperature that can be recover. If cylinder turn at the same angular velocity than gas, there is not friction from cylinder. The black shape can be aerodynamic for limited friction. Theoretical physics says it's not possible even in theory, so here I don't find the error.

image: maybe easier like that, angular velocity X is very big, enough for change the density of gas, angular velocity Y in contrary is low and recover energy from temperature. P2 > P1, so a torque must exist, no ?

Maybe it's better to turn black shape like gas, like that no friction, the system will "vibrate" around Y, energy can be recover from this axis. A piezo generator can accept this great vibration I think.

With a radius of 20 m, the system must turn at 100 rpm. This generate a 500 m/s necessary at a standard temperature. At this speed a mechanical system can recover energy from vibration. Sure, it's not easy to built but is it impossible ?

dlouth15

It is possible to recover energy in the form of work from temperature or, more accurately, temperature difference. Look up heat engines online.

neufneufneuf

All systems I saw are with a difference of temperature, here no difference and no state change (gas->liquid). It's not possible with only one temperature ? Have you understood my system ? All can be turn at the same angular velocity like that no friction. Density of black shape can be like local gas if it's necessary. The system like that "vibrate" at Y point, no ? When I recover energy, this is the energy from temperature and from the centripetal forces or it is only the centripetal forces ? The axis X must be "free" enough for allow Y to "vibrate".

Like the system is a gyroscope, if forces appears at one plan this create torque in another plan, so centripetal forces works or not ?

dlouth15

I can see what you are trying to do. I'm not sure how gas would behave in such a system. Why do you think there will be more energy obtained from the system than is put in?

neufneufneuf

No, recover energy from temperature only. Here, I think the energy come from the centripetal forces (these forces need energy) but I thought the energy of temperature decrease in the same time, but not. In fact, all energy come from centripetal forces, I understood.