Доступ предоставлен для: Guest

ISSN Online: 2377-424X

ISBN Print: 0-85295-345-3

International Heat Transfer Conference 10
August, 14-18, 1994, Brighton, UK

A MIXED NATURAL/FORCED CONVECTION NUCLEATE BOILING HEAT TRANSFER CRITERIA

Get access (open in a dialog) DOI: 10.1615/IHTC10.1320
pages 479-484

Аннотация

In order to sustain boiling on a heating surface in microgravity, it is necessary to have some mechanism to supplant buoyancy in removing the vapor from the heating surface. This can be provided by the drag forces acting on vapor bubbles in forced convection boiling. However, the conditions necessary to produce this removal have not been established. In single phase mixed convection heat transfer both buoyancy and imposed bulk liquid flow provide the mechanisms for fluid motion, where the relative significance of these is characterized by the Richardson number. A similarly defined "two-phase Richardson number" is developed here. Results from low velocity nucleate flow boiling experiments are presented for various flat heater surface orientations relative to earth gravity, and support the concept of the two-phase Richardson number. The experimental results are used to delimit the buoyancy dominant and inertial dominant regimes.