Experimental measurement on tangential momentum accommodation coefficient in a single microtube

Yamaguchi, Hiroki; Hanawa, Tsuneo; Yamamoto, Oto; Matsuda, Yu; Egami, Yasuhiro; Niimi, Tomohide

doi:10.1007/s10404-011-0773-x

Cited by 66 publications

(23 citation statements)

References 21 publications

(36 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is found that the simulated plenum pressure matches the experimental plenum pressure only when a slip boundary condition is used with the recommended value of α u = 0.9 for both N 2 and Ar [38][39][40][41][42][43][44][45][46]. The plenum pressure is very slightly overestimated with a no-slip boundary condition, and FIGURE 3 | Experimental plenum pressure (blue line) and chamber pressure (black line) measurements against mass flow rate of Ar into PR.…”

Section: Set 1: Pr Laboratory Conditionmentioning

confidence: 91%

“…Measurements of α u are typically performed by tracking the flow of gas through a microchannel. These experiments [38][39][40][41][42][43][44][45][46] are performed over a wide range of pressures at room temperature, and use microchannels with different shapes and diameters, constructed of various materials and surface treatments. Since the α u of each gas remains roughly constant across different conditions and flow regimes, it is justified to use the mean value of α u for each gas in the simulations.…”

Section: Simulation Parametersmentioning

confidence: 99%

See 1 more Smart Citation

A Comprehensive Cold Gas Performance Study of the Pocket Rocket Radiofrequency Electrothermal Microthruster

Charles

Boswell

2017

Front. Phys.

View full text Add to dashboard Cite

This paper presents computational fluid dynamics simulations of the cold gas operation of Pocket Rocket and Mini Pocket Rocket radiofrequency electrothermal microthrusters, replicating experiments performed in both sub-Torr and vacuum environments. This work takes advantage of flow velocity choking to circumvent the invalidity of modeling vacuum regions within a CFD simulation, while still preserving the accuracy of the desired results in the internal regions of the microthrusters. Simulated results of the plenum stagnation pressure is in precise agreement with experimental measurements when slip boundary conditions with the correct tangential momentum accommodation coefficients for each gas are used. Thrust and specific impulse is calculated by integrating the flow profiles at the exit of the microthrusters, and are in good agreement with experimental pendulum thrust balance measurements and theoretical expectations. For low thrust conditions where experimental instruments are not sufficiently sensitive, these cold gas simulations provide additional data points against which experimental results can be verified and extrapolated. The cold gas simulations presented in this paper will be used as a benchmark to compare with future plasma simulations of the Pocket Rocket microthruster.

show abstract

Section: Set 1: Pr Laboratory Conditionmentioning

confidence: 91%

Section: Simulation Parametersmentioning

confidence: 99%

A Comprehensive Cold Gas Performance Study of the Pocket Rocket Radiofrequency Electrothermal Microthruster

Charles

Boswell

2017

Front. Phys.

View full text Add to dashboard Cite

show abstract

“…To check the fraction of each component and other residual gases, the gas in the downstream chamber was sampled through a variable leak valve and analyzed by a quadrupole mass spectrometer (Pfeiffer Vacuum, QMS 200) with a pumping station before and after each measurement of the mass flow rate. Due to the connection to the QMS, the volume of the downstream chamber was a little increased from the previously reported value 15) to Vo [cm 3 ] = 450.26 +0.017…”

Section: A Experimental Proceduresmentioning

confidence: 83%

“…The measurement principle and setup is explained in details in Ref. 15 and a schematic of the setup is shown in Fig. 1.…”

Section: A Experimental Proceduresmentioning

confidence: 99%

See 1 more Smart Citation

Viscous slip coefficients for binary gas mixtures measured from mass flow rates through a single microtube

et al. 2016

View full text Add to dashboard Cite

The viscous slip coefficient for helium-argon binary gas mixture is extracted from the experimental values of the mass flow rate through a microtube. The mass flow rate is measured by the constant-volume method. The viscous slip coefficient was obtained by identifying the measured mass flow rate through a microtube with the corresponding analytical expression, which is a function of the Knudsen number. The measurements were carried out in the slip flow regime where the first-order slip boundary condition can be applied. The measured viscous slip coefficients of binary gas mixtures exhibit a concave function of the molar ratio of the mixture, showing a similar profile with numerical results. However, from the detailed comparison between the measured and numerical values with the complete and incomplete accommodation at a surface, it is inappropriate to estimate the viscous slip coefficient for the mixture numerically by employing separately measured tangential momentum accommodation coefficient for each component. The time variation of the molar ratio in the downstream chamber was measured by sampling the gas from the chamber using the quadrupole mass spectrometer. In our measurements, it is indicated that the volume flow rate of argon is larger than that of helium because of the difference in the tangential momentum accommodation coefficient.

show abstract

An analytical model for real gas flow in shale nanopores with non‐circular cross‐section

Ren

Tian

et al. 2016

AIChE Journal

View full text Add to dashboard Cite

An analytical model for gas transport in shale media is proposed on the basis of the linear superposition of convective flow and Knudsen diffusion, which is free of tangential momentum accommodation coefficient. The present model takes into the effect of pore shape and real gas, and is successfully validated against experimental data and Lattice-Boltzmann simulation results. Gas flow in noncircular nanopores can be accounted by a dimensionless geometry correction factor. In continuum-flow regime, pore shape has a relatively minor impact on gas transport capacity; the effect of pore shape on gas transport capacity enhances significantly with increasing rarefaction. Additionally, gas transport capacity is strongly dependent of average pore size and streamline tortuosity. We also show that the present model without using weighted factor can describe the variable contribution of convective flow and Knudsen diffusion to the total flow. As pressure and pore radius decrease, the number of molecule-wall collisions gradually predominates over the number of intermolecule collisions, and thus Knudsen diffusion contributes more to the total flow. The parameters in the present model can be determined from independent laboratory experiments. We have the confidence that the present model can provide some theoretical support in numerical simulation of shale gas production.Where a is the geometry correction factor, dimensionless, with a 5 1 for a circular; r e is equivalent pore radius, m.

show abstract

Experimental measurement on tangential momentum accommodation coefficient in a single microtube

Cited by 66 publications

References 21 publications

A Comprehensive Cold Gas Performance Study of the Pocket Rocket Radiofrequency Electrothermal Microthruster

A Comprehensive Cold Gas Performance Study of the Pocket Rocket Radiofrequency Electrothermal Microthruster

Viscous slip coefficients for binary gas mixtures measured from mass flow rates through a single microtube

An analytical model for real gas flow in shale nanopores with non‐circular cross‐section

Contact Info

Product

Resources

About