Calculators › ThermoWorks
PHYSICAL PROPERTIES
ThermoWorks
Build fluid mixtures and calculate thermodynamic and transport properties.
Builds a fluid mixture from a catalogue of 34 components and calculates its phase split and its thermodynamic and transport properties at a given temperature and pressure, or a pure fluid at saturation with a given vapour quality.
Prices
| Runs | Price |
|---|---|
| Every run | 1 credit |
- A run that fails because of its inputs, doesn't converge or runs out of time is free.
- Cancelling a run is free, before or after it starts.
- A fault on our side is never charged: the run is tried again automatically.
A credit costs 8p to 10p, depending on the pack. Credits don't expire. Packs and prices
Inputs and results
You enter
- Up to 200 component rows, by mole or by mass
- Temperature and pressure, in metric, SI or US units
- For a pure fluid at saturation, its vapour quality
You get
- The phase (liquid, vapour or two-phase) and the vapour fraction
- Liquid and vapour compositions and molecular weights
- Liquid and vapour densities and viscosities, surface tension and the compressibility factor
- Ideal-gas heat capacity and its ratio γ
- Bubble and dew temperatures
- Every correlation used outside its source temperature range
Example: Stream properties
VAPOURDry air (nitrogen, oxygen, argon and carbon dioxide) at 25 °C and 1.01325 bar absolute.
The starting case every new ThermoWorks case opens on, run by the engine on our servers and stored (engine 1.0.0 · data 1.0.0). Nothing is calculated in your browser, here or in the calculator. Exports and the other tools of a run need an account.
Phase properties
| Property / units | Liquid | Vapour |
|---|---|---|
| Molecular weight kg/kmol | — | 28.96514 |
| Density kg/m³ | — | 1.184575 |
| Dynamic viscosity cP | — | 0.01736315 |
| Surface tension mN/m | — | — |
| Compressibility Z — | — | 0.9994492 |
| Ideal-gas Cp kJ/(kg·K) | — | 1.013352 |
| Heat-capacity ratio γ (estimate) — | — | 1.395527 |
Phase quantities
| Property / units | Liquid | Vapour |
|---|---|---|
| Mass flow kg/h | 0 | 1,000 |
| Molar flow kmol/h | 0 | 34.52426 |
| Actual volume flow m³/h | — | 844.1847 |
Composition & balance
| Component | Feed mol% | Feed wt% | Liquid mol% | Vapour mol% |
|---|---|---|---|---|
| NITROGEN | 78.084 | 75.51723 | — | 78.084 |
| OXYGEN | 20.946 | 23.13992 | — | 20.946 |
| ARGON | 0.934 | 1.28815 | — | 0.934 |
| CARBON DIOXIDE | 0.036 | 0.05469886 | — | 0.036 |
Maximum molar component balance residual: 0.00e+0. Liquid density method: not applicable.
Bubble / dew estimates
At 1.01325 bara: bubble -194.1657 C; dew -163.8561 C. A dash means no root was found within 40–1000 K. These are estimates, especially for supercritical mixtures.
4 component/property correlations are outside their temperature ranges. Results include extrapolation; inspect the coverage list.
Correlation coverage
NITROGEN: psat 63.15–123.15 K
OXYGEN: psat 54.36–154.36 K
ARGON: psat 83.8–143.8 K
CARBON DIOXIDE: psat 216.59–296.59 K
Methods
- Phase split: K-values from a vapour-pressure correlation (a Wilson-type expression above the critical temperature) and a Rachford–Rice flash
- Vapour: the Peng–Robinson equation of state without binary interaction parameters; Wilke's mixing rule for viscosity
- Liquid: additive specific volumes from DIPPR-style densities (Peng–Robinson where a correlation is missing), logarithmic viscosity mixing and mole-weighted surface tension
- Bubble and dew temperatures: screening estimates from the same K-values, between 40 and 1000 K
How every calculator is tested: Methods and validation.
Limits
- No activity coefficients, binary interaction parameters or solids
- Not calculated: thermal conductivity, liquid heat capacity and enthalpy
- γ is estimated as Cp/(Cp − R/Z), not a real-gas acoustic derivative
- Results outside a correlation's source range are extrapolated, and listed for review
Results are screening estimates from the methods described. A competent engineer must check them before relying on them in design, safety or operating decisions.
How it is checked
- Parity with the original
- The engine is a port of the original standalone calculator, and reproduces it on 882 generated cases: every quantity within 10⁻¹² relative.
- Validation against reference data
- Saturation properties at 1.01325 bar against NIST reference data. 13 cases, 4 of them documented limits of the model.
Single-phase densities and viscosities against NIST reference data. 8 cases.