Calculators › PhaseWorks
TWO-PHASE FLOW
PhaseWorks
Explore mixture properties, hydraulic losses and flow regimes.
Calculates the frictional pressure loss of a two-phase (or single-phase) stream in a horizontal line with fittings and valves, and places it on the Baker flow-regime map.
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
- The stream: a ThermoWorks mixture, a pure fluid at saturation, or the workbook's saved snapshot; measured phase properties can replace calculated ones
- Flow rate, temperature and pressure
- Bore, length, roughness, fittings, valves (Cv) and extra resistance
You get
- Two-phase pressure gradient, total loss and equivalent length
- Each phase's own loss and the two-phase multiplier
- The stream's point on the Baker map and its flow regime
Example: Two-phase flow
TWO PHASEThe workbook's line with the same light-hydrocarbon mixture: 6,000 kg/h at 170 K and 11.01325 bar absolute through 128 m of 102.26 mm bore pipe.
The starting case every new PhaseWorks 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.
Baker flow map
X 7.248 / Y 31,882Operating point and regime from the calculation, on Baker’s axes; the regions’ boundaries are not drawn.
Live property transfer · 6,000 kg/h at -103.15 °C, 11.01325 bar absolute. Liquid density: PR liquid-root fallback.
Mixture & phase properties
| Property | Liquid | Vapour |
|---|---|---|
| Density · kg/m³ | 616.381302234 | 14.903500138 |
| Viscosity · cP | 0.129345725 | 0.007162785 |
| Phase mass flow · kg/h | 2,458.591259232 | 3,541.408740768 |
| Molecular weight · g/mol | 29.747791694 | 16.575448835 |
| Surface tension · mN/m | 13.502650558 | — |
| Compressibility Z | — | 0.866581498 |
| HEM density · kg/m³ | 24.833268 | |
Hydraulic detail
| Quantity | Result |
|---|---|
| Liquid superficial velocity · m/s | 0.13491 |
| Gas superficial velocity · m/s | 8.03675 |
| Liquid / gas Reynolds number | 65,733 / 1.710e+6 |
| Liquid / gas Darcy factor | 0.021545 / 0.016925 |
| Fully turbulent factor fT | 0.016616 |
| Fitting K · inventory + other fitting K | 4.253574 |
| Combined Cv equivalent K | 123.706999 |
| Equivalent pipe length · m | 856.3058 |
| Actual straight length · m | 128 |
Phase composition & balance
| Component | z · feed | x · liquid | y · vapour |
|---|---|---|---|
| METHANE | 0.82 | 0.454479 | 0.961395 |
| ETHANE | 0.07 | 0.22805 | 0.008862 |
| PROPANE | 0.035 | 0.124834 | 0.000249 |
| n-BUTANE | 0.015 | 0.053762 | 0.000006 |
| ISOBUTANE | 0.008 | 0.028662 | 0.000007 |
| n-PENTANE | 0.005 | 0.017925 | 0 |
| NITROGEN | 0.02 | 0.0032 | 0.026499 |
| CARBON DIOXIDE | 0.027 | 0.089087 | 0.002983 |
Vapour mole fraction β = 0.721069. Maximum component mole-balance residual: 6.94e-18.
Calculation scope & data coverage
CARBON DIOXIDE: T is below its pure-component freezing point (216.58 K); no solids model.
Pure liquid density is undefined for at least one dissolved supercritical component. Entire liquid density uses Peng–Robinson (kij = 0), rather than dropping its mass.
Liquid-density PR fallback has one real physical root; liquid character is not independently confirmed.
12 component/property correlations are outside their temperature ranges. Results include extrapolation; inspect the coverage list.
Pressure loss exceeds 10% of inlet absolute pressure; constant-property hydraulics needs a segmented pressure-dependent check.
Out-of-range correlations at 170 K
PROPANE: muL 240–418 K
n-BUTANE: muL 180–425 K
ISOBUTANE: muL 190–408 K
NITROGEN: psat 63.15–123.15 K
NITROGEN: density 63.15–126.1 K
NITROGEN: muL 63–125 K
NITROGEN: sigma 63.15–126.1 K
CARBON DIOXIDE: psat 216.59–296.59 K
CARBON DIOXIDE: density 216.58–304.19 K
CARBON DIOXIDE: muL 219–304 K
CARBON DIOXIDE: sigma 216.58–304.19 K
CARBON DIOXIDE: muG 195–1500 K
Methods
- Each phase taken to flow alone through the line, with friction and fittings from Crane's Technical Paper 410
- The two-phase loss from a Lockhart–Martinelli-type liquid multiplier (the workbook's fit)
- The flow regime from Baker's map (Oil and Gas Journal, 1954)
How every calculator is tested: Methods and validation.
Limits
- Horizontal lines only: no elevation, acceleration or heat transfer
- No slip or holdup: the regime is a classification and does not change the loss
- Properties are constant along the line
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 820 generated cases: every quantity within 10⁻¹² relative.
- Validation against reference data
- No published reference cases yet.
- The original's own checks
- Reproduces the workbook's saved case: the Baker point, gradient, loss and regime.