An effective method for modeling 1D two-phase two-fluid six-equation model with automatic differentiation approach

Void fraction thermo-kinematics for subcooled flow boiling

“…Given the complexity and computing power of the PDE system posed, i.e., it is able to calculate not only the steady but also transient cases, to follow the void fraction as well as pressure drop through a large number of cells along the duct, etc., the number of variables and parameters of the model logically soars. Niu et al 17 validate their model both in the subcooled and saturated flow boiling conditions. For the subcooled experiments, they find good agreement between their model and Bartolomei experimental data.…”

“…Currently, it is thought that the ability to calculate the NVG point is the most important element in predicting the axial void fraction profile although it is still ongoing in discussion. 16 Figure 7 can be compared with the results of a very recent work of Niu et al, 17 in which a new model for the 1D transient two-phase two-fluid six-equation model with automatic differentiation approach is presented. In the two-fluid model, two sets of conservation equations describe the balance of mass, momentum, and energy for each phase, as well as the balance equations at the phase interfaces with a large amount of realistic closure correlations.…”