25.12.2012 Views

Aspen Physical Property System - Physical Property Models

Aspen Physical Property System - Physical Property Models

Aspen Physical Property System - Physical Property Models

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Rackett<br />

The Rackett equation is:<br />

Where:<br />

Tr = T / Tci<br />

Note: Reduced temperature Tr is always calculated using absolute<br />

temperature units.<br />

Note: Above Tr=0.99 an extrapolation method is used to smooth the<br />

transition to constant molar volume equal to the critical volume.<br />

Parameter<br />

Name/<br />

Element<br />

2 Thermodynamic <strong>Property</strong> <strong>Models</strong> 205<br />

Symbol Default MDS Lower<br />

Limit<br />

Upper<br />

Limit<br />

Units<br />

TC T ci — — 5.0 2000.0 TEMPERATURE<br />

PC p ci — — 10 5<br />

RKTZRA Z i *,RA<br />

NIST TDE Rackett Parameters<br />

10 8<br />

ZC x 0.1 1.0 —<br />

PRESSURE<br />

This equation can be used when the parameter DNLRACK is available.<br />

Linear extrapolation of Vi *,l versus T occurs outside of temperature bounds.<br />

Parameter<br />

Name/<br />

Element<br />

Symbol Default MDS Lower<br />

Limit<br />

Upper<br />

Limit<br />

DNLRACK/1 Z c — x — — —<br />

DNLRACK/2 n 2/7 x — — —<br />

Units<br />

DNLRACK/3 T ci — x — — TEMPERATURE<br />

DNLRACK/4 p ci 0 x — — PRESSURE<br />

DNLRACK/5 T lower 0 x — — TEMPERATURE<br />

DNLRACK/6 T upper 1000 x — — TEMPERATURE<br />

NIST COSTALD Parameters<br />

This equation can be used when the parameter DNLCOSTD is available.

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!