The Coupling of Radiation and Hydrodynamics

Lowrie, Robert B.; Morel, Jim E.; Hittinger, Jeffrey

doi:10.1086/307515

Cited by 179 publications

(169 citation statements)

References 17 publications

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“…Following Lowrie et al (1999) and JSD12, we solve the RT equation in the mixed frame: the specific intensity is measured in an Eulerian frame while the radiation-material interaction terms are computed in the co-moving frame of the fluid. This requires a Lorentz transformation of variables between frames.…”

Section: Equationsmentioning

confidence: 99%

“…The time-and velocity-dependent terms in Equation (1) change significantly the algorithm for solving the RT equation compared with the short characteristic method described in Davis et al (2012). In order to couple the radiation field to the gas, we need to take the angular moments of Equation (1) to get the radiation energy (S r (E)) and momentum (S r ( P)) source terms (these are easily confirmed to be exactly the same as in Lowrie et al (1999) and JSD12). The zeroth and first moments of the right-hand side of equation (1) multiplied by 4π/c are…”

Section: Equationsmentioning

confidence: 99%

“…We adopt an equation of state for an ideal gas with adiabatic index γ , thus E g = P /(γ − 1) for γ = 1 and T = P /R ideal ρ, where R ideal is the ideal gas constant. In order to get a better insight on the relative importance of different terms in the radiation MHD equations, following Lowrie et al (1999) and JSD12, we convert the above equations into dimensionless form by adopting two ratios C = c/a 0 and P = a r T 4 0 /P 0 , where a 0 , T 0 and P 0 are the characteristic values of velocity, temperature, and gas pressure, respectively. Therefore, C is the dimensionless speed of light while P is a measure of relative importance between radiation pressure and gas pressure when gas temperature is around T 0 .…”

Section: Equationsmentioning

confidence: 99%

See 2 more Smart Citations

An Algorithm for Radiation Magnetohydrodynamics Based on Solving the Time-Dependent Transfer Equation

Jiang¹,

Stone²,

Davis³

2014

ApJS

102

131

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We describe a new algorithm for solving the coupled frequency-integrated transfer equation and the equations of magnetohydrodynamics in the regime that light-crossing time is only marginally shorter than dynamical timescales. The transfer equation is solved in the mixed frame, including velocity-dependent source terms accurate to O(v/c). An operator split approach is used to compute the specific intensity along discrete rays, with upwind monotonic interpolation used along each ray to update the transport terms, and implicit methods used to compute the scattering and absorption source terms. Conservative differencing is used for the transport terms, which ensures the specific intensity (as well as energy and momentum) are conserved along each ray to round-off error. The use of implicit methods for the source terms ensures the method is stable even if the source terms are very stiff. To couple the solution of the transfer equation to the MHD algorithms in the Athena code, we perform direct quadrature of the specific intensity over angles to compute the energy and momentum source terms. We present the results of a variety of tests of the method, such as calculating the structure of a non-LTE atmosphere, an advective diffusion test, linear wave convergence tests, and the well-known shadow test. We use new semi-analytic solutions for radiation modified shocks to demonstrate the ability of our algorithm to capture the effects of an anisotropic radiation field accurately. Since the method uses explicit differencing of the spatial operators, it shows excellent weak scaling on parallel computers.

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Section: Equationsmentioning

confidence: 99%

Section: Equationsmentioning

confidence: 99%

Section: Equationsmentioning

confidence: 99%

See 1 more Smart Citation

An Algorithm for Radiation Magnetohydrodynamics Based on Solving the Time-Dependent Transfer Equation

Jiang¹,

Stone²,

Davis³

2014

ApJS

102

131

View full text Add to dashboard Cite

show abstract

“…Le système (2), (3), (4) (et sa version non barotrope) est un modèle simplifié d'hydrodynamique radiative (cf [24], [26]), dont certains régimes limites ont été proposés par Lowrie, Morel et Hittinger [23] et plus récemment par Buet et Després [2]. L'étude mathématique des modèles de fluides radiatifs n'en est qu'à ses débuts.…”

Section: Vii-1unclassified

Résultats d’existence globale et limites asymptotiques pour un modèle de fluide radiatif

Danchin¹,

Ducomet²

2015

Séminaire Laurent Schwartz — EDP Et Applications

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“…열복사의 주성분은 낮은 에너지 광자의 흐름으로서 매질의 운동이 빛의 속도보다 느리기 때문에 상 대론적 효과를 배제된 광자 수송방정식의 해석이 가능하다 [10]. 또한 유체 운동에 비해 분자 이온화과정은 매우 짧은 시간에 발생하므로, 열복사가 순간적으로 단위 체척 내 열평 형 LTE(Local Thermodynamic Equilibrium)이 성립되므로 화구 에 대한 지배방정식은 다음과 같이 표현된다 [5].…”

Section: 지배방정식unclassified