Design and Analysis of Centrifugal Pump

Abstract

Centrifugal pumps are used in various applications and are integral to many industries. Yet, in spite of their prevalence and relatively simple configurations compared to other turbo machines, designing an efficient and durable pump remains a challenge. The design of centrifugal pump is based on empirical relation. In last 10 years the design and performance of centrifugal pump has great progress due to evolution of accuracy of numerical methods and computer power. In this dissertation the radial flow centrifugal pump has been studied which is use for cooling of 55hp wankel engine of speed 7000rpm. Centrifugal pump supplies the cooling water to the engine with flow rate 65lpm with water circuit temperature below 75oC. The design of centrifugal pump impeller has been calculated for 65hp engine with 12m head. To maintain the temperature below 75oC, the flow rate required for new centrifugal pump is 80 lpm. Due to geometrical constraint of engine assembly, only impeller of centrifugal pump is modified, which involve number of dependent variables. The impeller vane angle and number of vane are the most critical parameters in impeller design. Here two different design cases for impeller has been proposed. A code has been developed to simplify iterative process for design using MATLab. Design automation has been successfully implemented between Excel Spread sheet and solid modelling software, which reduce the time and cost of 3D modelling and 2D drafting. CFD analysis has been performed to achieve required discharge and head for both design cases. The pressure distribution have been obtained after CFD analysis is further used for static structural FE analysis. The total deformation and von Mises stress profile has been determined using FE analysis to check rigidity and strength of impeller. Case 2 design is better compare to case 1 because of high head and discharge as well as low deformation and von Mises stress.