Surface Roughness Effects in Low Reynolds Number Channel Flows

Gimelsheim, N.; Duncan, J.; Lilly, Taylor; Gimelshein, S. F.; Ketsdever, Andrew D.; Wysong, Ingrid J.

doi:10.21236/ada454769

Cited by 4 publications

(3 citation statements)

References 12 publications

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“…Extensive experimental study has been performed [1,2] and it requires a very accurate flow rate measurements and definition of surface shape. Numerical study is relatively easier and provides more detailed information about the flow properties.…”

Section: Introductionmentioning

confidence: 99%

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Statistical Simulation of Gas Flows through Short Rough Microchannels

Markelov¹,

Stefanov²

2011

AIP Conference Proceedings

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Rarefied gas flow though the rough microchannel is modeled using the direct simulation Monte Carlo method (DSMC). Deterministic and statistical methods of wall roughness deception have been applied. The well-known DSMC-based software, SMILE, allows one to model a flow through the channel with an arbitrary shape, here series of triangular obstacles has been modeled. A statistical approach is based on porous layer model of dusty gas and the model has been implemented in SMILE. Results obtained with two methods are compared and channel performance is presented for different pressure ratio and size of obstacles.

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Section: Introductionmentioning

confidence: 99%

“…A number of statistical models of the wall roughness such as randomly distributed conical surfaces, periodically corrugated channel surface etc. was proposed in [6,2,7,8,9]. Other example of the statistical model is an application of porous media model for rough microchannels [10].…”

Section: Introductionmentioning

confidence: 99%

Statistical Simulation of Gas Flows through Short Rough Microchannels

Markelov¹,

Stefanov²

2011

AIP Conference Proceedings

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“…The development of methods of computer modeling and the use of new experimental technologies, in particular, scanning probe microscopy, allow certain progress to be achieved in numerical simulations of gas scattering on rough surfaces and in the description of rarefied gas flows in channels with the surface structure corresponding to conditions of physical experiments [5][6][7].…”

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confidence: 99%

Numerical simulations of gas-dynamic conductivity of microchannels with allowance for their surface structure

Ukhov¹,

Porodnov²,

Borisov

2009

J Appl Mech Tech Phy

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The effect of the microchannel surface structure on the free-molecular gas flow is studied by the testparticle method. Simulations are performed for channels whose surface either is obtained by means of statistical modeling or is reconstructed from the data of atomic-force microscopy of real surfaces. Dependences of monochromatic molecular beam scattering on the angle of incidence and the average height of microscopic roughness elements on the surface are considered. It is demonstrated that the method developed allows one to obtain the distribution function for particles reflected from a rough surface and to use it in the boundary conditions in problems of rarefied gas dynamics.Key words: rarefied gas flow in microchannels, Monte Carlo test-particle method, gas-surface interaction, scattering indicatrices, atomic-force microscopy.Introduction. In solving gas-dynamic problems associated with re-entry of flying vehicles into the upper atmospheric layers or with gas flows in microscale or nanoscale devices, one should take into account the parameters characterizing the structure and chemical composition of the surface. Numerous experimental studies show that the surface structure, its temperature, and other factors exert a significant effect on scattering of rarefied gas molecules and, as a consequence, on the gas-dynamic drag and heat transfer in the gas-solid system [1].One important component of the model of gas dynamics in external and internal flows are the boundary conditions for the Boltzmann equation, which imply that the distribution function of gas molecules reflected from the surface is available in an analytical form. This function depends on many characteristics of the gas and the surface, and also on thermodynamic parameters of the system as a whole. One factor exerting a significant effect on energy and momentum transfer in the gas-solid system is physical inhomogeneity (roughness) of the surface.Because of the lack of information about the surface structure and its role in gas-solid interaction, approaches with the use of absolutely smooth surfaces or extremely simple roughness models are usually used [2]. The influence of the surface structure on the free-molecular gas flow in cylindrical channels was studied in experiments [3,4].The development of methods of computer modeling and the use of new experimental technologies, in particular, scanning probe microscopy, allow certain progress to be achieved in numerical simulations of gas scattering on rough surfaces and in the description of rarefied gas flows in channels with the surface structure corresponding to conditions of physical experiments [5][6][7].The use of atomic force microscopy allows one to obtain high-resolution three-dimensional topograms. The thus-obtained digitized surface is an array whose elements contain the coordinates of each point of the surface of the examined sample. In the present work, we used the coordinates of 160 thousand points on the surface of a 20 × 20 μm silicon single crystal. In the course of studying the specified...

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Analytic model of the effect of poly-Gaussian roughness on rarefied gas flow near the surface

Aksenova¹,

Khalidov²

2016

AIP Conference Proceedings

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Surface Roughness Effects in Low Reynolds Number Channel Flows

Cited by 4 publications

References 12 publications

Statistical Simulation of Gas Flows through Short Rough Microchannels

Statistical Simulation of Gas Flows through Short Rough Microchannels

Numerical simulations of gas-dynamic conductivity of microchannels with allowance for their surface structure

Analytic model of the effect of poly-Gaussian roughness on rarefied gas flow near the surface

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