Assessment of an Open-Source Pressure-Based Real Fluid Model for Transcritical Jet Flows

Two-fluid model simulations of a bubbly vertical jet are presented. The purpose of these simulations is to assess the modeling of turbulence dispersion and lift forces in a free shear flow. Although turbulence dispersion forces have previously been validated using simpler canonical flows and microscopic particles or bubbles, there was a need to asses the model performance for larger bubbles in more turbulent flows. This method, of validating two-fluid models in flows of increasing complexity has the advantage of excluding, or at least minimizing, the possibility of cancellation of errors when modeling several forces. In a companion paper (see Part-II), the present two-fluid model is extended to a boundary layer in which forces induced by the presence of a wall are important. The turbulent dispersion models used herein are based on the application of a kinetic transport equation, similar to Boltzmann’s equation, to obtain the turbulent diffusion force for the dispersed phase [1, 2]. They have already been constituted and validated for the case of particles in homogeneous turbulence and jets [3] and for microscopic bubbles in grid generated turbulence and mixing layers [4]. It was found that it is possible to simulate the experimental data in Ref. [5] (See Figures-1 to 4) for a bubbly jet with 1 mm diameter bubbles. Good agreement is obtained using the model of Brucato et al. [7] for the modulation of the drag force by the liquid phase turbulence and a constant lift coefficient, CL. However, little sensitivity is observed to the value of the lift coefficient in the range 0 < CL < 0.29.

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A CFD Model for Real Gas Flows

Volume 1: Aircraft Engine; Marine; Turbomachinery; Microturbines and Small Turbomachinery ◽

10.1115/2000-gt-0518 ◽

2000 ◽

Cited By ~ 4

Author(s):

Carlo Cravero ◽

Antonio Satta

Keyword(s):

Numerical Solutions ◽

Turbulence Modeling ◽

Stokes Equations ◽

Fluid Model ◽

Industrial Applications ◽

Navier Stokes ◽

Gas Flows ◽

Navier Stokes Equations ◽

Real Fluid ◽

Solution Methods

Numerical solutions of Navier-Stokes equations are nowadays widely used for several industrial applications in different fields (aerodynamic, propulsion, naval, combustion, etc..), but the solution methods still require significant improvements especially in two aspects: turbulence modeling and fluid modeling. The paper describes in some detail a real fluid model based on Redlich-Kwong-Aungier equation of state and its implementation into a Navier-Stokes solver developed by the authors for turbomachinery flows analysis.

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VasoTracker, a Low-Cost and Open Source Pressure Myograph System for Vascular Physiology

Frontiers in Physiology ◽

10.3389/fphys.2019.00099 ◽

2019 ◽

Vol 10 ◽

Cited By ~ 6

Author(s):

Penelope F. Lawton ◽

Matthew D. Lee ◽

Christopher D. Saunter ◽

John M. Girkin ◽

John G. McCarron ◽

...

Keyword(s):

Open Source ◽

Low Cost ◽

Source Pressure ◽

Vascular Physiology ◽

Pressure Myograph

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Towards Understanding the Structure of Subcritical and Transcritical Liquid–Gas Interfaces Using a Tabulated Real Fluid Modeling Approach

Energies ◽

10.3390/en14185621 ◽

2021 ◽

Vol 14 (18) ◽

pp. 5621

Author(s):

Sajad Jafari ◽

Hesham Gaballa ◽

Chaouki Habchi ◽

Jean-Charles de Hemptinne

Keyword(s):

Equations Of State ◽

Fluid Model ◽

Thermodynamic Characteristics ◽

Diffuse Interface ◽

Numerical Schemes ◽

Two Phase ◽

Jet Mixing ◽

Fuel Atomization ◽

Real Fluid ◽

Rfm Model

A fundamental understanding and simulation of fuel atomization, phase transition, and mixing are among the topics researchers have struggled with for decades. One of the reasons for this is that the accurate, robust, and efficient simulation of fuel jets remains a challenge. In this paper, a tabulated multi-component real-fluid model (RFM) is proposed to overcome most of the limitations and to make real-fluid simulations affordable. Essentially, a fully compressible two-phase flow and a diffuse interface approach are used for the RFM model, which were implemented in the CONVERGE solver. PISO and SIMPLE numerical schemes were modified to account for a highly coupled real-fluid tabulation approach. These new RFM model and numerical schemes were applied to the simulation of different fundamental 1-D, 2-D, and 3-D test cases to better understand the structure of subcritical and transcritical liquid–gas interfaces and to reveal the hydro-thermodynamic characteristics of multicomponent jet mixing. The simulation of a classical cryogenic injection of liquid nitrogen coaxially with a hot hydrogen jet is performed using thermodynamic tables generated by two different equations of state: Peng–Robinson (PR) and Soave–Redlich–Kwong (SRK). The numerical results are finally compared with available experimental data and published numerical studies with satisfactory agreement.

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Comparison of the Performance of Open-Source and Commercial CFD Packages for Simulating Supersonic Compressible Jet Flows

2018 Ivannikov Memorial Workshop (IVMEM) ◽

10.1109/ivmem.2018.00019 ◽

2018 ◽

Cited By ~ 2

Author(s):

Ahmad Al-Zoubi ◽

Jorn Beilke ◽

Victoria N. Korchagova ◽

Sergei V Strizhak ◽

Matvey V. Kraposhin

Keyword(s):

Open Source ◽

Jet Flows ◽

Compressible Jet

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Computations of Particle-Laden Turbulent Jet Flows Based on Eulerian Model

Journal of Fluids Engineering ◽

10.1115/1.4025364 ◽

2013 ◽

Vol 136 (1) ◽

Cited By ~ 14

Author(s):

Pandaba Patro ◽

Sukanta K. Dash

Keyword(s):

Gas Flow ◽

Fine Particles ◽

Solid Phase ◽

Fluid Model ◽

Particle Diameter ◽

Velocity Profiles ◽

Solid Particles ◽

Jet Flows ◽

Particle Sizes ◽

Turbulent Characteristics

Numerical simulations using an Eulerian two-fluid model were performed for spatially developing, two-dimensional, axisymmetric jets issued from a 30-mm-diameter circular nozzle. The nozzle was simulated separately for various flow conditions to get fully developed velocity profiles at its exit. The effect of interparticle collisions in the nozzle gives rise to solids pressure and viscosity, which are modeled using kinetic theory of granular flows (KTGF). The particle sizes are in the range of 30 μm to 2 mm, and the particle loading is varied from 1 to 5. The fully developed velocity profiles are expressed by power law, U=Uc(1-(r/R))N. The exponent, N, is found to be 0.14 for gas phase, irrespective of particle sizes and particulate loadings. However, the solid-phase velocity varies significantly with the particle diameter. For particle sizes up to 200 μm, the exponent is 0.12. The center line velocity (Uc) of the solid phase decreases and, hence, the slip velocity increases as the particle size increases. For 1 mm and 2 mm size particles, the exponent is found to be 0.08 and 0.05, respectively. The developed velocity profiles of both the phases are used as the inlet velocities for the jet simulation. The modulations on the flow structures and turbulent characteristics of gas flow due to the solid particles with different particle sizes and loadings are investigated. The jet spreading and the decay of the centerline mean velocity are computed for all particle sizes and loadings considered under the present study. Additions of solid particles to the gas flow significantly modulate the gas turbulence in the nozzle as well as the jet flows. Fine particles suppress the turbulence, whereas coarse particles enhance it.

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