Two‐phase flow, thermal management systems are currently being considered as an alternative to conventional, single phase systems for future space missions because of their potential to reduce overall system mass, size, and pumping power requirements. Knowledge of flow regime transitons, heat transfer characteristics, and pressure drop correlations is necessary to design and develop two‐phase systems. This work is concerned with microgravity, two‐phase flow pressure drop experiments.
The data are those of a recent experiment (Hill et al. 1990) funded by the U.S. Air Force and conducted by Foster‐Miller in conjuction with Texas A&M University. A boiling and condensing experiment was built in which R‐12 was used as the working fluid. A Forster‐Miller two phase pump was used to circulate a freon mixture and allow separate measurements of the vapor and liquid flow streams. The experimental package was flown five times aboard the NASA KC‐135 aircraft which simulates zero‐g conditions by its parabolic flight trajectory. Test conditions included stratified and annual flow regimes in 1‐g which became bubbley, slug or annular flow regimes in 0‐g. A portion of this work is the analysis of adiabatic flow regimes. The superfical velocities of liquid and vapor have been obtained from the measured flow rates and are presented along with the observed flow regimes.
