Condensation in mini- and microchannels Hussein Dhanani Sebastian Schmidt Christian Metzger Assistent: Marcel Christians-Lupi I present to you Stephano Nebuloni, and I’m Anthony Servonet, and we’ll speak about the “microchannel flow boiling correlations and 3-zones model”. On this project, we also compared these model to recent published results. XX December 2007 Heat and Mass Transfer Laboratory

Heat and Mass Transfer Laboratory Structure Introduction to condensation in microchannels Pressure drop Prediction models Friedel (1979;1980) Chen (2001) Wilson (2003) Cavallini (2001;2002) Garimella (2005) Comparison with experimental data Conclusion Heat and Mass Transfer Laboratory

Heat and Mass Transfer Laboratory Structure Heat transfer Prediction models Shah (1979) Dobson & Chato (1998) Cavallini (2002) Bandhauer (2005) Comparison with experimental data Conclusions Questions Heat and Mass Transfer Laboratory

Heat and Mass Transfer Laboratory Pressure drop Common parameters used by several correlations Liquid Reynolds number Vapor Reynolds number Liquid-only Reynolds number Vapor-only Reynolds number Heat and Mass Transfer Laboratory

Heat and Mass Transfer Laboratory Pressure drop Common parameters used by several correlations Single-phase friction factor (smooth tube) Single-phase pressure gradients Heat and Mass Transfer Laboratory

Pressure drop prediction models Friedel (1979;1980) Considered Parameters Liquid only single-phase pressure gradient Liquid only and vapor only friction factor Fluid and geometric properties Heat and Mass Transfer Laboratory

Pressure drop prediction models Friedel (1979;1980) Heat and Mass Transfer Laboratory

Pressure drop prediction models Chen (2001) Modification of the Friedel correlation by adding two-phase multiplier Considered Parameters Two-phase pressure gradient by Friedl We, Bo, Re_v, Re_lo Heat and Mass Transfer Laboratory

Pressure drop prediction models Chen (2001) Heat and Mass Transfer Laboratory

Pressure drop prediction models Cavallini (2002) Modification of the Friedel correlaction by changing several parameter definitions Considered Parameters Liquid only single-phase pressure gradient Liquid only and vapor only friction factor Fluid and geometric properties Heat and Mass Transfer Laboratory

Pressure drop prediction models Cavallini (2002) Friedel Heat and Mass Transfer Laboratory

Pressure drop prediction models Cavallini (2002) Heat and Mass Transfer Laboratory

Heat transfer prediction models Cavallini* (2002) Considered Parameters Pressure drop Dimensionless film thickness Dimensionless temperature Re, Pr Fluid and geometric properties * Applicable for annular regime only Heat and Mass Transfer Laboratory

Heat transfer prediction models Calculation of the shear stress Dimensionless film thickness Heat and Mass Transfer Laboratory

Heat transfer prediction models Dimensionless temperature Heat transfer coefficient Heat and Mass Transfer Laboratory