Analysis of flow field in Si3N4 dry granulation chamber with non-standard composite structure

In order to improve the whirling phenomenon of Si3N4 particles in the granulation chamber, the influence of the structure of the granulation chamber on the internal distribution is explored. Euler Euler’s two-phase flow model is established. The flow field in the combined structure granulation chamber with different layout is simulated. The volume distribution and velocity field change of Si3N4 particles in the combined structure granulation chamber with different layout are analyzed. The results show that the angle between two adjacent composite structures is 20∘, 60∘, 80∘ and completely standard the Si3N4 particles with volume fraction index greater than 0.8 account for 10.2%, 11.5%, 12.5% and 6.7% of the total volume respectively. When the combined structure is completely standard, several small convolutions are found. The whirling phenomenon in the granulation chamber is improved. When the angle between two adjacent composite structures is 20∘, 60∘, 80∘ and complete standard, the proportion of qualified particles is 59%, 64%, 66% and 68%. The fluidity index is 84, 85, 87 and 88, respectively. To sum up, the combination structure of the granulation chamber is a complete standard, it is beneficial to improve the spin phenomenon of Si3N4 particles in the granulation chamber.

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Status of Advanced Two-Phase Flow Model Development for SRM Chamber Flow Field and Combustion Modeling

10.21236/ada427829 ◽

2004 ◽

Author(s):

Gary Luke ◽

Mark Eagar ◽

Michael Sears ◽

Scott Felt ◽

Bob Prozan

Keyword(s):

Flow Field ◽

Flow Model ◽

Two Phase Flow ◽

Model Development ◽

Phase Flow ◽

Two Phase ◽

Combustion Modeling

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Optimizing the cleanliness in multi-segment disk amplifiers based on vector flow schemes

High Power Laser Science and Engineering ◽

10.1017/hpl.2017.36 ◽

2018 ◽

Vol 6 ◽

Cited By ~ 6

Author(s):

Zhiyuan Ren ◽

Jianqiang Zhu ◽

Zhigang Liu ◽

Xiaowei Yang

Keyword(s):

Flow Field ◽

Particle Concentration ◽

Flow Model ◽

Three Dimensional ◽

Phase Flow ◽

Three Dimensional Flow ◽

Two Phase ◽

Key Factor ◽

Measurement Experiment ◽

Laser Induced Damage

The objective of maintaining the cleanliness of the multi-segment disk amplifier in Shenguang-II (SG-II) is to reduce laser-induced damage for optics. The flow field of clean gas, which is used for the transportation of contaminant particles, is a key factor affecting the cleanliness level in the multi-segment disk amplifier. We developed a gas–solid coupling and three-dimensional flow numerical simulation model. The three-dimensional and two-phase flow model is verified by the flow-field smog experiment and the particle concentration measurement experiment with the 130-disk amplifier in SG-II. By optimizing the boundary conditions with the same flow rate, the multi-inlet vector flow scheme can not only effectively reduce the purging time, but also prevent the reverse diffusion of contaminant particles in the multi-segment disk amplifier and the deposition of contaminant particles on the surface of the Nd:glass.

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An Efficient Unsteady Two-Phase Flow Model for Cathode Gas Channels of a Polymer Electrolyte Fuel Cell

ASME 2011 9th International Conference on Fuel Cell Science, Engineering and Technology ◽

10.1115/fuelcell2011-54954 ◽

2011 ◽

Author(s):

Suman Basu ◽

Ashok Gopinath

Keyword(s):

Fuel Cell ◽

Flow Field ◽

Polymer Electrolyte ◽

Liquid Water ◽

Test Performance ◽

Flow Model ◽

Two Phase Flow ◽

Polymer Electrolyte Fuel Cell ◽

Phase Flow ◽

Two Phase

The importance of flow field design in a Polymer Electrolyte Fuel Cell (PEFC) cannot be overemphasized. Experimental evidence suggests the presence of a significant amount of liquid water in the PEFC gas channels and a typical driving cycle in a city suggests that a vehicular PEFC engine is unlikely to reach steady state operation under these conditions. Therefore the need for an unsteady two-phase flow model is critical. The “Multiphase Mixture” (M2) model is used to develop an efficient unsteady two-phase flow model for the cathode gas channels. Liquid water evolution in cathode gas channels and its effect on the cathode pressure drop history is investigated with the help of the model. It is an efficient tool to evaluate the performance of new flow field designs as well as to test performance loss due to channel blockage. The same model could be extended to anode gas channels.

