论文标题
非线性Fokker-Planck加速器,用于板几何形状中的前向运输问题
Nonlinear Fokker-Planck Acceleration for Forward-Peaked Transport Problems in Slab Geometry
论文作者
论文摘要
本文介绍了一种非线性加速技术,该技术可以加快运输问题解决方案的收敛性,并具有高度前向的散射。该技术类似于常规的高阶/低阶(HOLO)加速度方案。 Fokker-Planck方程是在高度向前的设置中的传输方程的渐近极限,已修改并用于加速。这个修改的方程可保留(高阶)传输方程的角磁通和矩。我们使用筛选的Rutherford,指数和Henyey-Greenstein散射内核提出数值结果,并将它们与建立的加速方法(例如扩散合成加速度(DSA))进行比较。与DSA相比,我们观察到壁挂时间的三到四个数量级的速度。
This paper introduces a nonlinear acceleration technique that accelerates the convergence of solution of transport problems with highly forward-peaked scattering. The technique is similar to a conventional high-order/low-order (HOLO) acceleration scheme. The Fokker-Planck equation, which is an asymptotic limit of the transport equation in highly forward-peaked settings, is modified and used for acceleration; this modified equation preserves the angular flux and moments of the (high order) transport equation. We present numerical results using the Screened Rutherford, Exponential, and Henyey-Greenstein scattering kernels and compare them to established acceleration methods such as diffusion synthetic acceleration (DSA). We observe three to four orders of magnitude speed-up in wall-clock time compared to DSA.