A novel representation of the surface tension force for two-phase flow with reduced spurious currents

2006 ◽  
Vol 195 (44-47) ◽  
pp. 6239-6257 ◽  
Author(s):  
E. Aulisa ◽  
S. Manservisi ◽  
R. Scardovelli
Keyword(s):  
Surface Tension ◽  
Two Phase Flow ◽  
Surface Tension Force ◽  
Tension Force ◽  
Phase Flow ◽  
Two Phase ◽  
Spurious Currents

Numerical Investigation of Two-Phase Flow Over Unglazed Plate Collector Covered With Porous Material of Wire Screen for Solar Water Heater Application

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
T. Salameh ◽  
Y. Zurigat ◽  
A. Badran ◽  
C. Ghenai ◽  
M. El Haj Assad ◽  
...  
Keyword(s):  
Surface Tension ◽  
Porous Material ◽  
Water Flow ◽  
Two Phase Flow ◽  
Volume Fraction ◽  
Phase Flow ◽  
Two Phase ◽  
Solar Water ◽  
Wire Screen ◽  
Effect Of Surface

This paper presents three-dimensional numerical simulation results of the effect of surface tension on two-phase flow over unglazed collector covered with a wire screen. The homogenous model is used to simulate the flow with and without the effect of porous material of wire screen and surface tension. The Eulerian-Eulerian multiphase flow approach was used in this study. The phases are completely stratified, the interphase is well defined (free surface flow), and interphase transfer rate is very large. The liquid–solid interface, gas–liquid interface, and the volume fraction for both phases were considered as boundaries for this model. The results show that the use of porous material of wire screen will reduce the velocity of water flow and help the water flow to distribute evenly over unglazed plate collector. The possibility of forming any hot spot region on the surface was reduced. The water velocity with the effect of surface tension was found higher than the one without this effect, due to the extra momentum source added by surface tension in longitudinal direction. The use of porous material of wires assures an evenly distribution flow velocity over the inclined plate, therefore helps a net enhancement of heat transfer mechanism for unglazed solar water collector application.

Large Eddy Simulation of Two-Phase Flow Pattern and Transformation Characteristics of Flow Mixing Nozzle

2019 ◽  
Vol 35 (5) ◽  
pp. 693-704
Author(s):  
Jin Zhao ◽  
Zhi Ning ◽  
Ming Lü
Keyword(s):  
Flow Pattern ◽  
Two Phase Flow ◽  
Velocity Ratio ◽  
Inertial Force ◽  
Surface Tension Force ◽  
Viscous Force ◽  
Phase Flow ◽  
Two Phase ◽  
Jet Breakup ◽  
Flow Mixing

ABSTRACTThe two-phase flow pattern of a flow mixing nozzle plays an important role in jet breakup and atomization. However, the flow pattern of this nozzle and its transformation characteristics are still unclear. A diesel-air injection simulation model of a flow mixing nozzle is established. Then the two-phase flow pattern and transformation characteristics of the flow mixing nozzle is studied using a numerical simulation method. The effect of the air-diesel velocity ratio, ratio of the distance between the tube orifice and nozzle hole and the tube diameter (H/D), and the diesel inlet velocity was studied in terms of the jet breakup diameter (jet diameter at the breakup position) and jet breakup length (length of the diesel jet from the breakup position to the nozzle outlet). The results show that the jet breakup diameter decreases with the decrease in H/D or the increase in the air-diesel velocity ratio and diesel inlet velocity. The jet breakup length increases first and then decreases with the increase in H/D and air-diesel velocity ratio; the trend of the diesel inlet velocity is complicated. In addition, a change in the working conditions also causes some morphological changes that cannot be quantitatively analyzed in the diesel-air flow pattern. The transition characteristics of the flow pattern are analyzed, and it is found that the main reason for the change in the flow pattern is the change in the inertial force of the air, surface tension force, and viscous force of diesel (non-dimensional Reynolds number and Weber number describe the transition characteristics in this paper). The surface tension force of diesel decreases and the viscous force of diesel and inertial force of air increase when the air-diesel velocity ratio increases or H/D decreases. However, the effects of the diesel surface tension force and viscous force effect are much smaller than that of the air inertial force, which changes the diesel-air flow pattern from a drop pattern to a vibration jet pattern, broken jet pattern, and then a chaotic jet pattern.

The Impact of Surface Tension on the Oil-Water Stratified Flow

2011 ◽  
Vol 383-390 ◽  
pp. 826-829 ◽  
Author(s):  
Dao Zhen Xu ◽  
Guo Zhong Zhang ◽  
Xin Zhang
Keyword(s):  
Surface Tension ◽  
Two Phase Flow ◽  
Large Diameter ◽  
Phase Flow ◽  
Two Phase ◽  
Horizontal Pipe ◽  
Diameter Pipe ◽  
Small Density ◽  
Oil Water ◽  
The Impact

The stratified water-oil two—phase flow was modeled using VOF method in horizontal pipe and surface tension was taken into consideration using CSF model. It was found that the surface tension had great impact on the small density difference two-phase flow even in large diameter pipe, which would lead the interface curved and pressure gradient increased.

Effect of Surface Tension on Flow Pattern in Counter-Current Gas-Liquid Two-Phase Flow in an Inclined Pipe

2004 ◽  
Vol 2004.42 (0) ◽  
pp. 369-370
Author(s):  
Deendarlianto ◽  
Masafumi Konishi ◽  
Akiharu Ousaka ◽  
Akira Kariyasaki ◽  
Koji Kusano
Keyword(s):  
Surface Tension ◽  
Flow Pattern ◽  
Two Phase Flow ◽  
Phase Flow ◽  
Two Phase ◽  
Inclined Pipe ◽  
Counter Current ◽  
Effect Of Surface

Experimental Investigation of the Effect of Surface Tension and the Correlation on Void Fraction and Frictional Pressure Drop of an Air-Liquid Two-Phase Flow in a Horizontal Flat Capillary Rectangular Channel

2003 ◽  
Author(s):  
Hideo Ide ◽  
Tohru Fukano
Keyword(s):  
Surface Tension ◽  
Pressure Drop ◽  
Void Fraction ◽  
Two Phase Flow ◽  
Rectangular Channel ◽  
Surfactant Solution ◽  
Phase Flow ◽  
Two Phase ◽  
Frictional Pressure Drop ◽  
Effect Of Surface

Air-liquid two-phase flow in a horizontal flat capillary rectangular channel has been studied to clarify the effects of concentration of surfactant solution on the flow phenomena, such as flow patterns, pressure drop, void fraction and so on. The concentrations of surfactant solution were 0, 10, 50 and 100 ppm and the surface tension of each solution was reduced to about 34mN/m from that of pure water of about 72mN/m. The dimension of the channel used was 10.0 mm × 1.0 mm. The drag reduction by mixing the surfactant was examined in both the single phase flow and the two-phase flow. The experimental data of two-phase frictional pressure drop and holdup were compared with the respective correlations which were previously proposed by the other researchers and the present authors. Finally, we proposed new correlations of two-phase frictional pressure drop and holdup in which the effect of surface tension and the aspect ratio of cross section of channel were taken into account.

Sign in / Sign up

Export Citation Format

Share Document