Volume 3 | Issue 2 ©2017 IJIRCT | ISSN: 2454-5988 IJIRCT1701001 International Journal of Innovative Research and Creative Technology www.ijirct.org 1 Performance & Cavitation Characterization of Mixed Flow Centrifugal Pump using CFD Simulation Gaurav Chakraborty P.G. Scholar, Department of Mechanical Engineering C.C.E.T Bhilai, India R.K. Rathore Asst. Prof., Department of Mechanical Engineering C.C.E.T Bhilai, India Abstract—Centrifugal Pumps are the most common appliances used in various industries, agriculture and domestic application& thus its impeller design thus required a very precise understanding of the internal flow at rated and part load operating conditions. For the cost effective design of pump, it is thus very essential to predict its performance in advance before manufacturing them, which requires understanding of flow behavior in different parts of pump & problems arises due to cavitation. In the present work, firstly performance analysis of centrifugal impeller pump is being carried out by performing analysis on its pressure distribution, velocity distribution from which power and efficiency is being calculated and validated. On the later part, analysis is carried out to perform cavitation2 analysis at various mass flow rate at different rated speed of the pump. Also, the threshold value of mass flow rate is being identified from where a cavitation phenomenon is observed at respective rated speed in order to reduce it. Keywords— Centrifugal Pump [1], Cavitation [2] I. INTRODUCTION Pump is a mechanical device mostly used for raising liquids from a lower level to a higher one. This is done by creating a low pressure at the inlet and high pressure at the outlet of the pump. However, initially work has to be done by a prime mover to enable it to impart mechanical energy to the liquid which ultimately converts into pressure energy. It is mostly in used in industries and residential applications. A centrifugal pump is a non-positive displacement pump that imparts energy to a liquid. Centrifugal pumps are the machines, which utilizes centrifugal force in order to lift fluid from a lower level to a higher level by developing pressure. The centrifugal pump moves liquid by rotating one or more impellers inside a volute casing. The liquid is introduced through the casing inlet from the eye of the impeller where it is picked up by the impeller vanes. In other words, the fluid turbo machinery essentially consists of an impeller rotating in a casing. Fluid enters from the eye of the impeller (at the center of the impellers) and exits though the space between the impeller blades to the space between the impeller and casing walls. The velocity of fluid elements is in both tangential and radial directions, as the impeller start rotating. The velocity as well as the pressure, both increases, relatively, as the fluid flows from the impeller. A. Working Principle A centrifugal pump consists of a set of rotating vanes enclosed within a housing or casing that is utilized to impart energy to a fluid through centrifugal force. The vanes are usually slope backwards, away from the direction of rotation. The blades of the rotating impeller transfer energy to the fluid & thus increase velocity. The fluid is sucked into the impeller through impeller eye and flows through the impeller channels formed by the curved blades between the shroud and hub. The fluid is accelerated by pulse transmission while following through the curvature of the impeller vanes from the impeller Centre (eye) outwards. It reaches its maximum velocity at impeller’s outer diameter and leaves the impeller into a diffuser or volute chamber. II. LITERATURE REVIEW Centrifugal pumps are mostly used in many industrial, agricultural and household applications, so the pump system may be required to operate over a wide flow range in different applications. The most previous numerical studies were focused on the design or near-design state of pumps. Few efforts were made to study the off-design performance of pumps, where the performance of pump deteriorates [4]. With the aid of the CFD approach, the complex internal flows through the different components of pump can be studied at different operating conditions which help in improvement in the performance at off design conditions. Mentzoset al. [1] carried out a numerical simulation of the internal flow in a backward curve vanned centrifugal pump. The MRF approach used to take into account the impeller- volute interaction was completely failed, due to its fixed coupling formulation. However, it is recommended for basic understanding of the flow at various operating points. The transient analysis was suggested as a real tool for understanding of the interaction between impeller and spiral casing. Bacharoudis et al. [2] in 2008 in his research stated various parameters affect the pump performance and energy consumption. In this study, the performance of impellers with the same outlet diameter having different outlet blade angles is thoroughly evaluated. For each impeller, the flow pattern and the pressure distribution in the blade passages are calculated and finally the head-capacity curves are compared with the theoretical one. When the pump operates at off-design conditions, the percentage raise of the head curve, due to the increment of the outlet blade angle, is larger for high flow rates and becomes smaller for flow rates Q/QN<0.65. When pump operates at nominal capacity, the gain in the head is more than