doesn't that formula depend on absolute temperature like kelvin
or so? where zero degree is minus 459 degree F or minus 273 Celsius. the
ratio of expansion should be something like: inlet air: 20 degree Celsius
(68F) or 293 Kelvin outlet air: 50 degree celsius (122F) or 323
Kelvin then 323 over 293 for a change in temperature gives then the
Volume change of more like 1.2
there is some additional expansion due to the pressure
difference.
Regards
Marko
I started finally welding my engine mount for my turbo rotary
long ez
here are a bunch of excel numbers:
Inlet temp in
degree: |
Outlet temp in
degree: |
Change in |
F |
C |
K |
K |
C |
F |
volume |
68 |
20 |
293 |
303 |
30 |
86 |
1.03 |
68 |
20 |
293 |
313 |
40 |
104 |
1.07 |
68 |
20 |
293 |
323 |
50 |
122 |
1.10 |
68 |
20 |
293 |
333 |
60 |
140 |
1.14 |
68 |
20 |
293 |
343 |
70 |
158 |
1.17 |
68 |
20 |
293 |
353 |
80 |
176 |
1.20 |
68 |
20 |
293 |
363 |
90 |
194 |
1.24 |
68 |
20 |
293 |
373 |
100 |
212 |
1.27 |
68 |
20 |
293 |
383 |
110 |
230 |
1.31 |
68 |
20 |
293 |
393 |
120 |
248 |
1.34 |
-----Original
Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net]On
Behalf Of Al Gietzen
The ratio should be more like 1.6 to
1.8. Do the math - air expands directly proportional to temp - so in at
about 80 F and out at about, say, 130 to 140; gives a ratio of
1.7.
Al
|