Fluidyne Design Info - Page 4

 Jim Wilkins wrote:

You're a bad influence - and perhaps a very big help. :-)

Thank you!

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

  Jim Wilkins wrote:

Thanks for the link - I filled out their form and (may) have a sample on
the way sometime during the coming week. I have a friend here in Des
Moines who (among other things) rebuilds gas struts and I'll pick his
brain in the next week or two - and perhaps talk him into machining the
gate valve and linkage for this critter.

The friction figures for the Airpot actuators are impressive!

This is beginning to look like as much fun as I was afraid it might. :-)

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/

 
I have been thinking about this too.
Absolute pressure in kPa right - but is this inside the engine and it
will be a gradient from the hot side to the cold side - it seems to
me.
Absolute temperature in Kelvin right - again this will vary from the
hot side to the cold side
n moles of the gas - I think this will be constant inside the fluidyne
engine unless the water boils and adds some more gas, but lets pretend
this dosent happen because we have a good insulator float.
R is the gas constant
nR is constant throught for this fluidyne engine - ok

 mpate@oscintl.com wrote:


Right - I think this is probably a good working hypothesis (especially
for fluidynes operating at lower temperatures).

Not so pretending makes calculations so messy that it'd be tempting to
say "to hell with the whole thing". Let's continue this pretense until
we find a pressing need to fold in all that complication. I think we
probably have a reasonable first approximation without it.


Right - by declaring both n and R to be constants, we've said that their
product, nR, is a constant. By taking note of the starting values for
P,V, and T and calculating the value of the nR product, we've set
ourselves up to not need to determine the number of moles of gas nor
specify/determine an exact R value for the particular gas (mix) that
we're using.

It's a useful and convenient simplification. I like those.

--
Morris Dovey
DeSoto Solar
DeSoto, Iowa USA
http://www.iedu.com/DeSoto/