Pressure drop prediction models Garimella et al. (2005) Considered parameters Single-phase pressure gradients Martinelli parameter Surface tension parameter Fluid and geometric properties Heat and Mass Transfer Laboratory

Pressure drop prediction models Garimella et al. (2005) Void fraction is calculated using the Baroczy (1965) correlation: Liquid and vapor Re values are given by: Heat and Mass Transfer Laboratory

Pressure drop prediction models Garimella et al. (2005) Liquid and vapor friction factors: Therefore, the single-phase pressure gradients are given and the Martinelli parameter is calculated: Heat and Mass Transfer Laboratory 3

Pressure drop prediction models Garimella et al. (2005) Liquid superficial velocity is given by: This velocity is used to evaluate the surface tension parameter: Heat and Mass Transfer Laboratory 4

Pressure drop prediction models Garimella et al. (2005) Interfacial friction factor: Laminar region: Turbulent region (Blasius): Heat and Mass Transfer Laboratory 5

Pressure drop prediction models Garimella et al. (2005) The pressure gradient is determined as follows: Heat and Mass Transfer Laboratory 6

Heat transfer prediction models Bandhauer et al. (2005) Considered parameters Pressure drop Dimensionless film thickness Turbulent dimensionless temperature Pr Fluid and geometric properties Heat and Mass Transfer Laboratory

Heat transfer prediction models Bandhauer et al. (2005) Interfacial shear stress: Friction velocity is now calculated: Heat and Mass Transfer Laboratory 8

Heat transfer prediction models Bandhauer et al. (2005) Film thickness is directly calculated from void fraction: This thickness is used to obtain the dimensionless film thickness: Heat and Mass Transfer Laboratory 9

Heat transfer prediction models Bandhauer et al. (2005) Turbulent dimensionless temperature is given by: Therefore, the heat transfer coefficient is: Heat and Mass Transfer Laboratory 10