scholarly journals Numerical simulation of the process of gas outflow into an open pipe with an obstacle filled with a liquid (water, lead)

2021 ◽  
Vol 2057 (1) ◽  
pp. 012073
Author(s):  
I S Vozhakov ◽  
S I Lezhnin
Keyword(s):  
Numerical Simulation ◽  
Turbulence Model ◽  
Liquid Water ◽  
High Speed ◽  
Numerical Study ◽  
Industrial Applications ◽  
Vof Method ◽  
Gas Jet ◽  
Gas Jets ◽  
Open Pipe

Abstract Submerged gas jets find a wide variety of industrial applications, and their behavior is characterized by the ratio of inertia to buoyancy and can vary from the emergence of individual bubbles to stable jets. A numerical study of the high-speed outflow of gas under a pressure of 18 MPa into a cavity with an obstacle filled with a liquid under a pressure of 2 MPa is carried out. The simulation is performed using the VOF method in conjunction with the k-ε turbulence model. The calculations are realized for three distances between the outflow hole and the obstacle: 100, 200, and 300 mm. Principal scenarios of gas jet evolution and characteristic expiration times are obtained.

scholarly journals Flow Structures of Submerged Gas Jet in Liquid Currents

2021 ◽  
Vol 299 ◽  
pp. 03011
Author(s):  
Ping Dong ◽  
Dong Cheng ◽  
Huixiang Jing ◽  
Guanghua Li ◽  
Bingju Lu ◽  
...  
Keyword(s):  
High Speed ◽  
Video Camera ◽  
Gas Jet ◽  
Flow Structures ◽  
Experimental Setup ◽  
High Speed Video ◽  
Gas Jets ◽  
High Speed Video Camera ◽  
Pod Analysis ◽  
Proper Orthogonal

The flow structure of the submerged gas jet in liquid currents is important to engineering applications. In the present study, the development of a submerged gas jet subjected to liquid current is experimentally investigated to evaluate the effects of the current on the underwater gas jet evolution. A full-scale experimental setup is designed for submerged gas jet release and dispersion in the liquid currents with different velocities. The flow structures of the gas jet are captured by shadow photography combined with a high speed video camera. The experimental images are processed to extract the parameters and perform Proper Orthogonal Decomposition (POD) analysis to reveal the characteristics of different modes standing for different flow structures. It turns out that the flow structures of the gas jets submerged in liquid currents with different velocities are affected by the liquid currents and gas jet pulsation, and the analysis will provide credible assessment and opportunity to take prompt response to control potential accidents caused by the submerged gas jet release in liquid current.

NUMERICAL STUDY OF A TRANSIENT GAS AND PARTICLE FLOW IN A HIGH-SPEED NEEDLE-FREE BALLISTIC PARTICULATE VACCINE DELIVERY SYSTEM

2004 ◽  
Vol 04 (04) ◽  
pp. 559-578 ◽  
Author(s):  
Y. LIU ◽  
M. A. F. KENDALL
Keyword(s):  
Delivery System ◽  
Gas Dynamics ◽  
High Speed ◽  
Numerical Study ◽  
Particle Interaction ◽  
Immunological Response ◽  
Gas Jet ◽  
Conical Nozzle ◽  
Computational Fluid Dynamics Cfd ◽  
Key Features

A unique biolistic method of vaccination is operated by accelerating particulate vaccines with a high-speed gas jet generated by a convergent-divergent conical nozzle to sufficient momentum to penetrate the outer layer of human skin. The targeted cells elicit an immunological response. In this paper, Computational Fluid Dynamics (CFD) is utilized to simulate the operation of a prototype biolistics delivery system. The key features of transient gas dynamics and gas-particle interaction are discussed.

scholarly journals Research of pressure pulsations during gas outlet to closed pipe area with liquid and installed disc barrier

2021 ◽  
Vol 2119 (1) ◽  
pp. 012062
Author(s):  
M V Alekseev ◽  
I S Vozhakov ◽  
S I Lezhnin
Keyword(s):  
Numerical Simulation ◽  
Turbulence Model ◽  
Vof Method ◽  
Maximum Pressure ◽  
Liquid Lead ◽  
Closed Region ◽  
Pressure Pulsations ◽  
Axial Pressure ◽  
Model Calculations ◽  
Gas Volume

Abstract A numerical simulation of the gas outflow to a closed region filled with liquid with a barrier disk was performed. The calculations were carried out using the VOF method, supplemented by the k-e turbulence model. Calculations were performed for three cases of 100, 200, and 300 mm distances of the disk from the injector with a gas outflow into water and liquid lead. The pulsations of axial pressure on a disk obstacle were investigated. It was found that the maximum pressure during pulsations of the upper gas volume in lead can be greater than the pressure in the gas receiver.

