1. Convective boiling

1.1 Phase change flows: specific quantities

When a liquid flows by forced convection close to a heated wall, and the conditions imposed enable a liquid/vapor phase change, this is called convective boiling. The distribution of the phases differs significantly according to the degree of fractionation of the two phases. Various quantities can be used to specify the proportions of each phase and the characteristics of the flow. These are presented in this section, together with the relationships between them, based on the co-current flow of the two phases.

• Void fraction or void ratio ε

  For a tube of cross-section A, where the steam occupies a cross-section A _v and...