Analysis of fluid hammer occurrence with phase change and column separation due to fast valve opening by means of flow visualization

Lema, Marcos; Peña, Fernando López; Buchlin, Jean‐Marie; Rambaud, Patrick; Steelant, Johan

doi:10.1016/j.expthermflusci.2016.07.008

Cited by 11 publications

(6 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Column separation mainly occurs when the pressure in the pipeline drops below the liquid vapor pressure at specific locations, such as the closed end of the present experimental configuration, and is observed with flow visualization in [6] and [29]. The present analysis seeks to understand the physics of the column separation occurrence right after the first fluid hammer pressure peak, based on the resolution of the momentum equation.…”

Section: Liquid Column Separation Mechanismmentioning

confidence: 97%

“…Published experimental evidence obtained with high speed imaging by Lema et al [6] shows that the liquid front approaching the end of the tube (as in figure 4(a)) is not uniform and appears as a foamy mixture of liquid and gas extending over a considerable pipe length of at least 25 pipe diameters. It is due to the ocurrence of cavitation at the front, plus the effects of the finite opening time of the FOV.…”

Section: Liquid Column Separation Mechanismmentioning

confidence: 98%

“…However, the fluid hammer not only leads to high-pressure peaks in the fluid but also to regions with low static pressure, such as downstream of fast-closing valve [3][4][5], due to the arrival of an reflected expansion wave after fluid hammer occurrence [6,7], or at knee points of the piping system [8]. These low pressures can reach values that are well below the vapor pressure, thus leading to cavitation.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Liquid Column Separation Due to Fluid Hammer Occurrence in Propellant Lines

Lema

Gosset

Peña

et al. 2023

Journal of Propulsion and Power

Self Cite

View full text Add to dashboard Cite

When a pressurized liquid enters a pipeline with a closed end and under vacuum conditions, the resulting liquid front suddenly is brought to rest at the end of the pipe. This type of flow configuration is found in propulsion systems of satellites during priming operation and induces a fluid hammer followed by a column separation, generating a multiphase gas/vapor bubble. This paper aims at explaining the column separation mechanism by solving the momentum equation for the liquid column moving in the pipeline when column separation occurs and by applying the integral form of the conservation principles to expansion and compression waves within the flow. The resulting model provides the velocity and position of the liquid front during column separation. Thus, the size and duration of the multiphase bubble can be determined, and the variables involved in the process are identified, which helps the analysis of applications where this complex phenomenon is involved. It is shown that the initial velocity of the liquid front during column separation is the main parameter, which itself is a function of the fuel tank pressure and the fluid hammer pressure rise. The comparison of the predictions with experimental data shows an excellent agreement.

show abstract

Section: Liquid Column Separation Mechanismmentioning

confidence: 97%

Section: Liquid Column Separation Mechanismmentioning

confidence: 98%

mentioning

confidence: 99%

See 1 more Smart Citation

Liquid Column Separation Due to Fluid Hammer Occurrence in Propellant Lines

Lema

Gosset

Peña

et al. 2023

Journal of Propulsion and Power

Self Cite

View full text Add to dashboard Cite

show abstract

“…When the valve closing time is gradually increased, different hydraulic transition flow states may occur in the tubeline system. The transient value of pressure in the pressure pipe flow is related to the variation of the velocity in the pipe and the action time [1,5]. With the extension of valve closing time, the reflection wave superposition effect is obvious.…”

Section: Effect Of the Valve Closing Speed On The Water Hammer Pressumentioning

confidence: 99%

“…Due to the complexity of the water hammer with multipoint collapse, relevant formation mechanisms and influencing factors remain unclear [4]. In certain conditions, such as when a pipeline valve is quickly opened or closed or when a pump is accidentally activated or stopped, water hammer pressure fluctuations may occur [5,6]. When the pressure in the pipe drops to the vapor pressure level of the liquid, it will…”

Section: Introductionmentioning

confidence: 99%

An Experimental Study on the Water Hammer with Cavity Collapse under Multiple Interruptions

Yang

Wang

et al. 2020

Water

View full text Add to dashboard Cite

Pressurized pipeline system damage is primarily caused by the highly destructive water hammer force. Currently, research on water hammer-caused collapse is mostly based on single-point collapse cases, but water hammer research, which involves multipoint collapse, is insufficient. Here, we establish an experimental platform to realize water hammers with multipoint collapse. With different schemes, i.e., various initial flow rates and valve closing speeds, we observed the hydraulic transient process with a high-speed camera, analyzed its characteristics and explained experimental phenomena with theoretical knowledge. Using experimental data analysis, we summarized the influencing factors and laws of the cavity length and water hammer pressure. Flow and pressure data for the different schemes were recorded to provide basic simulation data. Water column separation experimental phenomena were observed: completely atomized, completely cavitated and partially cavitated, and both cavitated and atomized. At the pump outlet, three hydraulic transition states occurred simultaneously in the horizontal pipe section: completely atomized, completely cavitated, and both cavitated and atomized. Two hydraulic transition states occurred in the knee region: completely and partially cavitated, and without atomization. The experimental results reveal that the initial flow rate and valve closing speed greatly affect the water hammer pressure rise and cavity length. The higher the initial flow rate and valve closing speed are, the larger the water hammer pressure rise and cavity length are.

show abstract