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An Innovative Two-Phase Flow Pump and Separator Solution

Volume 4: Cycle Innovations; Fans and Blowers; Industrial and Cogeneration; Manufacturing Materials and Metallurgy; Marine; Oil and Gas Applications ◽

10.1115/gt2011-46917 ◽

2011 ◽

Author(s):

Franc¸ois Gruselle ◽

Johan Steimes ◽

Patrick Hendrick

Keyword(s):

Flow Rate ◽

Flow Model ◽

Two Phase Flow ◽

Volume Fraction ◽

Operating Conditions ◽

Liquid Volume ◽

Phase Flow ◽

Two Phase ◽

Efficient System ◽

Measurement Systems

The Aero-Thermo-Mechanics (ATM) department of Universite´ Libre de Bruxelles (ULB) develops a new system to simultaneously pump and separate a two-phase flow, in particular oil/air mixtures. Two-phase flows are encountered in many applications (oil extraction, flow in nuclear power plant pumps, pulp and paper processing) but the study is mainly focused on aeroengine lubrication systems. The main objective is to obtain a compact and efficient system that can both extract the gas of a two-phase flow and increase the pressure of the liquid phase. Particular care is given to the liquid flow rate lost at the gas outlet of the system. A large range of gas/liquid volume ratio has been studied, leading to different two-phase flow regimes at the inlet of the system (slug, churn or annular flow). After successful tests with water-air prototypes, which have allowed to identify the key design and working parameters, the technology has been implemented for a hot oil-air mixture. This paper presents the test results of the first oil/air prototype under real in-flight operating conditions. The tests with oil/air mixtures were performed on the aeroengine lubrication system test bench of the ATM department. The identification and implementation of appropriate two-phase flow rate measurement systems is an essential contribution to the project. Two attractive measurement systems have been considered: a Coriolis density meter for the volume fraction at the liquid outlet and radio-tracing elements for the measurement of the oil consumption at the air outlet. In parallel, the flow field in the pump and separator system has been studied with commercial CFD (Computational Fluid Dynamics) software packages. The choice of the two-phase flow model is highly dependent on the two-phase flow regime. But different regimes can simultaneously exist in the pump and separator system. So, the Eulerian two-phase flow model, the most complex and general model, seems to be the most appropriate. A coupling of this model with a dispersed phase model is under investigation to take all two-phase flow phenomena into account.

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Analysis of Air–Oil Flow and Heat Transfer inside a Grooved Rotating-Disk System

Processes ◽

10.3390/pr7090632 ◽

2019 ◽

Vol 7 (9) ◽

pp. 632 ◽

Cited By ~ 2

Author(s):

Chunming Li ◽

Wei Wu ◽

Yin Liu ◽

Chenhui Hu ◽

Junjie Zhou

Keyword(s):

Flow Field ◽

Two Phase Flow ◽

Volume Fraction ◽

Rotating Disk ◽

Flow Speed ◽

Phase Flow ◽

Disk System ◽

Two Phase ◽

Flow And Heat Transfer ◽

Oil Flow

An investigation on the two-phase flow field inside a grooved rotating-disk system is presented by experiment and computational fluid dynamics numerical simulation. The grooved rotating-disk system consists of one stationary flat disk and one rotating grooved disk. A three-dimensional computational fluid dynamics model considering two-phase flow and heat transfer was utilized to simulate phase distributions and heat dissipation capability. Visualization tests were conducted to validate the flow patterns and the parametric effects on the flow field. The results indicate that the flow field of the grooved rotating-disk system was identified to be an air–oil flow. A stable interface between the continuous oil phase and the two-phase area could be formed and observed. The parametric analysis demonstrated that the inter moved outwards in the radial direction, and the average oil volume fraction over the whole flow field increased with smaller angular speed, more inlet mass flow of oil, or decreasing disk spacing. The local Nusselt number was remarkably affected by the oil volume fraction and the fluid flow speed distributions in this two-phase flow at different radial positions. Lastly, due to the change of phase volume fraction and fluid flow speed, the variation of the average Nusselt number over the whole flow field could be divided into three stages.

