Nested subcritical flows within supercritical systems
Abstract
In supercritical systems the design inlet and outlet pressures are maintained above the thermaodynamic critical pressure P sub C. Designers rely on this simple rule of thumb to circumvent problems associated with a subcritical pressure regime nested within the supercritical pressure system along with the uncertainties in heat transfer, fluid mechanics, and thermophysical property variations. The simple rule of thumb is adequate in many low-power designs but is inadequate for high-performance turbomachines and linear systems, where nested two-phase regions can exist. Examples for a free-jet expansion with backpressure greater than P sub C and a rotor (bearing) with ambient pressure greater than P sub C illustrate the existence of subcritical pressure regimes nested within supercritical systems.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- March 1985
- Bibcode:
- 1985STIN...8521574H
- Keywords:
-
- Fluid Mechanics;
- Heat Transfer;
- Pressure Gradients;
- Supercritical Flow;
- Thermophysical Properties;
- Cryogenics;
- Inlet Pressure;
- Linear Systems;
- Stagnation Pressure;
- Turbomachinery;
- Two Phase Flow;
- Fluid Mechanics and Heat Transfer