Affiliation:
1. 1 Department of Water Conservancy Engineering, Zhengzhou University, No. 100, Kexuedadao Road, Zhengzhou 450001, China
Abstract
Abstract
The deposition of sediments with different roughness increases uncertainty in the prediction of effective Manning's n (also known as composite roughness). In this paper, the changing rules of composite roughness and the influence on the discharge capacity of drainage pipes under different flows and slopes were studied by experimental measurement and numerical simulation. When the Froude number is less than 1, the composite roughness decreases gradually with the increase of flow. When the Froude number is more than 1, the composite roughness increases at first and then decreases with the increase of flow. It also showed that the different bed roughness has a great influence on composite roughness, which affects the hydraulic characteristics of flow. The composite roughness of the drainage pipe increases as the bed roughness increases. The water surface rises and the average velocity decreases under a certain slope and flow. The formulas for calculating the composite roughness are obtained by analogy analysis, which can provide theoretical support for the design of the drainage pipeline.
Funder
National Key Research and Development Program of China
National Natural Science Foundation of China
Program for Innovative Research Team (in Science and Technology) in University of Henan Province
Key Scientific Research Projects of Colleges and Universities in Henan Province
Open Research Fund of Key Laboratory of Water-saving Irrigation Engineering of the Ministry of Agriculture and Rural Affair
Open Research Fund of MWR Key Laboratory of Lower Yellow River Channel and Estuarine Regulation
Fundamental Research and Cultivation of Young Teachers of Zhengzhou University in 2022
First-class special fund of Yellow River Laboratory
Subject
Water Science and Technology