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An Analytical Two-Phase Flow Model for Prediction of Leakage in Wet Gas Labyrinth Seals and Pocket Damper Seals. Is Simplicity Still Desired?

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4051916 ◽

2021 ◽

Author(s):

Jing Yang ◽

Luis San Andres

Keyword(s):

Analytical Model ◽

Flow Model ◽

Two Phase Flow ◽

Volume Fraction ◽

Gas Mixture ◽

Phase Flow ◽

Rotor Speed ◽

Labyrinth Seals ◽

Two Phase ◽

Wet Gas

Abstract Current and upcoming two-phase pump and compression systems in subsea production facilities must demonstrate long-term operation and continuous availability. Annular pressure seals, limiting secondary flow, also influence the dynamic stability of turbomachinery. Hence, it becomes paramount to quantify the leakage and dynamic performance of annular seals operating with a liquid in gas mixture (wet gas). The paper develops a simple analytical model predicting the leakage and cavity pressures for Labyrinth seals and pocket damper seals (PDSs) operating with two-phase flow. The model adapts Neumann's equation with a homogeneous flow model. Predicted leakage for a four-blade PDS operating under a low supply pressure (2.3 and 3.2 bar) and a low rotor speed (5,250 rpm) agree well with experimental results for both a pure gas and a wet gas conditions. For an eight-blade PDS supplied with air at 62.1 bar, discharge pressure 31.1 bar and rotor speed of 15 krpm, the analytical model predicts leakage that is just 2% larger than a CFD prediction. For the PDS supplied with an oil in gas mixture having gas volume fraction = 0.92 ~ 0.98, the simple model delivers leakage that is up to ~ 6% lower than published CFD results. Throughout the life of an oil well that sees radical changes in gas and liquid composition as well as pressure conditions, the expedient model, quick and accurate to estimate leakage in wet gases seals, can be readily integrated into an engineering routine or practice.

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Two-phase modelling of a fluid mixing layer

Journal of Fluid Mechanics ◽

10.1017/s0022112098003127 ◽

1999 ◽

Vol 378 ◽

pp. 119-143 ◽

Cited By ~ 46

Author(s):

J. GLIMM ◽

D. SALTZ ◽

D. H. SHARP

Keyword(s):

Boundary Conditions ◽

Flow Model ◽

Two Phase Flow ◽

Volume Fraction ◽

Mixing Layer ◽

Constitutive Law ◽

Fluid Mixing ◽

Phase Flow ◽

Two Phase ◽

Self Similar Solution

We analyse and improve a recently-proposed two-phase flow model for the statistical evolution of two-fluid mixing. A hyperbolic equation for the volume fraction, whose characteristic speed is the average interface velocity v*, plays a central role. We propose a new model for v* in terms of the volume fraction and fluid velocities, which can be interpreted as a constitutive law for two-fluid mixing. In the incompressible limit, the two-phase equations admit a self-similar solution for an arbitrary scaling of lengths. We show that the constitutive law for v* can be expressed directly in terms of the volume fraction, and thus it is an experimentally measurable quantity. For incompressible Rayleigh–Taylor mixing, we examine the self-similar solution based on a simple zero-parameter model for v*. It is shown that the present approach gives improved agreement with experimental data for the growth rate of a Rayleigh–Taylor mixing layer.Closure of the two-phase flow model requires boundary conditions for the surfaces that separate the two-phase and single-phase regions, i.e. the edges of the mixing layer. We propose boundary conditions for Rayleigh–Taylor mixing based on the inertial, drag, and buoyant forces on the furthest penetrating structures which define these edges. Our analysis indicates that the compatibility of the boundary conditions with the two-phase flow model is an important consideration. The closure assumptions introduced here and their consequences in relation to experimental data are compared to the work of others.

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