该项目的目的是在大约大气压下，在均匀热流和试验流体流速范围内，对水平管蒸发器中的两相单组分流动进行可视化和定量研究，研究条件为过冷和整体沸腾。一个强制对流试验回路，包括一个12英尺长的水平试验段，该试验段由五个，使用“氟利昂-113”，在入口过冷度（至46F）、热流（至8000 BTU/hr-ft2）和流速（至1392 lbm-hr）范围内，制造并运行内径为430”的透明电阻加热膜涂层玻璃管“作为试验流体。除了测量所有入口条件以及温度、压力和热流分布外，还拍摄了每一次最终类型运行的高速照片，以便对数据进行准确解释。实验结果如下（1）在过冷沸腾区壁上产生的气泡不会坍塌，但在向下游移动时会继续增长； （2） 在大部分流体饱和后不久，流体就变成环状；（3） 大部分流体在整体沸腾区域过热几度；（4）一旦形成环形流，离散点的成核对传热没有贡献。根据现有关联式对数据进行的检查表明，对于过冷和低质量沸腾区域，实际空隙率必须包含在任何关联式中，其中有机流体的质量几乎为零，对于空隙率几乎恒定的环形流区域，包含实际质量影响的关联式将是最好的。在所研究的变量范围内，过冷沸腾区初始核沸点的位置对局部传热系数有显著影响。然而，这种影响是由于流体力学的显著变化，而不是核沸腾传热贡献的变化。 单位:I-P

The object of this program was to conduct, at approximately atmospheric pressure, a visual and quantitative study of two-phase one-component flow in a horizontal tube evaporator under conditions of subcooled and bulk boiling over a range of uniform heat fluxes and test fluid flow rates.A forced convection test loop including a horizontal twelve foot long test section comprised of five,.430" I.D., transparent electric resistance heating film coated glass tubes was constructed and operated over a range of inlet subcoolings (to 46F), heat fluxes (to 8000 BTU/hr-ft2) and flow rates (to 1392 lbm-hr) using "Freon-113" as the test fluid.In addition to the measurement of all inlet conditions and the temperature, pressure, and heat flux distributions, high speed photographs were taken of each final type run in order to permit an accurate interpretation of the data.The experimental results are (1) bubbles originating at the wall in the subcooled boiling region do not collapse but continue to grow as they move downstream; (2) the flow becomes annular soon after the bulk of the fluid becomes saturated; (3) the bulk of the fluid is superheated several degrees in the bulk boiling region; and (4) nucleation at discrete points does not contribute to the heat transfer once an annular flow is established.Examination of the data in the light of existing correlations indicates that the actual void fraction must be included in any correlation for the subcooled and low quality boiling region where the quality is nearly zero for organic fluids and that a correlation including the effect of an actual mass quality will be the best for the annular flow region where the void fraction is nearly constant.For the range of variables studied, location of the initial nucleate boiling point in the subcooled boiling region has a pronounced effect on the local heat transfer coefficient. However, the effect is due to a significant change in the fluid mechanics rather than a change in the nucleate boiling heat transfer contribution.Units: I-P