Deriving Explicit Equations for Optimum Design of a Circular Channel Incorporating a Variable Roughness

作者：Niazkar Majid; Rakhshandehroo Gholam Reza^*; Afzali Seied Hosein

来源：Iranian Journal of Science and Technology-Transactions of Civil Engineering, 2018, 42(2): 133-142.

DOI：10.1007/s40996-017-0091-y

• Circular channel
• Optimum design
• Variable roughness
• Manning's equation
• Explicit design equations
• Hybrid method

The need for optimum design of water conveyance structures provides an active area of study in water resources engineering. A literature review on optimum design of circular channels indicates that variation of Manning's roughness coefficient (n) with water depth is not taken into account. In this study, this variation has been implemented in the optimum design of lined circular channels. The significant discrepancy between the results obtained for constant and variable roughness scenarios demonstrates the necessity for considering roughness coefficient variability with water depth in circular sections. Furthermore, a new explicit equation for optimum design of section parameters has been proposed using a hybrid optimization technique, which combines the Modified Honey Bee Mating Optimization with Generalized Reduced Gradient algorithms. Solving a typical design problem in the literature by the proposed equation showed not only its adequate performance but also the necessity for considering variable roughness in circular channels design procedure.

• 出版日期2018-6