A Nonequilibrium Vapor Production Model for Critical Flow

Hanford Waste Tank Bump Accident and Consequence Analysis

“…Coincidentally, this value of N falls within the range of values for ordinary water (no precipitate particles) containing natural impurities (dust, etc. ), namely 10 to 10 /m (Richter 1981;Abdollahian et al 1982;Ardon 1978;and Rivard and Travis 1980). Some indication of the validity of equation (B-13) can be given by considering the Lipkis et al (1956) experimental study of boiling in a volumetrically-heated aqueous KOH solution pool.…”

Test de lois interfaciales de génération de vapeur avec l'expérience Super Moby Dick

“…1 Les auteurs qui choisissent r [11,14] considèrent qu'une bulle croît jusqu'à la taille critique où son fractionnement en deux bulles est dû à la turbulence du liquide. Le rayon maximum rmax, donné par un nombre de Weber critique, est 1.25 fois le rayon des 2 bulles résultantes ce qui incite les auteurs cités à prendre: (12) r < es où l'expression entre crochet est par définition le nombre de Jakob Ja.…”

Mechanistic Imonequilibrium Modeling of Critical Flashing Flow of Subcooled Liquids Containing Dissolved Noncondensables

“…Nonequilibrium mechanistic models based on the numerical solution of the two-fluid conservation equations represent an advanced group of two-phase critical flow models and can account for the integral flow effects on local flow properties at the critical cross section [7][8][9][10][11][12][13][14][15]. In these models the one-dimensional (I-D) phasic conservation equations are numerically solved for flow through a channel and by iteratively varying the channel discharge rate, the flow rate leading to the critical conditions at the channel throat, i.e., an infinitely large pressure gradient [10,12,IS]; a vanishing determinant of the coefficient matrix for the system of I-D, quasi-linear first-order differential equations representing the phasic conservation equations [11,13,16]; or a flow rate independent of downstream pressure [8,14] is specified.…”

“…In these models the one-dimensional (I-D) phasic conservation equations are numerically solved for flow through a channel and by iteratively varying the channel discharge rate, the flow rate leading to the critical conditions at the channel throat, i.e., an infinitely large pressure gradient [10,12,IS]; a vanishing determinant of the coefficient matrix for the system of I-D, quasi-linear first-order differential equations representing the phasic conservation equations [11,13,16]; or a flow rate independent of downstream pressure [8,14] is specified. The major difficulty, which also accounts for the disagreement among these models, is the treatment of the poorly understood bubble nucleation processes.…”

“…The assumed bubble number densities and sizes vary significantly among investigators. Ardron [7] assumed N = 10 6 m-3 , Rivard and Travis [8] used N = 10 3 kg-I, Refs. [10][11][12] all assumed N = 10 11 m":', and Dagan et al [15] correlated N as a function of the channel length-to-diameter ratio.…”