This research is focused on the experimental analysis and numerical simulation of adiabatic developingtwo-phase refrigerant flow in manifolds including the inlet tube after the expansion device.The two-phase flow development in the tube after the expansion valve significantly affects distribution inthe manifold. Visualized flow structure is divided into three regions. The transitions among these regions are basedon the phase separation status. Relationships between the lengths of those regions and flow characteristics aredeveloped. The liquid phase is assumed to be continuous phase at high quality conditions so that the Eulerian modelof Eulerian-Eulerian approach is chosen for the numerical simulation using FLUENT 6. Better prediction isachieved for high inlet qualities.Two-phase flow regimes in the manifold are mapped for the first time. Indicators of distribution uniformityare plotted in the maps. The maps are presented in two forms: non-dimensional Froude number coordinates andmass flux-quality coordinates. Effect of the two-phase flow in the inlet tube (after the expansion valve) ondistribution in the manifold is explored. Eulerian model in FLUENT 6 is the most appropriate for the conditionsstudied in the manifold. Simulation results for the same geometry of the manifold and the same operating conditionsas used in experiments demonstrate very good prediction of flow field and reasonable prediction of liquiddistribution among branches.Experiments were performed using R134a in a facility designed for visualization (PDPA, photo) and twophaseflow distribution measurements for various inlet tube and flow characteristics. For most experiments, atransparent manifold in simplified geometry was used. Further experimental analysis is done for a manifold of a realplate evaporator. Atomization nozzles are first time applied as the expansion devices at the inlet of the manifold inorder to generate mist homogenous flow, which in this study is proven to contribute to uniform distribution.
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