A Nonlinear k-ε-kp Two-Phase Turbulence Model

2003 ◽  
Vol 125 (1) ◽  
pp. 191-194 ◽  
Author(s):  
L. X. Zhou ◽  
H. X. Gu
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Turbulence Model ◽  
Computation Time ◽  
Second Order ◽  
Phase Correlation ◽  
Order Moment ◽  
Reynolds Stresses ◽  
Two Phase ◽  
Particle Flows

Nonlinear relationships of two-phase Reynolds stresses with the strain rates together with the transport equations of gas and particle turbulent kinetic energy and the two-phase correlation turbulent kinetic energy are proposed as the nonlinear k-ε-kp turbulence model. The proposed model is applied to simulate swirling gas-particle flows. The predicted two-phase time-averaged velocities and Reynolds stresses are compared with the PDPA measurements and those predicted using the second-order moment model. The results indicate that the nonlinear k-ε-kp model has the modeling capability near to that of the second-order moment model, but the former can save much computation time than the latter.

Statistical Modeling of Stratified Two-Phase Flow

2017 ◽  
Vol 3 (2) ◽  
Author(s):  
M. Benz ◽  
T. Schulenberg
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Turbulence Model ◽  
Input Parameter ◽  
Wave Number ◽  
Energy Potential ◽  
Two Phase ◽  
Turbulent Length Scale ◽  
Inner Region ◽  
Velocity Turbulence

A new numerical model for stratified two-phase flows with wavy interface is derived in this study. Assuming an equilibrium condition between turbulent kinetic energy, potential energy, and surface energy, the turbulent length scale in the inner region of a two-layer turbulence approach can be described by a statistical model to account for the influence of the waves. The average wave number, which is an input parameter to this model, is taken from wave spectra. They can be predicted from a Boltzmann statistic of turbulent kinetic energy. The new turbulence model is compared with the two-phase k–ϵ turbulence model. Time-averaged flow properties calculated by the new approach, such as velocity, turbulence, and void profiles, are shown to be in good agreement with experimental data.

Simulation of Swirling Gas-Particle Flows Using Different Time Scales for the Closure of Two-Phase Velocity Correlation in the Second-Order Moment Two-Phase Turbulence Model1

2003 ◽  
Vol 125 (2) ◽  
pp. 247-250 ◽  
Author(s):  
Y. Yu ◽  
L. X. Zhou ◽  
C. G. Zheng ◽  
Z. H. Liu
Keyword(s):  
Phase Velocity ◽  
Time Scale ◽  
Second Order ◽  
Order Moment ◽  
Velocity Correlation ◽  
Two Phase ◽  
Fluctuation Velocity ◽  
Particle Flows ◽  
Measured Particle ◽  
Different Time Scales

Three different time scales—the gas turbulence integral time scale, the particle relaxation time, and the eddy interaction time—are used for closing the dissipation term in the transport equation of two-phase velocity correlation of the second-order moment two-phase turbulence model. The mass-weighted averaged second-order moment (MSM) model is used to simulate swirling turbulent gas-particle flows with a swirl number of 0.47. The prediction results are compared with the PDPA measurement results taking from references. Good agreement is obtained between the predicted and measured particle axial and tangential time-averaged velocities. There is some discrepancy between the predicted and measured particle axial and tangential fluctuation velocities. The results indicate that the time scale has an important effect. It is found that the predictions using the eddy interaction time scale give the right tendency—for example, the particle tangential fluctuation velocity is smaller than the gas tangential fluctuation velocity, as that given by the PDPA measurements.

A K—ε—γ equation turbulence model

1992 ◽  
Vol 237 ◽  
pp. 301-322 ◽  
Author(s):  
Ji Ryong Cho ◽  
Myung Kyoon Chung
Keyword(s):  
Kinetic Energy ◽  
Turbulent Kinetic Energy ◽  
Turbulence Model ◽  
Mixing Layer ◽  
Spreading Rate ◽  
Reynolds Stresses ◽  
Mean Velocity ◽  
Model Equations ◽  
Entrainment Effect ◽  
Intermittency Factor

By considering the entrainment effect on the intermittency in the free boundary of shear layers, a set of turbulence model equations for the turbulent kinetic energy k, the dissipation rate ε, and the intermittency factor γ is proposed. This enables us to incorporate explicitly the intermittency effect in the conventional K–ε turbulence model equations. The eddy viscosity νt is estimated by a function of K, ε and γ. In contrast to the closure schemes of previous intermittency modelling which employ conditional zone averaged moments, the present model equations are based on the conventional Reynolds averaged moments. This method is more economical in the sense that it halves the number of partial differential equations to be solved. The proposed K–ε–γ model has been applied to compute a plane jet, a round jet, a plane far wake and a plane mixing layer. The computational results of the model show considerable improvement over previous models for all these shear flows. In particular, the spreading rate, the centreline mean velocity and the profiles of Reynolds stresses and turbulent kinetic energy are calculated with significantly improved accuracy.

scholarly journals Hydrodynamic Modeling of Swirling Binary Mixture Gas–Particle Flows Using a Second-Order-Moment Turbulence Model

ACS Omega ◽  
2020 ◽  
Vol 5 (49) ◽  
pp. 31490-31501
Author(s):  
Yang Liu ◽  
Ziyun Chen ◽  
Yongju Zhang ◽  
Lixing Zhou
Keyword(s):  
Binary Mixture ◽  
Turbulence Model ◽  
Hydrodynamic Modeling ◽  
Second Order ◽  
Order Moment ◽  
Particle Flows

Numerical Simulation of Gas-Particle Turbulent Flow Using kg-εg -kp-εp-kpg-θ Turbulence Model

2012 ◽  
Vol 204-208 ◽  
pp. 4327-4331 ◽  
Author(s):  
Zhuo Xiong Zeng ◽  
Feng Xue ◽  
Yi Hua Xu
Keyword(s):  
Kinetic Energy ◽  
Phase Velocity ◽  
Turbulent Kinetic Energy ◽  
Turbulence Model ◽  
Present Model ◽  
Particle Interaction ◽  
Particle Collision ◽  
Sudden Expansion ◽  
Velocity Correlation ◽  
Two Phase

kg-εg-kp-εp-kpg-θ turbulence model is proposed which considers particle-particle collision and gas-particle turbulence. This model includes turbulent kinetic energy equation, turbulent kinetic energy dissipation rate equation, particle pseudo-temperature transportation equation and the two-phase velocity correlation transport equation. To close the turbulence model, algebraic expressions of two-phase Reynolds stresses and two-phase velocity correlation variable are established which considered both gas-particle interaction and anisotropy. This model is used to simulate gas-particle in swirling sudden-expansion chamber. Comparing with kg-εg-kp-εp-θ model which is simply closed using a semi-empirical dimensional analysis, the present model has better predicted capability. It is shown that the present model gives simulation results in much better agreement with the experimental results than the kg-εg-kp-εp-θ model.

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