Compressor "Tout" - Need mathematics help

[Dean]

See http://www.gnttype.org/techarea/turbo/turboflow.html, about half way down the page.

In figuring out the "Tout", how do I use the "0.263"?

 

[Steve Wood]

Use a calculator that has a Y to the X key.

punch in 2.373, hit the Y to the X key and then punch in .263.

Sorry I don't remember how to type Y superscript X here.

 

[Dean]

Don't have one.


I did find this, however: http://www.scientificcalculator.com/, but I would still like to know how it works. I am trying to put the entire calculation on an Excel spreadsheet so that I can plug in different values and see the data.


:-Dean

 

[Steve Wood]

well, using that calculator-

punch in 2.373, then hit the Y to X key, then punch in 0,263 and hit the equal key....should get 1.255 and a bunch more decimals.

Then do -1 + 1.255= 0.255/.72 which = .354

Then .354 x 530 = 187

Finally 530 plus 187 = 717





Now, if you want me to tell you how to do exponents in Excel, it has been too long and I am sure there is a spread sheet guru around here that do it quicker than I can relearn it!

 

[S10xGN]

Hey, I can do that! You need cells A1:B6

• A1: type in Tin:
• A2 type in Pout
• A3 type in Pin:
• A4 type in efficiency:
• A5 type in Tout:
• A6 type in (formula) =B1+460
• B1 user to enter value for Tin
• B2 user to enter value for Pout
• B3 user to enter value for Pin
• B4 user to enter value for efficiency
• B5 type in (formula) =B6-460 this will be youy computed value for Tout
• B6 enter (formula) =A6+(A6*(-1+(B2/B3)^0.263)/B4)

It's not "pretty" but you can add on from here.

 

[Dean]

Excell:

=POWER(number, power)

 

[Dean]

S10xGN, that's kinda what I'm doing, except also all the calc's to get all the necessary points (n, V, P/psia, T/Tin, etc.) computed by just inputing the known data variables (CID, Max RPM, Atmospheric temp & Pressure, etc.). The POWER(number, power) takes care of the current hurdle... we'll see what's next.


:-Dean

 

[JDEstill]

Dean, I've already got a spreadsheet that does all of the calcs. The link is at the bottom of the page, very last line, easily overlooked:
http://www.gnttype.org/techarea/turbo/turbocalcs.xls

Unless you just want to go through it all as a learning exercise...

John Estill

 

[Dean]

Hehehe... yeah, just saw that ~5 minutes ago.

I got to reading it, got lost due to not understanding the calcs, and started putting calcs together to make me understand. it was a great learning exercise.

Thanks,

:-Dean