On the Maxwell gas-wall interaction model for micro/nano gas flows

DEVELOPMENT OF DROP/WALL INTERACTION MODEL FOR APPLICATION IN ENGINE CONDITIONS

Atomization and Sprays ◽

10.1615/atomizspr.2020032858 ◽

2020 ◽

Vol 30 (3) ◽

pp. 153-170

Author(s):

Yaoyu Pan ◽

Xiufeng Yang ◽

Song-Charng Kong ◽

Chol-Bum M. Kweon

Keyword(s):

Interaction Model ◽

Wall Interaction

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Effect of Spray-Wall Interaction On Thermoacoustic Instability Prediction by Flame Transfer Function and the Convective Time Delay Method

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.4051639 ◽

2021 ◽

Author(s):

Sheng Meng ◽

Man Zhang

Keyword(s):

Time Delay ◽

Transfer Function ◽

Numerical Models ◽

Time Lag ◽

Interaction Model ◽

Phase Lag ◽

Thermoacoustic Instability ◽

Spray Flame ◽

Wall Interaction ◽

Definition Of

Abstract This study numerically investigates the effect of spray-wall interactions on thermoacoustic instability prediction. The LES-based flame transfer function (FTF) and the convective time delay methods are used by combining the Helmholtz acoustic solver to predict a single spray flame under the so-called slip and film spray-wall conditions. It is found that considering more realistic film liquid and a wall surface interaction model achieves a more accurate phase lag in both of the time lag evaluations compared to the experimental results. Additionally, the results show that a new time delay exists between the liquid film fluctuation and the unsteady heat release, which explains the larger phase value in the film spray-wall condition than in the slip condition. Moreover, the prediction capability of the FTF framework and the convective time delay methodology in the linear regime are also presented. In general, the instability frequency differences predicted using the FTF framework under the film condition are less than 10 Hz compared with the experimental data. However, an underestimation of the numerical gain value leads to requiring a change in the forcing position and an improvement in the numerical models. Due to the ambiguous definition of the gain value in the convective time delay method, this approach leads to arbitrary and uncertain thermoacoustic instability predictions.

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Modeling of Wall Friction for Multispecies Solid-Gas Flows

Journal of Fluids Engineering ◽

10.1115/1.3242608 ◽

1986 ◽

Vol 108 (4) ◽

pp. 486-488 ◽

Cited By ~ 1

Author(s):

E. D. Doss ◽

M. G. Srinivasan

Keyword(s):

Shear Stress ◽

Flow Model ◽

Flow Characteristics ◽

Wall Friction ◽

Gas Flows ◽

Two Phase ◽

One Dimensional ◽

Friction Models ◽

Wall Interaction ◽

The One

The empirical expressions for the equivalent friction factor to simulate the effect of particle-wall interaction with a single solid species have been extended to model the wall shear stress for multispecies solid-gas flows. Expressions representing the equivalent shear stress for solid-gas flows obtained from these wall friction models are included in the one-dimensional two-phase flow model and it can be used to study the effect of particle-wall interaction on the flow characteristics.

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A flame-wall interaction model for combustion and heat transfer in S.I. engines

Heat Transfer - Japanese Research ◽

10.1002/(sici)1520-6556(1998)27:3<205::aid-htj3>3.0.co;2-z ◽

1998 ◽

Vol 27 (3) ◽

pp. 205-215

Author(s):

Kazuie Nishiwaki ◽

Takafumi Kojima

Keyword(s):

Heat Transfer ◽

Interaction Model ◽

Wall Interaction

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Multiscale Study of Gas Slip Flows in Nanochannels

Journal of Heat Transfer ◽

10.1115/1.4030205 ◽

2015 ◽

Vol 137 (9) ◽

Cited By ~ 4

Author(s):

Quy Dong To ◽

Thanh Tung Pham ◽

Vincent Brites ◽

Céline Léonard ◽

Guy Lauriat

Keyword(s):

Density Functional ◽

Interaction Model ◽

Maxwell Model ◽

Theoretical Models ◽

Md Simulations ◽

Gas Flows ◽

Simulation And Modeling ◽

Slip Effects ◽

Accommodation Coefficients ◽

Ar Gas

A multiscale modeling of the anisotropic slip phenomenon for gas flows is presented in a tree-step approach: determination of the gas–wall potential, simulation and modeling of the gas–wall collisions, simulation and modeling of the anisotropic slip effects. The density functional theory (DFT) is used to examine the interaction between the Pt–Ar gas–wall couple. This potential is then passed into molecular dynamics (MD) simulations of beam scattering experiments in order to calculate accommodation coefficients. These coefficients enter in an effective gas–wall interaction model, which is the base of efficient MD simulations of gas flows between anisotropic surfaces. The slip effects are quantified numerically and compared with simplified theoretical models derived in this paper. The paper demonstrates that the DFT potential is in good agreement with empirical potentials and that an extension of the Maxwell model can describe anisotropic slip effects due to surface roughness, provided that two tangential accommodation parameters are introduced. MD data show excellent agreement with the tensorial slip theory, except at large Kundsen numbers (for example, Kn ≃0.2) and with an analytical expression which predicts the ratio between transverse and longitudinal slip velocity components.

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