A STUDY OF SYSTEM-INDUCED INSTABILITIES IN FORCED-CONVECTION FLOWS WITH SUBCOOLED BOILING.
MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF MECHANICAL ENGINEERING
Pagination or Media Count:
A combined analytical and experimental program was carried out to investigate the problem of hydrodynamic stability of forced-convection flows with boiling. Two types of instability were recognized The first, a nonrecurring excursive instability, and the second, an oscillatory instability in which the operating point varies in a sustained, repetitive way around the original condition. The excursive behavior was predicted on the basis of a comparison of the slopes of the pressure drop vs. flow rate curve of the heated section and the external system. The oscillatory instability was investigated analytically through the use of a linearized, lumped parameter model in which steady-state measurements of the pressure drop were assumed to be valid in characterizing the transient characteristics of the heated section. For cases in which the energy storage mechanism was a compressible volume either upstream of, or within, the heated section, a critical slope of the pressure drop vs. flow rate curve in the heated section could be computed, as well as an associated frequency.