Numerical study on the contribution of surface and volume components of flow-induced noise in baffle silencers

2021 ◽  
Vol 263 (1) ◽  
pp. 5283-5290
Author(s):  
Bartosz Chmielewski ◽  
Iván Herrero-Durá ◽  
Paweł Nieradka
Keyword(s):  
Laminar Flow ◽  
High Speed ◽  
Numerical Study ◽  
Power Level ◽  
Calibration Method ◽  
Industrial Applications ◽  
Large Reynolds Number ◽  
Sound Power ◽  
Noise Mitigation ◽  
Cfd Simulations

Baffle silencers are a well-known solution for noise mitigation in industrial applications. One of the issues concerning these devices is the flow-inducted noise produced when a non-laminar flow of the medium in the duct occurs. These situations occur, for example, in dedusting installations or exhaust systems with the high-speed flow (large Reynolds number of the turbulence and small Mach number). This kind of installation has a complex shape that causes a turbulent flow in the medium. Installing a baffle silencer in these conditions causes additional noise. This noise cannot be predicted by using a standard approach with equations for laminar flow conditions. This paper presents the first step of the research in this field. The first step is to find a relation between CFD simulations' results and self-noise of the baffle silencer. In this work, we use the formulation proposed by Proudman in 1952 to calculate the sound power generated by the flow. The formulation is based on the turbulent kinetic energy k and dissipation rate ε of the flow, which is calculated by CFD simulations. The resulting sound power level needs to be calibrated. The calibration method is developed and presented. The aim of this research is to design an experimental setup.

Hydrodynamic Performance and Appendage Considerations of Wave-Piercing Planing Craft Overlapping Waves and Porpoising

2019 ◽  
Author(s):  
Sang-Won Kim ◽  
Sang-Eui Lee ◽  
Gyoung-Woo Lee ◽  
Kwang-Cheol Seo ◽  
Nobuyuki Oshima
Keyword(s):  
Numerical Simulation ◽  
Pressure Distribution ◽  
High Speed ◽  
Numerical Study ◽  
Hydrodynamic Performance ◽  
Moving Mesh ◽  
Navier Stokes ◽  
Hull Form ◽  
Wave Condition ◽  
Planing Craft

Abstract This work addresses the numerical study of wave-piercing planing hull and related hydrodynamic performance as the appendages. From the half century ago, the interest in high-speed planing crafts has been advanced toward maintaining performance stably. The main reasons to make it hard are instability motion occurring from porpoising and wave condition. Porpoising is mainly due to overlap the heaving and pitching motion with certain period, which is caused by instable pressure distribution and changing longitudinal location of center of gravity. In addition, in wave condition, encountering wave disturbs going into planing mode. This paper presents numerical results of wave-piercing planing hull in porpoising and wave condition. Numerical simulation is conducted via Reynolds Averaged Navier-stokes (RANS) with moving mesh techniques (overset grid), performed at different wave condition. The results for the behaviors of wave-piercing hull form are practically presented and investigated in this study. The understanding of these phenomena is important for design of appendages of wave-piercing hull-form.

Gas Jet Injection of Clusters into Liquids

1990 ◽  
Vol 206 ◽  
Author(s):  
Donald L. Johnson ◽  
J. J. Schmitt ◽  
B. L. Halpern
Keyword(s):  
High Speed ◽  
Gas Jet ◽  
Jet Injection ◽  
Gas Jets ◽  
Novel Approach ◽  
Colloid Synthesis

ABSTRACTWe discuss a novel approach to colloid synthesis in which high speed gas jets inject colloid forming species directly into liquids.

Unsteady Numerical and Experimental Study of Cavitation in Axial Pump

2014 ◽  
Vol 4 (1) ◽  
pp. 55-68
Author(s):  
Mohamed Adel ◽  
Nabil H. Mostafa
Keyword(s):  
Numerical Simulation ◽  
Void Growth ◽  
High Speed ◽  
Volume Fraction ◽  
Numerical Study ◽  
Three Dimensional ◽  
Axial Flow ◽  
Two Phase ◽  
Impeller Blade ◽  
Axial Pump

This paper presents an experimental and three-dimensional numerical study of unsteady, turbulent, void growth and cavitation simulation inside the passage of the axial flow pump. In this study a 3D Navier-Stokes code was used (CFDRC, 2008) to model the two-phase flow field around a four blades axial pump. The governing equations are discretized on a structured grid using an upwind difference scheme. The numerical simulation used the standard K-e turbulence model to account for the turbulence effect. The numerical simulation of void growth and cavitation in an axial pump was studied under unsteady calculating. Pressure distribution and vapor volume fraction were completed versus time at different condition. The computational code has been validated by comparing the predicated numerical results with the experiment. The predicted of cavitation growth and distribution on the impeller blade also agreed with that visualized of high speed camera.

Numerical Study of Cavitation on Hydrofoils

2010 ◽  
Vol 44-47 ◽  
pp. 2001-2005
Author(s):  
Jing Hu ◽  
Xian Zhou Wang ◽  
Ming Yue Liu ◽  
Zhi Guo Zhang ◽  
Qi Zhou
Keyword(s):  
Numerical Simulation ◽  
Stokes Equation ◽  
Turbulence Model ◽  
Volume Fraction ◽  
Numerical Study ◽  
Navier Stokes ◽  
Special Focus ◽  
Navier Stokes Equation ◽  
The Relationship ◽  
Incompressible Navier Stokes Equation

Based on CFD technology, flow around a 2-dimentional hydrofoil of highly skewed propeller and NACA series hydrofoils are simulated using 2D incompressible Navier-Stokes equation with Realizable k- turbulence model. In the numerical simulation, the vapor volume fraction is calculated for different cavitation numbers and angles of attack by adding the mixture model. The hydrofoil’s performance and the relationship with hydrofoil parameter are qualitatively analyzed. Special focus is given to the influence of the cavitation numbers and angle of attack on cavitation characteristics.

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