Sharp Asymptotics for KPP Pulsating Front Speed-Up and Diffusion Enhancement by Flows

During atmospheric (re-)entries, planetary probes encounter huge heat fluxes due to their significant speed (up to 13 km/s for an Earth re-entry). The total heat flux received by the probe can be divided into two main components: a convective one (coming from the conduction and diffusion phenomena occuring in the shock layer) and a radiative one (due to the radiation of certain species). Numerical simulations have been performed for both Titan (Huygens mission) and Earth (Fire II mission) entries. The main parameters influencing the results are the atmosphere composition, the chemical reaction scheme, the transport model and the radiative model. The results obtained gave us information on the flowfield (temperature, pressure, species densities...) and values for the heat fluxes on the wall that are useful for experimental or flight data comparison.

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Erratum: “Multiple current reversals and diffusion enhancement in a symmetrical periodic potential” [Chaos 22, 033125 (2012)]

Chaos An Interdisciplinary Journal of Nonlinear Science ◽

10.1063/1.4751342 ◽

2012 ◽

Vol 22 (3) ◽

pp. 039901 ◽

Cited By ~ 6

Author(s):

Chunhua Zeng ◽

Hua Wang ◽

Linru Nie

Keyword(s):

Periodic Potential ◽

Diffusion Enhancement ◽

And Diffusion

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Multiple current reversals and diffusion enhancement in a symmetrical periodic potential

Chaos An Interdisciplinary Journal of Nonlinear Science ◽

10.1063/1.4745853 ◽

2012 ◽

Vol 22 (3) ◽

pp. 033125 ◽

Cited By ~ 21

Author(s):

Chunhua Zeng ◽

Hua Wang ◽

Linru Nie

Keyword(s):

Periodic Potential ◽

Diffusion Enhancement ◽

And Diffusion

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trans-Sodium Crocetinate and Diffusion Enhancement

The Journal of Physical Chemistry B ◽

10.1021/jp064308+ ◽

2006 ◽

Vol 110 (37) ◽

pp. 18078-18080 ◽

Cited By ~ 13

Author(s):

Amanda K. Stennett ◽

Gail L. Dempsey ◽

John L. Gainer

Keyword(s):

Diffusion Enhancement ◽

And Diffusion

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Dramatic Speed-Up in FEM Simulations of Various Incremental Forming Processes Thanks to Multi-Mesh Implementation in Forge®

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.554-557.2499 ◽

2013 ◽

Vol 554-557 ◽

pp. 2499-2506

Author(s):

Pascal De Micheli ◽

Etienne Perchat ◽

Richard Ducloux ◽

Hugues Digonnet ◽

Lionel Fourment

Keyword(s):

Parallel Computing ◽

Metal Forming ◽

Incremental Forming ◽

Fem Simulations ◽

Adaptive Remeshing ◽

Wide Range ◽

Speed Up ◽

Forming Simulations ◽

And Diffusion ◽

Dual Mesh

Improvements in parallel computing and adaptive remeshing have permitted to simulate a wide range of metal forming processes within few hours or days on modern multi-core workstations. However, they do not tackle the issues encountered in incremental forming processes, making them very challenging. Multi-mesh methods opens very interesting doors in this domain, making possible to take advantage of adaptive remeshing techniques (optimizing the ratio precision/cost) without its usual drawbacks (loss of information and diffusion issues).We present in this article a fully parallel Dual-Mesh implementation in the commercial FEA software FORGE®, compatible with a wide range of other FEM facilities. Speed-up larger than 4 are common for incremental forming simulations, and speed-up larger than 10 can be reached in favorable cases. Parallel efficiency is the same than for our standard computations (>80% for more than 2000 nodes per core).

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