AI 中文总结
针对纳米尺度热输运中声子输运偏离经典傅里叶描述的问题，提出NanoBTE求解器，采用有限体积法，支持多种条件，有迭代方案及任务分解策略，可加速收敛并实现并行化与GPU加速。
AI 中文摘要
纳米尺度的热耗散已成为先进半导体器件中的关键挑战，其中由于边界散射和弹道效应，声子输运可能会严重偏离经典傅里叶描述。在这里，我们提出了NanoBTE，这是一种在弛豫时间近似下用于非灰色声子玻尔兹曼输运方程的确定性有限体积求解器。NanoBTE支持复杂的二维和三维几何形状、带分辨的声子特性、离散坐标角积分、体积热生成以及多个声子边界条件，包括热化、漫反射和镜面反射。为了提高多尺度模拟的效率，我们实现了顺序迭代和合成迭代方案，后者将微观声子输运方程与宏观扩散型温度方程耦合，以加速近扩散区域的收敛。此外，NanoBTE采用带方向任务分解策略，实现基于MPI的高效CPU并行化和主导稀疏输运操作的GPU加速。
英文摘要
Nanoscale heat dissipation has become a critical challenge in advanced semiconductor devices, where phonon transport can strongly deviate from the classical Fourier description due to the boundary scattering and ballistic effects. In this work, we propose NanoBTE, a deterministic finite-volume solver for the non-gray phonon Boltzmann transport equation under the relaxation-time approximation. The solver supports complex two- and three-dimensional geometries, band-resolved phonon properties, discrete-ordinates angular quadrature, volumetric heat generation, and multiple phonon boundary conditions, including thermalizing, diffuse, and specular reflections. %To improve the efficiency of multiscale simulations, both sequential and synthetic iterative schemes are implemented, where the latter couples the microscopic phonon transport equation with a macroscopic diffusion-type temperature equation to accelerate convergence in near-diffusive regimes. Both sequential and synthetic iterative options are implemented for the steady-state solution. Furthermore, NanoBTE adopts a band-direction task decomposition strategy, enabling efficient MPI-based CPU parallelization and GPU acceleration of the dominant sparse transport operations.
Comments29 pages, 9 figures
