MODELLING FLUID FLOW IN AN OPEN CIRCULAR CHANNEL WITH THREE LATERAL INFLOWS

Abstract

Kenya has been experiencing heavy rains in recent years, leading to significant flooding challenges. A flood happens when water spills over and covers land that is usually dry. Flooding can happen gradually over a long period or very quickly, within minutes. Floods are the most common natural disaster globally, causing extensive damage to properties and infrastructure. Therefore, there is a need to construct channels that divert water into rivers, lakes, and the ocean to reduce flooding. Many researchers are working to design drainage systems, navigation channels, irrigation canals, and ditches to efficiently convey water and generate hydroelectric power. Circular - shaped channels with three inflows have received less attention in open channel flow studies than rectangular, parabolic, trapezoidal, and horseshoe - shaped channels. This study aimed to model fluid movement in an open circular conduit that contains an incompressible Newtonian fluid and has three lateral inflows. Also, the research investigated consequences of raising length of the lateral entry channels, the lateral inflow’s angle channels (ranging from 0 0 to 900) on the cross - sectional area and the primary open channel’s velocity.Flow was controlled by the continuity and momentum equations. Via the application of a similarity transformation, these equations were changed to a set of ordinary differential equations that are non - linear. Following that, the finite difference approach was used to solve the resultant system numerically. Python software was used to analyse the results obtained from this study for the hydraulically efficient open circular channels, The results were subsequently presented in graphical form. The equations were first represented in dimensionless form. The findings showed that when lateral inflow increased, the main channel’s velocity decreased. Furthermore, it was noted that the velocity decreased as the lateral inflows’ angles increased. Similarly, the principal channel’s velocity decreased as the cross - sectional area of the lateral inflows increased. It is hoped that the findings of this study would be helpful to engineers when designing open circular channels with three lateral inflows that maximize hydraulic efficiency and water transfer capacity. These channels could be utilized for various applications, including flood mitigation, hydroelectric power generation, irrigation, and high - speed water operations in water mills