MDM#

References#

Equation of State#

Monika Thol, Frithjof H. Dubberke, Elmar Baumhögger, Jadran Vrabec, and Roland Span. Speed of sound measurements and fundamental equations of state for octamethyltrisiloxane and decamethyltetrasiloxane. J. Chem. Eng. Data, 62(9):2633–2648, jul 2017. doi:10.1021/acs.jced.7b00092.

Surface Tension#

A. Mulero and I. Cachadiña. Recommended Correlations for the Surface Tension of Several Fluids Included in the REFPROP Program. J. Phys. Chem. Ref. Data, 43:023104–1:8, 2014. doi:10.1063/1.4878755.

Aliases#

Octamethyltrisiloxane, OCTAMETHYLTRISILOXANE

Molecular Structure#

MDM — 3D conformer (interactive: click and drag to rotate)

Fluid Information#

Parameter, Value

General

Molar mass [kg/mol]

0.23653146

CAS number

107-51-7

ASHRAE class

UNKNOWN

Formula

C8H24O2Si3

Acentric factor

0.5280658490542447

InChI

InChI=1S/C8H24O2Si3/c1-11(2,3)9-13(7,8)10-12(4,5)6/h1-8H3

InChIKey

CXQXSVUQTKDNFP-UHFFFAOYSA-N

SMILES

C[Si](C)(C)O[Si](C)(C)O[Si](C)(C)C

ChemSpider ID

23101

Limits

Maximum temperature [K]

575.0

Maximum pressure [Pa]

130000000.0

Triple point

Triple point temperature [K]

187.2

Triple point pressure [Pa]

0.0010820636776824135

Critical point

Critical point temperature [K]

565.3609009312738

Critical point density [kg/m3]

268.22371054291375

Critical point density [mol/m3]

1133.9874642591465

Critical point pressure [Pa]

1437537.7755043951

REFPROP Validation Data#

Note

This figure compares the results generated from CoolProp and those generated from REFPROP. They are all results obtained in the form \(Y(T,\rho)\), where \(Y\) is the parameter of interest and which for all EOS is a direct evaluation of the EOS

You can download the script that generated the following figure here: (link to script), right-click the link and then save as… or the equivalent in your browser. You can also download this figure as a PDF.

../../_images/MDM.png

Consistency Plots#

The following figure shows all the flash routines that are available for this fluid. A red + is a failure of the flash routine, a black dot is a success. Hopefully you will only see black dots. The red curve is the maximum temperature curve, and the blue curve is the melting line if one is available for the fluid.

In this figure, we start off with a state point given by T,P and then we calculate each of the other possible output pairs in turn, and then try to re-calculate T,P from the new input pair. If we don’t arrive back at the original T,P values, there is a problem in the flash routine in CoolProp. For more information on how these figures were generated, see CoolProp.Plots.ConsistencyPlots

Note

You can download the script that generated the following figure here: (link to script), right-click the link and then save as… or the equivalent in your browser. You can also download this figure as a PDF.

../../_images/MDM1.png

Flash consistency (HEOS): 49 inconsistent, 77 exceptions, 0 bad-phase across 11 input pair(s).

Download full failure list (CSV)

Failing state points (sample, up to 20 per pair/class)

Pair

Class

Region

P [Pa]

T [K]

