Executive Summary

This project is collaboration between the Department of Mechanical and Materials UKM and the Department of Water of Irrigation. The latter observed high maintenance costs due to damages to pumps as results of damages by instability of water entering the pump. Anti-vortex device (AVD) is a device designed to suppress vortices that exist in pump sump. The existence of vortex is not desired because it causes the flow to approach the pump impeller blade at an angle which can lead to vibration to the pump and cavitation inception on the surface of impeller blade. Vortices that occur in a pump sump could take place either on the surface, which is called surface vortex, or at the wall boundaries of the sump, namely submerged vortex. In this project experimental approaches including the use of measuring equipment such as swirl meter and photographic devices such as high speed cameras are used to capture flow structures produced by the newly designed plate type floor splitter which could suppress submerged vortices originated from the geometries of a sump. Prior to undertaking the experimental works, the design of plate type floor splitter of a transfer pump equivalent to an industrial use are properly prepared. Both stress and strain analysis as well as fluid dynamics analysis will have to be completed using existing commercial-type modelling software. A properly designed sump and impeller with this vortex suppresser avoids damage to the pump therefore minimize maintenance fees and at the same time avoid potentially catastrophic damages to connected water infrastructure= and the system it supports due to damaged pumps. This project benefits the designing and the maintenance department catering for large amount of water transfer projects such as

the storm water management group, large-scale water supply for agriculture or water transfer projects.

Description

The aim of the study is to determine the optimal design of plate used as floor splitter to effectively reduce submerged vortices in pump intake by experimental and numerical approach. Therefore, the research methods that will be used to accomplish the goal of this study are summarized as follows: Numerical modelling and calculation The pre-determined test subjects will be constructed virtually by means of numerical modelling and the predicted flow pattern will be established with the aid of CFD software. The constructed test models will follow the dimensions and environment of the actual experimental setup to ensure accuracy of the predicted results. Experimental measurement After obtaining results from the CFD simulation, the data will be studied and shapes that are possible to be manufactured as prototypes will be selected and prepared for the experimental stage of the study. At the same time, the experimental setup consists of pump intake sump, axial flow pump, flow circulation pipe and flow regulator will be prepared. The use of PIV will be incorporated to capture the actual velocity profile of the selected shape

along with the vorticity at the pump intake. Data analysis Images that are captured with the PIV equipment will be processed using special software into analyzable figures. The two dimensional flow field acquired from the measurement will be integrated to create a three dimensional field. Scope of study and theoretical framework The scope of the study focuses on splitter type AVD in the form of a plate. The modification of the plate is not restricted to the geometric shape only but also to other design variables such as the orientation and profile of the plate. The type of vortex to be evaluated is submerged vortex, which can arise from floor, back wall and side wall of the pump sump. The velocity profiles which determine the vorticity of the flow, are to be captured in the area of pump intake directly below the pump suction bell. Independent and dependent variables are outlined at the preliminary stage of the study to build up a theoretical framework which plays an important role in guiding the entire process of the research study.

Progress

Drawings of the newly built channel flow
Building the channel flow	Channel flow ready for pump and pipe
The submegred vortex appear during pump operation	PIV
PIV images	Contours

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