submain meaning in Chinese

次斡管
次主管
地下总管
分干管
分干线
辅助干线；次干管
干线的分支
支水管

Optimal design for the best submain position of micro - irrigation on slope with paired laterals by genetic algorithms
微灌坡地双向毛管最佳支管位置遗传算法优化设计
It is to divide the domain over which the problem is defined into subdomains , and solve th submain problem in parallel
该方法先将偏微分方程求解区域划分为若干个子区域，然后在各个子区域并行求解。