ISSN Online: 2377-424X
ISBN Print: 0-89116-559-2
International Heat Transfer Conference 8
TWO-PHASE FLOWS AND HEAT TRANSFER WITHIN SYSTEMS WITH AMBIENT PRESSURE ABOVE THE THERMODYNAMIC CRITICAL PRESSURE
Аннотация
In systems where the design inlet and outlet pressures Pamb are maintained above the thermodynamic critical pressure Pc, it is often assumed that heat and mass transfer are governed by single-phase relations and that two-phase flows cannot occur. This simple rule of thumb is adequate in many low-power designs but is inadequate for high-performance turbomachines, boilers, and other systems where two-phase regions can exist even though Pamb > Pc. Heat and mass transfer and rotordynarmc-f1uid-mechaniÑ restoring forces depend on momentum differences; and those for a two-phase zone can differ significantly from those for a single-phase zone. By using a laminar, variable-property bearing code and a rotating boiler code, pressure and temperature surfaces were determined that illustrate nesting of a two-phase region within a supercritical pressure region. The method of corresponding states is applied to bearings with reasonable rapport (within 5 percent for an oxygen/nitrogen example).