论文标题
辐射转移问题的渐近$ p_n $近似
Asymptotic $P_N$ Approximation in Radiative Transfer Problems
论文作者
论文摘要
我们研究了光子辐射传递中时间依赖性渐近$ p_n $近似的有效性。时间依赖性渐近$ p_n $是一个近似值，它使用标准$ p_n $方程进行封闭，该方程基于确切的Boltzmann方程的渐近解决方案，以解决均质问题，在时空和时间上。用于辐射转移的渐近$ p_n $近似需要仔细的闭合方程处理。具体而言，由于内部或外部辐射源，必须扩展每个碰撞发射的粒子的平均粒子（$ω_ {\ mathrm {eff}} $）可能大于一个粒子，并且必须扩展闭合系数。我们的近似值针对众所周知的辐射转移基准测试。它产生了出色的结果，几乎正确的粒子速度可以控制辐射热浪前部。
We study the validity of the time-dependent asymptotic $P_N$ approximation in radiative transfer of photons. The time-dependent asymptotic $P_N$ is an approximation which uses the standard $P_N$ equations with a closure that is based on the asymptotic solution of the exact Boltzmann equation for a homogeneous problem, in space and time. The asymptotic $P_N$ approximation for radiative transfer requires careful treatment regarding the closure equation. Specifically, the mean number of particles that are emitted per collision ($ω_{\mathrm{eff}}$) can be larger than one due to inner or outer radiation sources and the coefficients of the closure must be extended for these cases. Our approximation is tested against a well-known radiative transfer benchmark. It yields excellent results, with almost correct particle velocity that controls the radiative heat-wave fronts.
