Effect of thermodynamic disequilibrium on critical liquid-vapor flow conditions
In this lecture we characterize the effect of absence of unconstrained thermodynamic equilibrium and onset of a metastable state on the adiabatic flow of a mixture of liquid and its vapor through a convergent-divergent nozzle. We study steady-state flows and emphasize the relations that are present when the flow is choked. In such cases, there exists a cross-section in which the flow is critical and in which the adiabatic wave of small amplitude is stationary. More precisely, the relaxation process which results from the lack of equilibrium causes the system to be dispersive. In such circumstances, the critical velocity is equal to the frozen speed of sound, a/sub f/ corresponding to /omega/ /yields/ /infinity/. The relaxation process displaces the critical cross-section quite far downstream from the throat and places it in the divergent portion of the channel. We present the topological portrait of solutions in a suitably defined state-velocity space and discuss the potential appearance of normal and dispersed shock waves. In extreme cases, the singular point (usually a saddle) which enables the flow to become supercritical is displaced so far that it is located outside the exit. Then, the flow velocity is everywhere subcritical (w < a/sub f/) even though it may exceed the equilibrium speed of sound (w /approx gt/ a/sub e/) beyond a certain cross-section, and in spite of the presence of a throat. 10 refs., 4 figs.
- Research Organization:
- Brown Univ., Providence, RI (USA); Polska Akademia Nauk, Gdansk (Poland). Inst. Maszyn Przeplywowych
- DOE Contract Number:
- FG02-87ER13687
- OSTI ID:
- 5823261
- Report Number(s):
- CONF-890856-1; ON: DE89008634
- Resource Relation:
- Conference: IUTAM symposium, Gottingen, Germany, F.R., 28 Aug - 1 Sep 1989; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
Similar Records
Two-phase flow in a vertical pipe and the phenomenon of choking: Homogeneous diffusion model. Part I. Homogeneous flow models
Improvements in the reactor core isolation cooling (RCIC) pump model
Related Subjects
SUPERCONDUCTIVITY AND SUPERFLUIDITY
42 ENGINEERING
TWO-PHASE FLOW
THERMODYNAMICS
CRITICAL FLOW
EQUATIONS
NOZZLES
PHASE DIAGRAMS
SHOCK WAVES
STEADY FLOW
DIAGRAMS
FLUID FLOW
640410* - Fluid Physics- General Fluid Dynamics
420400 - Engineering- Heat Transfer & Fluid Flow