Prediction and Attainment Capability for Quasi-Steady Internal Condensing Flows: An Integrated Experimental/Computational Approach

建议编号：CTS-0086988主要调查者：A.纳瑞恩摘要管内稳定或准稳定的环状或分层内部冷凝流动(对于任何给定的入口压力、质量流量和冷凝面温度分布)的实现取决于凝汽器段的散热率和出口压力条件之间的兼容性，或者等效地，出口蒸汽流量分数。对于某些出口条件，实现了准定常的波状界面流动，而在其他条件下，由可压缩性引起的显著振荡将持续存在。这些悬而未决的问题将借助电子流动控制技术进行实验研究，该技术有助于确定不同出口条件下可实现准稳定流动的条件范围。该实验还将对内径为6.35 mm、长0.8m的管内环状气膜冷凝进行新的观测和测量。管道以及随后的通道可以从垂直向下到水平配置运行。我们还提出了用荧光技术测量FC-72等掺杂电致冷剂沸腾和冷凝流动的时变冷凝膜厚度，从这些测量中可以得到平均值和波状结构。不同的努力将拟议的实验研究的结果与计算模拟和环路热管等应用相联系。

Proposal Number: CTS-0086988Principal Investigator: A. NarainAbstractAchievement of steady or quasi-steady annular or stratified internal condensing flows in pipe (for any given inlet pressure, mass flow rate, and condensing surface temperature distribution) is dependent on compatibility between the condenser-section heat removal rate and exit pressure condition, or, equivalently, exit vapor flow rate fraction. For certain exit conditions, quasi-steady wavy-interface flows are realized and, for other conditions, significant compressibility-induced oscillations will persist. These unresolved issues will be experimentally investigated with the help of electronic flow control techniques which assist in identifying the range of conditions for which quasi-steady flows are achievable for different exit conditions. The experiment will also allow for novel observations and measurements for annular film condensation in 6.35 mm inner diameter pipe of 0.8 m length. The pipe, and subsequently channel, may operate from vertically downward to horizontal configurations. We also propose to measure time-varying condensate film thickness by fluorescence technique applicable to boiling and condensing flows of doped di-electric refrigerants such as FC-72, etc. From these measurements, mean and wave-structure may be found. Separate efforts relate the results of the proposed experimental research to computational simulations and applications such as Looped Heat Pipes, etc.