Simulation and analysis of investment casting process on Francis turbine runner

Abstract

The investment and sand casting have always been a problematic case for complex shapes such as turbines, blades, and so on in Nepal, and due to which this has always been ineffective regarding functionality and financial aspects, because of multiple iterations of casting. The casting of turbines in a single iteration with few defects would be beneficial both in terms of cost and material use as well as the environment. Necessary expertise in this field can be gained from casting simulation. The paper is about the use of casting simulators like ProCAST with CAD software to understand the better method for investment casting. The single gating system was approached with Caine’s method and Chvorinov’s method in casting. Also, a section of the runner was cast at Metal Cast Pvt. Ltd, Butwal, using sand casting which was verified on ProCAST. Investment casting of 92kW and 14 kW Francis’s runner turbine was simulated with minimum defects like shrinkage and porosity (under 4%) and CSF above 50%. Also, the Mass flowrate was around 2.23 kg/sec. Thus, the study deals with a better way to improve the investment casting of turbines through the help of simulation.