Monte Carlo modeling of electron density in hypersonic rarefied gas flows

Fan, Jin Yun; Zhang, Yuhuai; Jiang, Jingjie

doi:10.1063/1.4902586

Cited by 5 publications

(5 citation statements)

References 8 publications

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“…Comparing with that in Ref. [40], where a DELL cluster with 64 processors was used and 20 h of CPU time was consumed, the present proposed model and the developed code can be said to be highly Fig. 8 The NO + number density per m 3 for RAM-C II at 81 km Fig.…”

Section: Ionization Reactions For the Ram-c II At 81 Kmmentioning

confidence: 69%

“…[40] is 2D computation, and the present computation is 3D with different CPU time, in which the total number of simulated particles in the present case is about 5 × 10 7 , while that in Ref. [40] is 10 7 .…”

Section: Ionization Reactions For the Ram-c II At 81 Kmmentioning

confidence: 71%

“…The RAM-C (Radio-Wave Attenuation Measurement for Study of Communication Blackout) II flight experiment [44,55] performed in the late 1960s provides unique experimental data to study ionization in rarefied atmosphere, which is usually used as a classical benchmark case to verify computational models [40][41][42]. The entry speed of the RAM-C II vehicle is 7.8 km/s, and its configuration and the probe locations are illustrated in Fig.…”

Section: Ionization Reactions For the Ram-c II At 81 Kmmentioning

confidence: 99%

“…Also using axisymmetric configuration, Boyd [39] applied DSMC to study the rarefied ionization of RAMC-II and introduced a special numerical scheme to trace species and electron-ion enforced association. Fan [40] proposed a trace species separation (TSS) scheme to compute the electron density distribution around the RAMC-II which was also simplified to an axisymmetric configuration. Unlike the probabilistic models of traditional DSMC, TTS calculates the particle number densities of trace species from those of common species based on reaction rates.…”

Section: Introductionmentioning

confidence: 99%

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DSMC modeling of rarefied ionization reactions and applications to hypervelocity spacecraft reentry flows

Fang

Liang

et al. 2020

Adv. Aerodyn.

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The DSMC modeling is developed to simulate three-dimensional (3D) rarefied ionization flows and numerically forecast the communication blackout around spacecraft during hypervelocity reentry. A new weighting factor scheme for rare species is introduced, whose key point is to modify the corresponding chemical reaction coefficients involving electrons, meanwhile reproduce the rare species in resultants and preserve/delete common species in reactants according to the weighting factors. The resulting DSMC method is highly efficient in simulating weakly inhomogeneous flows including the Couette shear flow and controlling statistical fluctuation with high resolution. The accurate reliability of the present DSMC modeling is also validated by the comparison with a series of experimental measurements of the Shenzhou reentry capsule tested in a low-density wind tunnel from the HAI of CARDC. The obtained electron number density distribution for the RAM-C II vehicle agrees well with the flight experiment data, while the electron density contours for the Stardust hypervelocity reentry match the reference data completely. In addition, the present 3D DSMC algorithm can capture distribution of the electron, N + and O + number densities better than the axis-symmetric DSMC model. The introduction of rare species weighting factor scheme can significantly improve the smoothness of the number density contours of rare species, especially for that of electron in weak ionization case, while it has negligible effect on the macroscopic flow parameters. The ionization characteristics of the Chinese lunar capsule reentry process are numerically analyzed and forecasted in the rarefied transitional flow regime at the flying altitudes between 80 and 97 km, and the simulations predict communication blackout altitudes which are in good agreement with the actual reentry flight data. For the spacecraft reentry with hypervelocity larger than the second cosmic speed, it is forecasted and verified by the present DSMC modeling that ionization reactions will cover the windward capsule surface, leading to reentry communication blackout, and the communication interruption must be considered in the communication design during reentry in rarefied flow regimes.

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Section: Ionization Reactions For the Ram-c II At 81 Kmmentioning

confidence: 69%

Section: Ionization Reactions For the Ram-c II At 81 Kmmentioning

confidence: 71%

Section: Ionization Reactions For the Ram-c II At 81 Kmmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

DSMC modeling of rarefied ionization reactions and applications to hypervelocity spacecraft reentry flows

Fang

Liang

et al. 2020

Adv. Aerodyn.

View full text Add to dashboard Cite

show abstract

“…It should be noted that the number densities of primary species are obtained through a sampling and averaging in the first round of the TSS algorithm, while the number densities of trace species are updated each time step in the second round of TSS until they reach a steady state. More details see [17].…”

Section: Methodsmentioning

confidence: 99%