(two_phase_pressure_drop)=
# Two-phase pressure drop

```{admonition} Summary
* **Subject:** Two-phase pressure drops
* **Main conclusion** Chisholm's two-phase multiplier $\phi_{L}^{2} = 1 + \frac{C}{X} + \frac{1}{X^{2}}$
* **Key idea** Two-phase multiplier extends single-phase modeling to two-phase flow situations.
* **References** 
    - {cite:t}`Lockhart1949`: The first of separate flow model
    - {cite:t}`Chisholm1967-zs`: derivation of {cite:p}`Lockhart1949`
    - {cite:t}`Chisholm1983-wy`: consistent approach is utilized to establish 1D modeling of a wide variety of two-phase problems. 
```

Pressure drop is of fundamental importnce in fluid engineering. The same applies to two-phase flows. Fundamental treatments of two-phase pressure drop will be discussed in the following. 

```{toctree} 
:maxdepth: 1

two_phase_pressure_drop/pd_global_balance
two_phase_pressure_drop/pd_homogeneous
two_phase_pressure_drop/pd_lockhart
```