Publication:
Investigation on the interphase drag and wall friction in vertically oriented upward and downward two-phase flows under accident conditions in light water reactors

Дата
2022
Авторы
Blinkov, V. N.
Melikhov, O. I.
Melikhov, V. I.
Kapustin, A. V.
Selkin, S. S.
Journal Title
Journal ISSN
Volume Title
Издатель
Научные группы
Организационные подразделения
Организационная единица
Другие подразделения НИЯУ МИФИ
Структурные подразделения НИЯУ МИФИ, не включенные в состав институтов и факультетов.
Выпуск журнала
Аннотация
© 2022 Elsevier B.V.In this study, applicability of the one-dimensional two-fluid model for predicting the vapor void fraction and the frictional pressure drop in the adiabatic upward and downward two-phase flows has been studied through comparing model predictions with experimental data of Tikhonenko (1973) taken in the 33 mm diameter pipe at system pressure ranging from 2 to 9 MPa, and rated velocity of 0.2 to 2 m/s (mass flux of 170 to 1400 kg⋅m−2 s−1). The experiments reproduce the conditions of the two-phase coolant flow which are expected to occur in the light-water-reactor systems under loss-of-coolant accidents and design extension conditions. It has been found that the existing empirical models for interfacial and wall friction used in the current thermal–hydraulic simulation codes allow adequate prediction of the vapor void fraction and the frictional pressure drop in vertical pipes only for the upward direction of two phase flow. Modeling deficiencies have been identified when these models are applied to the low velocity downward flow. For the downward two-phase flow at a rated velocity of 0.2 m/s (mass flux of 170 kg⋅m−2 s−1), the Lockhart-Martinelli model underpredicts the frictional pressure gradient of the liquid phase which leads to the over-prediction of the average velocity of the liquid phase. As a result, the calculated void fraction is higher compared to the experiment. The possible ways to improve the current models of the wall friction in two-phase flows have been discussed.
Описание
Ключевые слова
Цитирование
Investigation on the interphase drag and wall friction in vertically oriented upward and downward two-phase flows under accident conditions in light water reactors / Blinkov, V.N. [et al.] // Nuclear Engineering and Design. - 2022. - 389. - 10.1016/j.nucengdes.2022.111666
Коллекции