Register to reply

Recover energy from unique temperature

by Gh778
Tags: energy, recover, temperature, unique
Share this thread:
Gh778
#1
Nov18-12, 02:53 AM
P: 365
Why is not possible to use this simple cycle for recover energy from unique temperature ?

1/ (first drawing) For limited friction I think it's possible to put outside pressure of 10 nPa. The speed velocity of the cylinder is constant, I think it's possible to use small speed like 20 m/s but bigger is the speed bigger is the efficiency. The cylinder has a gas inside. If velocity is constant, this need rotational speed is changing in time but like that it's possible to prevent problem for lost kinetics energy when radius change and problem with frictions. The goal when cylinder rotating is to keep constant the kinetics energy of gas, velocity is constant not rotational speed.

2/ (Second drawing) Or for not change kinetics energy of gas, put inside cylinder an object when pressure is low at bottom. When cylinder move in translation, move out red object and recover energy.
Attached Thumbnails
am2.jpg   edg1.jpg  
Phys.Org News Partner Physics news on Phys.org
'Comb on a chip' powers new atomic clock design
Quantum leap in lasers brightens future for quantum computing
Enhanced NIST instrument enables high-speed chemical imaging of tissues
mfb
#2
Nov18-12, 09:55 AM
Mentor
P: 11,573
The (partial) separation of the gas and/or lifting of the cylinder slows the belt.

You cannot violate energy conservation or the second law of thermodynamics with any setup, unless you discover completely new laws of physics (which will not happen in those concepts).
Gh778
#3
Nov18-12, 10:59 AM
P: 365
The (partial) separation of the gas and/or lifting of the cylinder slows the belt.
so the kinetics energy of cylinder slow down, this lost of energy is in energy of the pressure of gas, is that ?

mfb
#4
Nov18-12, 11:08 AM
Mentor
P: 11,573
Recover energy from unique temperature

You add some energy to get a pressure difference, right.
Gh778
#5
Nov18-12, 11:11 AM
P: 365
So in this case we can change velocity in pressure. Imagine a system like drawing, a solid move in translation at V1, a cylinder with gas inside move in translation at -V2, V2>V1. If after turn some degrees, V2 slow down to V1, we can turn the system around a circle. But the center of gravity has seen V1 and V2 at start not two same velocity, how does it work for compensate all ?
Attached Thumbnails
xc1.jpg  
mfb
#6
Nov18-12, 11:57 AM
Mentor
P: 11,573
I don't understand your setup and your question.
Gh778
#7
Nov18-12, 12:11 PM
P: 365
I'm interesting about the center of gravity. The radius of gas increase in the cylinder so the centripetal forces decrease (mv²/r), the speed of cylinder decrease too, the energy is converted to pressure, so the centripetal forces decrease too. In this case, how the center of gravity don't move even a unique cylinder ?

The setup is to move to the left one solid (masse m) at V1 speed same density of gas and same repartition of density when cylinder is rotating, move to the right one cylinder with gas inside (masse m) at V2 speed. While cylinder and solid move the center of gravity don't change. Until cylinder and solid turn, in a standard setup V1=V2 at start and after, here V2>V1 at start but when rotating V1=V2.
mfb
#8
Nov18-12, 01:41 PM
Mentor
P: 11,573
No, my problem is much more basic:
What happens in the setup? Do the moving parts, after reaching the circle, somehow stick to it? Is that circle a rotating disk, with a fixed center, or completely fixed, or whatever?

If that disk is fixed to some point, you can get forces on this anchor, accelerating or moving the center of mass of your system.

The radius of gas increase in the cylinder so the centripetal forces decrease (mv²/r)
mω^2r
Without a quantitative analysis of the velocity, you cannot tell.
Gh778
#9
Nov18-12, 02:20 PM
P: 365
yes, the circle is fixed at its center only, an arm keep cylinder when it pass near it. The circle can turn freely.


Register to reply

Related Discussions
Energy required for temperature raise - temperature-dependent specific heat capacity Advanced Physics Homework 3
Energy required for temperature raise - temperature-dependent specific heat capacity Introductory Physics Homework 1
Unique λ at which X-ray and electron have same energy Advanced Physics Homework 4
Unique λ at which X-ray and electron have same energy Introductory Physics Homework 0
Data Recover from RAM ? Computing & Technology 7