Index Circular stirling Stirling program source code Links
Stirling engine design program
Isothermal second order calculation
Developped from the Fortran program, written by William R. Martini
Hover mouse over a text, a button or a diagram for detailed information.
 
 

engine       type:
Click here for more about the GM4L23
number of similar units per engine.


operating conditions:
engine speed,
mean pressure,
operating gas, hydrogen, helium, air or carbon dioxide.
cooling water flow @ 2000 rpm per cylinder
mechanical efficiency, %
furnace efficiency, %
fraction of total gas charge leaking per MPa P per second
temperature specified in: celcius, kelvin or fahrenheit.
inside heater tube wall temperature,
inlet cooling water temperature,
static heat conduction loss
specified static heat conduction loss, watts
metal thermal conductivity, w/cm K
Inputs to calculate volumes and volume changes. -----------
cylinder 1 (hot side = expansion cylinder) ---------------------
 1. cm, diameter displacer cylinder.
 2. cm, displacer end clearance.
 3. cm, crank radius for displacer.
 4. cm, length of displacer connecting rod.

cylinder 2 (compression cylinder or the power cylinder in a gamma) ----
 5. cm, diameter compression cylinder.
 6. cm, power piston end clearance in the compression cylinder.
 7. cm, crank radius for power piston.
 8. cm, length of power piston connecting rod.
 9. crank angle between the crank on displacer cylinder compression cylinder.
10. Angle between the two cylinders. Often 0 or 90 degrees.
11. cm, diameter of displacer drive rod (zero for alpha). Negative means the rod is on the hot side.

Inputs to calculate heat conduction. -----------
12. cm, gap in hot cap (expansion cylinder diameter-displacer diam.)/2.
13. cm, length of hot cap (top of the displacer, above the seal).
14. cm, wall thickness of the hot cap (displacer top).
15. cm, wall thickness of expansion cylinder wall.

heater
number of heater tubes per cylinder.
cm, heater tube length.
cm, heater tube heat transfer length.
cm, inside diameter of heater tubes.
cm, heater tube outside diameter (not used).
regenerator
number of regenerators per cylinder
cm, wall thickness of regenerator housing.
cm, length of regenerator.
cm, diameter of regenerator.
cm, diameter of "wire" in regenerator.
filler factor, fraction of regenerator volume filled with solid
cooler
number of cooler tubes per cylinder
cm, length of cooler tube.
cm, heat transfer length of cooler tube.
cm, inside diameter of cooler tube.
cm, outside diameter of cooler tubes. (not used)
connecting duct
number of connecting ducts per cylinder
cm, inside diameter of connecting duct.
cm, length of connecting duct.

 
Message box
PROGRAM CALCULATED OUTPUTS
Prediction for the whole engine.
power watts       heat requirement, watts      
basic basic
heater windage loss reheat loss
regenerator f.l. shuttle loss
cooler windage loss pumping loss
- ------------ temperature swing loss
net power conduction loss
mechanical friction flow friction credit
- ------------ + ------------
brake power heat to engine
-------------------- ---------------- furnace loss
indicated eff.%= + ------------
overall eff.%= fuel input
-------------------- ---------------- ------------------------ ---------------
hot metal temp. cooling water inlet
effec.hot sp.temp. effec.cold sp.temp.

FINAL WORK DIAGRAM:
(per cylinder, vol= cm^3, pressure= MPa)
angle _____ hot vol. ___ cold vol. ______ tot. vol. _ pressure ___ gas inv.

VOLUMES PER UNIT
HOT VOLUMES
= displacer end clearance, dead volume, cm^3
= heater tube dead volume, cm^3
+ ---------------
= total hot dead volume, cm^3
= hot active volume, cm^3
+ ---------------
= total max. hot volume, cm^3

COLD VOLUMES
= piston/displacer end clearance cold dead volume cm^3
= cooler tube dead volume cm^3
= cold dead volume outside cooler tubes, in connecting duct cm^3
+ -----------
= total cold dead volume, cm^3 (incl. connecting duct)
= cold active volume, cm^3
+ -----------
= total max. cold volume, cm^3

POWER CYLINDER VOLUMES (for gamma type only)
= piston end clearance, power cyl. dead volume, cm^3
= power cylinder active volume, cm^3

REGENERATOR VOLUMES
= regenerator inside dead volume, cm^3
= gap in hot cap dead volume, cm^3
+ -------------
= total regenerator dead volume, cm^3
HEAT TRANSFER (for whole engine)
= heat transfer area for cooler cm^2.
= heat transfer area of heater cm^2.

%
100-
90-
80-
70-
60-
50-
40-
30-
20-
10-
0-
Pressure working gas ( % of maximun pressure)
c c c c c c c c c c c c c
0 30 60 90 120 150 180 210 240 270 300 330 360
Angle degree
Hover mouse over a bar for detailed values.

%
100-
90-
80-
70-
60-
50-
40-
30-
20-
10-
0-
Volume, red= hot, green= total, blue= cold
( % of maximun total volume)
c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c
0 30 60 90 120 150 180 210 240 270 300 330 360
Angle degree

%
100-
90-
80-
70-
60-
50-
40-
30-
20-
10-
0-
Fraction of working gas mass on, red= hot side, purple= outside hot and cold side, blue= cold side.
( % of maximun total working gas mass.)
c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c c
0 30 60 90 120 150 180 210 240 270 300 330 360
Angle degree
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