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Knudsen number

About: Knudsen number is a research topic. Over the lifetime, 5052 publications have been published within this topic receiving 104278 citations.


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Journal ArticleDOI
TL;DR: In this article, a review of the theory and measurements of transport processes between small particles and the surrounding gas is provided, and a growing body of evidence that accommodation coefficients are of order unity in many cases, but coefficients smaller than 0.01 are still reported.

75 citations

Journal ArticleDOI
TL;DR: In this article, a fully predictive mathematical model was developed for membrane distillation considering heat and mass transfers and concentration polarisation, and the effect of parameters such as thickness of cavity, temperature and feed flow rate were investigated.

75 citations

Journal ArticleDOI
TL;DR: In this paper, the authors discuss some approximate methods which have been used to calculate aerodynamic heating rates on high-speed vehicles, including the stagnation point and leading edges, axisymmetric analog, laminar and turbulent heating rate, transition heating rates, gas models, and three-dimensional applications.
Abstract: It is pointed out that preliminary design and optimization studies for new aerospace vehicles require techniques which can calculate aerodynamic heating rates accurately and efficiently. The method employed to calculate the flow field depends to a large extent on the shape of the vehicle, Mach number, Reynolds number, and Knudsen number. In the case of the aero-assisted orbital transfer vehicle (AOTV), a substantial portion of the flight will be in the transitional regime between continuum and free molecule flow. The present paper discusses some approximate methods which have been used to calculate heating rates on high-speed vehicles. Attention is given to the stagnation point and leading edges, the downstream region, the axisymmetric analog, laminar and turbulent heating rates, transition heating rates, gas models, and three-dimensional applications.

75 citations

Journal ArticleDOI
TL;DR: In this article, an efficient Monte Carlo (MC) method on the basis of introducing a model of phonon scattering processes is proposed to simulate the ballistic-diffusive heat conduction in silicon nanofilms.

75 citations

Journal ArticleDOI
TL;DR: In this paper, the porosity, mean pore size, and standard deviation of the pore sizes were measured for both the Knudsen and ordinary diffusion regimes to predict diffusion rates.
Abstract: Porous solids have been simulated in the computer as assemblages of spheres. When such assemblages contain spheres distributed in size and randomly arranged in space, the structure of the resulting solid resembles that of a real porous solid. Monte Carlo calculations of gas molecule trajectories through the assemblages were carried out for both the Knudsen and ordinary diffusion regimes. Tortuosities calculated from the simulated diffusion “data” fell in the range obtained experimentally by other investigators. Correlations were obtained that enable the prediction of diffusion rates from measurement of the porosity, mean pore size, and standard deviation of the pore size.

75 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023112
2022236
2021168
2020163
2019190
2018172