Statistical characterization of liquid film fluctuations during gas-liquid two-phase counter-current flow in a 1/30 scaled-down test facility of a pressurized water reactor (PWR) hot leg

An experimental investigation on CCFL characteristics during gas/low surface tension liquid counter-current two-phase flow in a small-scaling PWR hot leg typical geometry

“…It can be seen in the figure that the curve has a decreasing trend describing that the gas flow rate to initiate the flooding monotonously declines with the increase of the liquid flow rate. Here, as also previously reported by Astyanto et al [14,18], as the liquid flow rate increases, the liquid film thickness increases and causes a narrower area to be pass by the gas. The more the narrow the area left, the faster the liquid blockage is reached.…”

“…On the basis of experimental investigations, studies on the basis of visualizations have been largely introduced [2,[5][6][7][8] through detailed identifications of the obtained flow structures. Here, the mechanisms leading to flooding have been visually observed and supported by signal characterizations obtained by physical measurements such as pressures [9,10] as well as phasic fractions [11]. Subsequently, through these visual observations, CCFL has been largely reported to be characterized through a curve representing the phasic superficial velocity when the transition is initiated, well-known as CCFL characteristic curves.…”

“…The experiments were carried out during a research framework to investigate the characteristics of counter-current flow in a small-scale facility representing a down-scaled model of German-Konvoi PWR primary circuit [9][10][11][12]13,14]. The experiment apparatus, which is schematically depicted in Figure 1, has been particularly developed in the Laboratory of Fluid Mechanics and Heat Transfers of Universitas Gadjah Mada, Indonesia.…”

“…The experiment apparatus, which is schematically depicted in Figure 1, has been particularly developed in the Laboratory of Fluid Mechanics and Heat Transfers of Universitas Gadjah Mada, Indonesia. Details of construction of the facility, comprising the fluid supply and lighting systems, and also experimental procedures including the measurement techniques are described by previous reports [9][10][11][12]13]. Therefore, in the present reports only the test section is briefly explained in the following.…”

Countercurrent Flow Limitation in a Pipeline with an Orifice

“…For vertical channels, horizontal channels, and inclined channels, a series of experimental and theoretical studies have been performed to instigate the geometric and the fluid properties effect of CCFL [4][5][6][7][8][9][10][11][12]. In particular, the possible occurrence of CCFL in the hot leg of a PWR during SBLOCA or LOCA accidents is of special interest for nuclear safety research; therefore, large numbers of experimental investigations and numerical studies have been carried out on these topics in recent years [13][14][15][16][17][18][19].…”