×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Thermal Generator

Thermal Generator

Thermal Generator

(OP)
Old Structural here who has forgotten just about all the Thermodynamics I ever knew.

We know that the "sunny" side of a spacecraft can experience temps in the +250F range while the "dark" side is at about -250F.

Why couldn't some type of fluid be boiled on the "hot" side, run through a turbine/generator and condensed on the "cold" side??

For reasons I don't completely understand why not or otherwise NASA probably would have already done it.

Any help out there telling me why?

RE: Thermal Generator

As a first guess I'd say because photovoltaic panels are better for the application.

No moving parts. No fluid to leak. No maintenance needed.

RE: Thermal Generator

> It could, possibly, but the boiling and mass transfer affects the momentum of the satellite, and for many applications, such wobbling is unacceptable.
> The usual issue is not the incoming thermal, but the internally generated thermal, which must be removed through radiation.
> Carrying a non-functional fluid into orbit is every expensive, and a thorough cost-benefit analysis probably rules it out.

TTFN
FAQ731-376: Eng-Tips.com Forum Policies

RE: Thermal Generator

It would be easy to gain heat of the hot side, but difficult to reject heat out the cold side.

Spacecraft despite what science fiction says about space being cold actually have immense problems with shedding heat because it can only be done through radiation (There is no air to convect to).

To create your system you'd need comparatively immense fins on the dark side to get rid of the heat that has been added to the spacecraft. Frankly it just wouldn't be worth it. Most space craft design involves trying to avoid gaining as little heat from the outside as possible which is why space craft are so shiny.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources