Computational fluid dynamics analysis of a mixed flow pump impeller

Abstract

To improve the efficiency of mixed flow pump, Computational Fluid Dynamics (CFD) analysis is one of the advanced tools used in the pump industry. A detailed CFD analysis was done to predict the flow pattern inside the impeller which is an active pump component. From the results of CFD analysis, the velocity and pressure in the outlet of the impeller is predicted. CFD analyses are done using Star CCM+ software. These outlet flow conditions are used to calculate the efficiency of the impeller. The calculated value of efficiency from the empirical relations is 55%. The optimum inlet and outlet vane angles are calculated for the existing impeller by using the empirical relations. The CAD models of the mixed flow impeller with optimum inlet and outlet angles are modeled using CAD modelling software ProE WF3. To find the relationship between the vane angles and the impeller performance the optimum vane angle is achieved step by step. Three CAD models are modeled with the vane angles between existing and optimum values. These models are analyzed individually to find the performance of the impeller. In the first case, outlet angle is increased by 5°. From the outlet flow conditions, obtained from the CFD analysis, it is evident that the reduced outlet recirculation and flow separation cause the improved efficiency. By changing the outlet angle the efficiency of the impeller is improved to 59%. In the second case inlet angle is decreased by 10%. The efficiency of the impeller in this case is 61%. From this analysis it is understood that the changes in the inlet vane angle did not change the efficiency of the impeller as much as the changes in outlet angle. In the third case, impeller with optimum vane angles is analyzed and the outlet flow conditions are predicted. From the CFD analysis the efficiency of the impeller with optimum vane angles is calculated as 65%. Thus, efficiency of the mixed flow impeller is improved by 18.18% by changing the inlet and outlet vane angles.

Review on design improvement of mixed flow pump

“…The increased outlet angle leads to smooth flow in exit region. [7] Figure 7. Head developed by the existing and modified impeller [7] The characteristic curve between discharge and overall efficiency is given in Fig .12.…”

“…[7] Figure 7. Head developed by the existing and modified impeller [7] The characteristic curve between discharge and overall efficiency is given in Fig .12. It shows that overall efficiency for the existing impeller starts decreasing after 11 lps.…”

“…Due to high discharge rate, velocity of the flu id increases and this high velocity cause cavitations losses and recirculation inside the impeller. [7] Figure 8. Efficiency of the existing and modified impeller [7] Mr. Jidong Lia has claimed that under filling impeller blades at the trailing edge improved the performance of the pump.…”

Design and CFD Analysis of Liquid Ring Vacuum Pump

“…A vacuum pump is a device for creating, improving and/or maintaining a vacuum [1,2]Mechanical vacuum pumps works by the process of positive gas displacement, that is, during operation the pump periodically creates increasing and decreasing volumes to remove gases from the system, and exhaust them to the atmosphere [5]. Two basically distinct categories may be considered gas transfer pumps and entrapment or capture pumps [4].…”

Evaluation of Synergism in Sodium Tungstate/Sodium Silicate - (PA-Zn2+) System for Mitigating Mild Steel Corrosion in Industrial Cooling Water System

“…as corrosion inhibitors in aqueous as well as acidic medium [4][5][6][7][8]. Studies also reported that the addition of Zn 2+ to the inhibitors brought a positive effect in the inhibition efficiency [9]. Literature supported the use of phthalic acid as a corrosion inhibitor in acidic as well as aqueous environment [10].…”