Pressure-drop and density-wave instability thresholds in boiling channels

Conference · Thu Jan 01 04:00:00 EST 1987

OSTI ID:5634685

Gurgenci, H; Yildirim, T; Kakac, S; Veziroglu, T N

In this study, a criterion for linearized stability with respect to both the pressure-drop and the density-wave oscillations is developed for a single-channel upflow boiling system operating between constant pressures with upstream compressibility introduced through a surge tank. Two different two-phase flow models, namely a constant-property homogeneous flow model a variable-property drift-flux model, have been employed. The conservation equations for both models and the equations of surge tank dynamics are first linearized for small perturbation and the stability of the resulting set of equations for each model are examined by use of Nyquist plots. As a measure of the relative instability of the system, the amounts of the inlet throttling necessary to stabilize the system at particular operating points have been calculated. The results are compared with experimental findings. Comparisons show that the drift-flux formulation offers a simple and reliable way of determining the instability thresholds.

• OSTI ID: 5634685
• Report Number(s): CONF-861211-
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420400* -- Engineering-- Heat Transfer & Fluid Flow
BOILING
COMPRESSIBILITY
CONTAINERS
DENSITY
DIAGRAMS
FLOW MODELS
FLUID FLOW
FLUID MECHANICS
HEAT FLUX
HYDRODYNAMICS
INSTABILITY
MATHEMATICAL MODELS
MECHANICAL PROPERTIES
MECHANICS
NYQUIST DIAGRAMS
PHASE TRANSFORMATIONS
PHYSICAL PROPERTIES
PRESSURE DROP
TANKS
THERMODYNAMICS
TWO-PHASE FLOW