In general, the accrual is too obvious to be ignored in engineering design, especially when the flow quantity is large and there are many elbows (for example, in regional drainage).

• 污水两相流动时的局部阻力显著地大于清水流动时，在工程设计中不可忽视，尤其是在流量大、弯管多的情况下（如区域排水系统中）。