International Journal of Advanced Engineering Research and Science (IJAERS) [Vol-3, Issue-10, Oct- 2016] https://dx.doi.org/10.22161/ijaers/3.10.22 ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 138 Experimental Evaluation of Electrolyte Flow Pattern in ECM Tool Using CFD Analysis Gali Chiranjeevi Naidu, K Dharma Reddy, P V Ramaiah Department of mechanical engineering, SV University College of engineering, Tirupati, Andhra Pradesh, India Abstract — In this present study, three dimensional flow pattern of Electrochemical Machining process has been simulated using Computational Fluid Dynamics (CFD) in L-shaped tool model. The ANSYS software is used for the design and analysis of a model. Different process parameters like volume fraction profile, velocity profile, pressure profile temperature profile and heat flux profile of electrolyte flow in the Inter Electrode Gap (IEG) etc. have been evaluated from the simulation using this model. The results indicated generation of hydrogen bubbles in which the turn reduced the volume fraction of brine depending upon the tool geometry. Reduced brine volume fraction led to reduction in MRR. As a result of hydrogen bubble formation, temperature towards the boundaries were increased rapidly as gaseous hydrogen bubbles possess sufficiently lower convective heat transfer coefficient as compared to liquid brine. For validating the simulation results, a set of experiments have been carried out on ECM by fabricating the tool geometry. The experimental results were analyzed by using MINITAB software. Keywords — CFD, ECM, Electrolyte, Flow pattern. I. INTRODUCTION Electrochemical machining (ECM) is one of the most potential un-conventional machining processes. The basic principle may be considered as the reverse of electroplating with some modifications. Further, it is based on the principle of electrolysis. In a metal, electricity is conducted by the free electrons, but it has been established that in an electrolyte the conduction of electricity is achieved through the movement of ions. Thus, the flow of current through an electrolyte is always accompanied by the movement of matter. Thus ECM can be thought of a controlled anodic dissolution at atomic level of the electrically conductive work-piece by a desired shaped tool due to flow of high current at relatively low potential difference through an electrolyte which is quite often water based neutral salt solution. ECM is one of advanced machining technologies and has been applied in highly specialized fields, such as aerospace, aeronautics, defense and medical industries. In present days, ECM is used in other industries such as automobile and turbo-machinery because of its various advantages. In case of complicated shapes of work-piece it is very difficult to know the machining variables distribution within the inter electrode gap (IEG). By studying the flow pattern of electrolyte, we can predict the machining variable distribution accurately and thus can avoid the passivation which is the major problem in ECM in complicated shape cases. Again, two phase effect (hydrogen bubble generation) has a major role on the machining variables as well as on the material removal rate and surface roughness. The flowing electrolyte collects the evolving hydrogen gas generated at the cathode. Electrolyte has three main functions in ECM. It carries the current between the tool and work piece, it removes the products of the reaction from the cutting region, and it removes heat produced in operation. Normal electrolyte used for ECM for all common metals & alloys is solution of Sodium Chloride (NaCl) in water. They react with the work piece and form a salt which dissolves in electrolyte. II. EXPERIMENTATION This deals with the experiment that has been conducted in the ECM set up. The experiments were conducted with L- shaped tool as per the dimensions of model to find out the MRR to validate the simulation results. 2.1. ECM Set up The ECM set up used for the experiment is as shown in the fig.2.1 and the control panel is as shown in fig.2.2. Fig.2.1: ECM set up used for the experiment