Nonequilibrium flow through porous thermal protection materials, Part I: Numerical methods

Stern, Eric C.; Poovathingal, Savio J.; Nompelis, Ioannis; Schwartzentruber, Thomas E.; Candler, Graham V.

doi:10.1016/j.jcp.2017.09.011

Cited by 48 publications

(14 citation statements)

References 30 publications

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“…Both approaches are briefly discussed in this section. A more detailed description of the code layouts, efficiency considerations, and coupling strategies can be found in previous publications [24,25].…”

Section: Methodsmentioning

confidence: 99%

“…Several details of the Fibergen code along with the algorithm, code layout and architecture have been described before and is available in Ref. 25. Two new features have been added to Fibergen which are described below.…”

Section: Fibergen: a Synthetic Microstructure Generating Codementioning

confidence: 99%

“…Effective permeability of FiberForm has been computationally obtained by various groups [21][22][23][24][25][26]. Borner et al [21], White et al [22], and Jambunathan et al [23] used direct simulation Monte Carlo (DSMC) as the flow solver while Ho et al [26,27] used Lattice Boltzmann as the flow solver.…”

Section: Introductionmentioning

confidence: 99%

“…Since XRCT images were obtained only for a few samples, it limits the validation efforts with experiments and the ability to explore the material parameter space that influences effective permeability. Stern et al [25] developed a synthetic microstructure generating code called Fibergen to reproduce the microstructure of FiberForm.…”

Section: Introductionmentioning

confidence: 99%

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Computation of Effective Permeability for Porous Carbon Composites

Poovathingal¹,

Soto²,

Brewer³

2021

Preprint

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Effective permeability of a porous carbon composite is computed using the direct simulation Monte Carlo technique. The microstructure of the carbon composite is synthetically generated using an in-house solver. Permeabilities obtained using synthetic microstructures of the precursor (carbon fibers) is compared to two independent experimental dataset and good agreement is observed. An approach to digitally infuse matrix into the precursor is proposed. Comparison of the permeability for the full composite (carbon fibers with matrix) with experimental data demonstrates good agreement indicating that representative microstructures generated digitally can be used to compute and predict effective permeability of porous carbon composites. Simulations of gases penetrating the full composite are performed, and an intrinsic material permeability (Ko) of 11.866 × 10−11 m2, and a Klinkenberg constant (b∗) of 5.655 × 10−8 that is only dependent on the temperature and the molecular weight of the gaseous species is obtained.

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Section: Methodsmentioning

confidence: 99%

Section: Fibergen: a Synthetic Microstructure Generating Codementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Computation of Effective Permeability for Porous Carbon Composites

Poovathingal¹,

Soto²,

Brewer³

2021

Preprint

Self Cite

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“…Common applications include satellites [16], reentry vehicles [17], and microelectromechanical systems [18]. A number of studies have used DSMC to study subsonic flows through channels or porous materials [19][20][21][22][23][24][25][26][27][28]. Fewer studies have investigated subsonic, external aerodynamic flows around a body [12,[29][30][31].…”

Section: Gasmentioning

confidence: 99%

Low-Speed DSMC Simulations of Hotwire Anemometers at High-Altitude Conditions

Roseman

Argrow

2021

Fluids

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Numerical simulations of hotwire anemometers in low-speed, high-altitude conditions have been carried out using the direct simulation Monte Carlo (DSMC) method. Hotwire instruments are commonly used for in-situ turbulence measurements because of their ability to obtain high spatial and temporal resolution data. Fast time responses are achieved by the wires having small diameters (1–5 μm). Hotwire instruments are currently being used to make in-situ measurements of high-altitude turbulence (20–40 km). At these altitudes, hotwires experience Knudsen number values that lie in the transition-regime between slip-flow and free-molecular flow. This article expands the current knowledge of hotwire anemometers by investigating their behavior in the transition-regime. Challenges involved with simulating hotwires at high Knudsen number and low Reynolds number conditions are discussed. The ability of the DSMC method to simulate hotwires from the free-molecular to slip-flow regimes is demonstrated. Dependence of heat transfer on surface accommodation coefficient is explored and discussed. Simulation results of Nusselt number dependence on Reynolds number show good agreement with experimental data. Magnitude discrepancies are attributed to differences between simulation and experimental conditions, while discrepancies in trend are attributed to finite simulation domain size.

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