Two phase flow instabilities: pressure-drop type oscillation thresholds

Thesis/Dissertation · Tue Jan 01 04:00:00 EST 1985

OSTI ID:5971606

Mentes, A

Experimental and theoretical work have been carried out to find out the effects of heat transfer augmentation on two phase flow instabilities in a single channel system. An open loop vertical, forced convection up-flow boiling flow experimental setup is built for this purpose and Freon-11 is used as the test fluid. The effect of mass flow rate, heat input, and inlet subcooling on the system behavior is studied. Six different heater surfaces are tested at six different heat inputs with constant inlet temperature and six different inlet temperatures with constant heat input. Mass flow rate is varied over a wide range for both cases; heat input and the inlet temperature of the test fluid are varied from 0 to 3 x 10/sup 4/ W/m/sup 2/ and from -7.5 to 38/sup 0/C, respectively. The steady state pressure drop versus mass flow rate curves, stability boundary maps, along with the curves of additional inlet pressure drop required to stabilize the system during the oscillations were developed and tables were generated using the experimental data. A one-dimensional, homogeneous equilibrium flow model is used in theoretical analysis, and conservation equations with the constitutive relations are solved by finite differences under the specified boundary conditions to obtain the steady-state characteristics.

• Research Organization: Miami Univ., Coral Gables, FL (USA)
• OSTI ID: 5971606
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
CONVECTION
ENERGY TRANSFER
FLOW MODELS
FLUID FLOW
FORCED CONVECTION
HEAT TRANSFER
INSTABILITY
MASS TRANSFER
MATHEMATICAL MODELS
OSCILLATIONS
PRESSURE DROP
TWO-PHASE FLOW