In1

Val1

In2

Val2

Error

DmolarHmolar

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

DmolarHmolar

INCONSISTENT

1phase

0.00210164

188.3

Dmolar

3902.62

Hmolar

-102460

DmolarP

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

DmolarP

INCONSISTENT

1phase

0.00404149

188.3

Dmolar

3902.62

P

0.00403768

DmolarP

INCONSISTENT

1phase

0.0552684

208.131

Dmolar

3820.42

P

0.055294

DmolarP

INCONSISTENT

1phase

0.0552684

198.215

Dmolar

3861.43

P

0.0552756

DmolarP

INCONSISTENT

1phase

2.79499

237.877

Dmolar

3697.8

P

2.79499

DmolarP

INCONSISTENT

1phase

0.204383

188.3

Dmolar

3902.62

P

0.204379

DmolarP

INCONSISTENT

1phase

0.0552684

188.3

Dmolar

3902.62

P

0.0552646

DmolarP

INCONSISTENT

1phase

0.106282

198.215

Dmolar

3861.43

P

0.10629

DmolarP

INCONSISTENT

1phase

0.106282

208.131

Dmolar

3820.42

P

0.106309

DmolarP

INCONSISTENT

1phase

0.00210164

188.3

Dmolar

3902.62

P

0.00209824

DmolarP

INCONSISTENT

1phase

0.204383

208.131

Dmolar

3820.42

P

0.204409

DmolarP

INCONSISTENT

1phase

0.0287404

198.215

Dmolar

3861.43

P

0.028747

DmolarP

INCONSISTENT

1phase

0.0287404

188.3

Dmolar

3902.62

P

0.0287374

DmolarP

INCONSISTENT

1phase

0.00777187

188.3

Dmolar

3902.62

P

0.00776817

DmolarP

INCONSISTENT

1phase

0.0149455

198.215

Dmolar

3861.43

P

0.0149537

DmolarP

INCONSISTENT

1phase

0.0149455

188.3

Dmolar

3902.62

P

0.0149427

DmolarP

INCONSISTENT

1phase

0.106282

188.3

Dmolar

3902.62

P

0.106278

DmolarP

INCONSISTENT

1phase

0.204383

198.215

Dmolar

3861.43

P

0.20439

DmolarP

INCONSISTENT

1phase

0.393033

208.131

Dmolar

3820.42

P

0.393059

DmolarP

INCONSISTENT

1phase

0.393033

218.046

Dmolar

3779.51

P

0.393046

DmolarSmolar

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

DmolarSmolar

INCONSISTENT

1phase

0.00210164

188.3

Dmolar

3902.62

Smolar

-345.612

DmolarSmolar

INCONSISTENT

1phase

0.00404149

188.3

Dmolar

3902.62

Smolar

-345.612

DmolarT

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

DmolarT

INCONSISTENT

1phase

0.00210164

188.3

Dmolar

3902.62

T

188.3

DmolarT

INCONSISTENT

1phase

0.00404149

188.3

Dmolar

3902.62

T

188.3

DmolarUmolar

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

DmolarUmolar

INCONSISTENT

1phase

0.00210164

188.3

Dmolar

3902.62

Umolar

-102460

DmolarUmolar

INCONSISTENT

1phase

0.00404149

188.3

Dmolar

3902.62

Umolar

-102460

HmolarP

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

HmolarP

INCONSISTENT

1phase

0.00210164

188.3

Hmolar

-102460

P

0.00209824

HmolarSmolar

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

PSmolar

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

PSmolar

INCONSISTENT

1phase

0.00210164

188.3

P

0.00209824

Smolar

-345.612

PSmolar

INCONSISTENT

1phase

0.00404149

188.3

P

0.00403768

Smolar

-345.612

PT

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

PT

INCONSISTENT

1phase

0.00210164

188.3

P

0.00209824

T

188.3

PT

INCONSISTENT

1phase

0.00404149

188.3

P

0.00403768

T

188.3

PUmolar

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

PUmolar

INCONSISTENT

1phase

0.00210164

188.3

P

0.00209824

Umolar

-102460

PUmolar

INCONSISTENT

1phase

0.00404149

188.3

P

0.00403768

Umolar

-102460

SmolarT

EXCEPTION

1phase

2.57063e+06

565.085

P

2.57063e+06

T

565.085

p is not a valid number

SmolarT

INCONSISTENT

1phase

0.0552684

198.215

Smolar

-325.765

T

198.215

SmolarT

INCONSISTENT

1phase

0.0287404

198.215

Smolar

-325.765

T

198.215

SmolarT

INCONSISTENT

1phase

0.0149455

198.215

Smolar

-325.765

T

198.215

SmolarT

INCONSISTENT

1phase

0.0552684

208.131

Smolar

-306.845

T

208.131

SmolarT

INCONSISTENT

1phase

0.00210164

575

Smolar

370.134

T

575

SmolarT

INCONSISTENT

1phase

0.00109288

575

Smolar

375.57

T

575

SmolarT

INCONSISTENT

1phase

0.393033

188.3

Smolar

-345.612

T

188.3

SmolarT

INCONSISTENT

1phase

0.75581

188.3

Smolar

-345.612

T

188.3

SmolarT

INCONSISTENT

1phase

0.0287404

188.3

Smolar

-345.612

T

188.3

SmolarT

INCONSISTENT

1phase

0.204383

188.3

Smolar

-345.612

T

188.3

SmolarT

INCONSISTENT

1phase

0.106282

188.3

Smolar

-345.612

T

188.3

SmolarT

INCONSISTENT

1phase

0.0552684

188.3

Smolar

-345.612

T

188.3

SmolarT

INCONSISTENT

1phase

0.0149455

188.3

Smolar

-345.612

T

188.3

SmolarT

INCONSISTENT

1phase

0.00777187

188.3

Smolar

-345.612

T

188.3

SmolarT

INCONSISTENT

1phase

0.00404149

188.3

Smolar

-345.612

T

188.3

SmolarT

INCONSISTENT

1phase

0.00210164

188.3

Smolar

-345.612

T

188.3

Superancillary Plots#

The following figure shows the accuracy of the superancillary functions relative to extended precision calculations carried out in C++ with the teqp library. The results of the iterative calculations with REFPROP and CoolProp are also shown.

Note

You can download the script that generated the following figure here: (link to script), right-click the link and then save as… or the equivalent in your browser. You can also download this figure as a PDF.

../../_images/MDM2.png