Abstract The main function of the breeder materials, such as Li2TiO3, Li4SiO4, and Li2ZrO3, in a solid type breeding blanket is to produce tritium, which is transferred to the fuel cycle system by helium purge gas and is used as a fuel for nuclear fusion reactions. Since the configuration of the breeder should be designed considering the purge gas flow, the form of pebble beds is mainly adopted, thereby leading to the smooth flow inside a blanket. The flow characteristics can be important design drivers because they also affect the design of the fuel cycle system. In order to increase a tritium production rate, a large number of breeders should be placed in the same space and various sizes of pebbles instead of one size of pebbles can be thus applied to increase the packing fraction of pebble beds. In this case, however, the flow resistance may increase and hence the relationship between the pebble bed configuration and the purge gas flow should be carefully investigated. In this study, a computational framework for one-way coupling analysis of the discrete element method and computational fluid dynamics is established to simulate the purge gas flow through binary-sized pebble beds. The configurations of pebble beds are obtained using the discrete element method and their geometries are modified by smoothing the sharp circular edges at the contact points of pebbles to construct proper meshes for computational fluid dynamics simulations. The flow resistance of binary-sized pebble beds is then investigated in terms of the pressure drop in the breeding zone.

中文翻译：

---

使用离散元方法和计算流体动力学对通过二元尺寸球床的吹扫气流进行数值研究

摘要 增殖材料 Li2TiO3、Li4SiO4 和 Li2ZrO3 在固体增殖毯中的主要作用是生产氚，氚通过氦吹扫气转移到燃料循环系统，用作核聚变燃料。反应。由于增殖器的配置应考虑吹扫气流，因此主要采用球床形式，从而使毯内流动顺畅。流量特性可能是重要的设计驱动因素，因为它们也会影响燃料循环系统的设计。为了提高氚产率，应在同一空间内放置大量的饲养者，可以用不同尺寸的鹅卵石代替一种尺寸的鹅卵石，以增加卵石床的填充率。然而，在这种情况下，流动阻力可能会增加，因此应仔细研究球床配置和吹扫气流之间的关系。在这项研究中，建立了离散元方法和计算流体动力学的单向耦合分析的计算框架，以模拟通过二元尺寸球床的吹扫气流。使用离散元方法获得卵石床的配置，并通过平滑卵石接触点处的尖锐圆形边缘来修改其几何形状，以构建适合计算流体动力学模拟的网格。然后根据繁殖区的压降研究二元大小的卵石床的流动阻力。