Plasma formation in ambient fluid from hypervelocity impacts

Islam, Shafquat T.; Ma, Wentao; Michopoulos, John G.; Wang, Kevin

doi:10.1016/j.eml.2022.101927

Cited by 8 publications

(7 citation statements)

References 41 publications

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“…4. Nonetheless, the algorithms presented in this paper are designed to be applicable to general equations of state in the form of (5).…”

Section: Navier-stokes Equations With General Equations Of Statementioning

confidence: 99%

“…Nonetheless, when exact Riemann problems are constructed and solved in 2D and 3D multi-material simulations, manually specifying an integration step size for each Riemann problem is impossible. A common practice is to specify a fixed number of integration steps for all the exact Riemann problems constructed throughout the simulation (e.g., [24,1,5]). Clearly, this is not optimal from both accuracy and efficiency standpoints.…”

Section: Adaptive Step Sizementioning

confidence: 99%

“…Finally, we consider an example problem of hypervelocity impact, first presented in [5]. This problem features a copper projectile impacting onto a soda lime glass (SLG) target in a neon gas environment.…”

Section: Hypervelocity Impactmentioning

confidence: 99%

“…Many fluid dynamics problems involving bubbles, droplets, phase transitions, and chemical reactions fall into this category (e.g., [1,2,3]). Some problems in solid and soft matter mechanics also belong to this category, when the material behaves like a compressible fluid due to some special loading condition (e.g., [4,5]). Because of compressibility, the physical model typically involves a thermodynamic equation of state (EOS) for each material.…”

Section: Introductionmentioning

confidence: 99%

“…Recently, Farhat et al developed the FIVER (FInite Volume method with Exact multiphase Riemann solvers) method, in which the exact solutions of bimaterial Riemann problems are used directly to compute advective fluxes, instead of populating ghost or real fluid cells [23,24,27,28,29]. FIVER has been applied to study several shock-dominated multiphase flow and fluid-structure interaction problems, including underwater explosion and implosion [30,31], pipeline explosion [27], cavitation erosion [32,33,34,35], laser-induced vaporization [1], and hypervelocity impact [5]. Furthermore, some authors have proposed to extend exact Riemann problem solvers to account for additional interfacial physics, such as surface tension and phase transition [25,3,26].…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Efficient Solution of Bimaterial Riemann Problems for Compressible Multi-Material Flow Simulations

Ma¹,

Zhao²,

Islam³

et al. 2023

Preprint

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When solving compressible multi-material flow problems, an unresolved challenge is the computation of advective fluxes across material interfaces that separate drastically different thermodynamic states and relations. A popular idea in this regard is to locally construct bimaterial Riemann problems, and to apply their exact solutions in flux computation. For general equations of state, however, finding the exact solution of a Riemann problem is expensive as it requires nested loops. Multiplied by the large number of Riemann problems constructed during a simulation, the computational cost often becomes prohibitive. The work presented in this paper aims to accelerate the solution of bimaterial Riemann problems without introducing approximations or offline precomputation tasks. The basic idea is to exploit some special properties of the Riemann problem equations, and to recycle previous solutions as much as possible. Following this idea, four acceleration methods are developed, including (1) a change of integration variable through rarefaction fans, (2) storing and reusing integration trajectory data, (3) step size adaptation, and (4) constructing an R-tree on the fly to generate initial guesses. The performance of these acceleration methods are assessed using four example problems in underwater explosion, laser-induced cavitation, and hypervelocity impact. These problems exhibit strong shock waves, large interface deformation, contact of multiple (> 2) interfaces, and interaction between gases and condensed matters. For all the problems, the acceleration methods are able to significantly reduce the computational cost without affecting solver robustness or solution accuracy. In different cases, the solution of bimaterial Riemann problems is accelerated by 37 to 83 times. As a result, the total cost of advective flux computation, which includes the exact Riemann problem solution at material interfaces and the numerical flux calculation over the entire computational domain, is accelerated by 18 to 79 times.

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“…4. Nonetheless, the algorithms presented in this paper are designed to be applicable to general equations of state in the form of (5).…”

Section: Navier-stokes Equations With General Equations Of Statementioning

confidence: 99%

Section: Adaptive Step Sizementioning

confidence: 99%

Section: Hypervelocity Impactmentioning

confidence: 99%