Editing Boiling (section)

=== Flow boiling ===

"Flow boiling" occurs when the boiling fluid circulates, typically through pipes.<ref name="JamesHoldenFlowBoiling">{{cite journal | last1=Holden | first1=James B. | last2= Rowzee | first2= E. Ralph  | title=Adiabatic flow of boiling water through a horizontal pipe. | journal=Massachusetts Institute of Technology | publisher=Department of Chemical Engineering | year=1931}}</ref> Its movement can be powered by pumps, such as in power plants, or by density gradients, such as in a [[thermosiphon]] or a heat pipe. Flows in flow boiling are often characterised by a void fraction parameter, which indicates the fraction of the volume in the system that is vapor. One can use this fraction and the densities to calculate the [[vapor quality]], which refers to the mass fraction that is in the gas phase. Flow boiling can be very complex, with heavy influences of density, flow rates, and heat flux, as well as surface tension. The same system may have regions that are liquid, gas, and two-phase flow. Such two phase regimes can lead to some of the best heat transfer coefficients of any system.