Two-Dimensional Numerical Analysis of Multi-Caliber Drainage Pipe Impact Mechanism with Barrier on the Transition Process of Convective System

The water carrying capacity and head loss of pipelines are significantly affected by the flow state, aiming at the problem that the transition flow characteristics of multi caliber basalt fiber drainage pipe are not clear, based on the two-dimensional numerical simulation results of multi-diameter pipes with barriers, this paper systematically analyzes the transition path and transition mechanism of the multi-diameter drainage pipe convection system under the action of barriers in the range of Re = 103 − 2.73 × 108. The results show that: 1) The main mode solution of multi-aperture basalt fiber drainage pipe convection system is steady flow in the process of transition to chaos. 2) Compared with the non-barrier condition, the transition process of the multi-aperture basalt fiber drainage pipe with the barrier is obviously delayed, that is, the critical Reynolds number of the convective system evolving from laminar flow to turbulent flow is larger. The research results show that the design of the barrier can effectively improve the water conveyance capacity of the pipeline, which can provide reference for the optimal design of multi-diameter drainage pipes.