Cost Effective Method for Manufacturing Micro Gas Turbine Components

A 10 kW Micro Gas Turbine (MGT) is under development at the Propulsion Division, National Aerospace Laboratories, Bangalore for stationary power applications. The cost of the MGT unit depends on the manufacturing cost of the individual components and the number of units produced. There is a need to optimize the manufacturing processes to reduce the cost of production. The method of manufacturing the components through Rapid Prototyping (RPT) followed by investment casting was found to be cost effective and brought down the total cost of the unit considerably. This paper describes, in detail the manufacturing processes adopted for producing one of the MGT components, namely the compressor stage consisting of impeller and diffuser. A comparison of the dimensional accuracies, surface finish and typical cost involved in manufacturing the compressor component by conventional CNC milling machine and by casting through the RPT route is presented in this paper.