Accident Scenario:Loss-of-Coolant Accident (LOCA) leak ! 9
Accident Scenario:Reflux Condenser Mode after a LOCA steam 0,7m water detail view
Severe Accident of the TMI-reactor in Harrisburg 1979 Upper Grid Damage Cavity Fuel Assembly Remnants Baffle Plate Loose Debris Melt-Through 0:00: =261 OOE 月alocation Resolidified Pathways Molton Pocl =330 Fuel Rod Stubs Resolldifled Debris Inside Upper CSA ©4和 Resolidified Debris Experiment Inside Lower CSA Loose Debris -61 Monolithic Layer of -131 Resolidified Debris -78
*两相流的复杂性 除单相流(Single-Phase Flow)所包含的复杂性 （如 湍流等)以外，因相间相互作用（相间质量、动量、能量传输)以 及相界面变形（表面张力、相间相互作用力)等因素，所以两相 流将更复杂！ 单相流中，有两种主要的流动工况：层流、湍流； 两相流中，不仅每一相中分别出现这两种流动形态 各相界面结构与拓扑分布(Interface Structures and Topographical Distribution of Phases)还会导致出现很多复杂的流型与流动工况 Flow Pattern,Flow Regime)o
例1：弥散型与非弥散型两相流 Disperse Two-Phase Flows (=Dispersions) one phase continuous the other:discontinuous (disperse) droplet flow(spray) bubble flow solid particle flow liquid disperse gas disperse solid disperse gas continous liquid continous gas (or liquid)continous No dispersion: churn flow (e.g.breaking wave) granular flow stratified flow porous medium