### Abstract

Language | English |
---|---|

Title of host publication | Proceedings of the 8th International Conference on Nanochannels, Microchannels and Minichannels 2010 |

Subtitle of host publication | parts a & b |

Place of Publication | New York |

Pages | 481-490 |

Number of pages | 10 |

Publication status | Published - 2011 |

### Fingerprint

### Keywords

- knudsen layer
- molecules
- models
- transition regime
- thermal transpiration
- importance
- mean free path
- determine
- gas micro flow behaviour

### Cite this

*Proceedings of the 8th International Conference on Nanochannels, Microchannels and Minichannels 2010: parts a & b*(pp. 481-490). New York.

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*Proceedings of the 8th International Conference on Nanochannels, Microchannels and Minichannels 2010: parts a & b.*New York, pp. 481-490.

**The importance of mean free path in determining gas micro flow behaviour.** / Dongari, Nishanth; Zhang, Yonghao; Reese, Jason.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution book

TY - GEN

T1 - The importance of mean free path in determining gas micro flow behaviour

AU - Dongari, Nishanth

AU - Zhang, Yonghao

AU - Reese, Jason

PY - 2011

Y1 - 2011

N2 - We investigate whether a power-law form of probability distribution function better describes the free paths of dilute gas molecules in a confined system. An effective molecular mean free path model is derived, which allows the mean free path to vary close to bounding surfaces. Our model is compared with molecular dynamics simulation data, and also other classical mean free path models. As gas transport properties can be related to the mean free path through kinetic theory, the Navier-Stokes constitutive relations are then modified and applied to various benchmark test cases. Results for isothermal pressure-driven Poiseuille flows in micro-channels are reported, and we compare our results with conventional hydrodynamic models, solutions of the Boltzmann equation, and experimental data. Our new approach provides good results for mean free path and cross-sectional flow velocity profiles up to Knudsen numbers around 1, and for integral flow parameters such as flow rate and friction factor up to Knudsen number of 10. We discuss some limitations of our power-law model, and point to the way forward for further development.

AB - We investigate whether a power-law form of probability distribution function better describes the free paths of dilute gas molecules in a confined system. An effective molecular mean free path model is derived, which allows the mean free path to vary close to bounding surfaces. Our model is compared with molecular dynamics simulation data, and also other classical mean free path models. As gas transport properties can be related to the mean free path through kinetic theory, the Navier-Stokes constitutive relations are then modified and applied to various benchmark test cases. Results for isothermal pressure-driven Poiseuille flows in micro-channels are reported, and we compare our results with conventional hydrodynamic models, solutions of the Boltzmann equation, and experimental data. Our new approach provides good results for mean free path and cross-sectional flow velocity profiles up to Knudsen numbers around 1, and for integral flow parameters such as flow rate and friction factor up to Knudsen number of 10. We discuss some limitations of our power-law model, and point to the way forward for further development.

KW - knudsen layer

KW - molecules

KW - models

KW - transition regime

KW - thermal transpiration

KW - importance

KW - mean free path

KW - determine

KW - gas micro flow behaviour

M3 - Conference contribution book

SN - 9780791854501

SP - 481

EP - 490

BT - Proceedings of the 8th International Conference on Nanochannels, Microchannels and Minichannels 2010

CY - New York

ER -