INTERNATIONAL JOURNAL FOR TRENDS IN ENGINEERING & TECHNOLOGY VOLUME 5 ISSUE 2 – MAY 2015 - ISSN: 2349 - 9303
Design and Analysis of Turbine Blades in a Micro Gas Turbine Engine Lakshmy Devi.S.M Aeronautical Engineering Department, PMC Tech, Tamil Nadu lakshmysm@gmail.com Abstract— This paper is based on the design and analysis of turbine blades in a micro gas turbine engine. Micro-gas turbine engines offer advantages over the other technologies for small-scale power generation. A combustor is the heart of any engine; where in the micro gas turbine, it should be compact, simple, inexpensive and robust in construction. The burned gases from the combustor pass through the turbine blades. The designing and manufacturing of the turbine blades are very difficult when the blade angle, blade size and shape are considered. The design of the turbine blade passages is broadly based on aerodynamic considerations and it is to obtain optimum efficiency, compatibility with compressor and combustor design. For this, the specifications of many micro gas turbine engines are taken by conducting a literature survey to get the design data for an apt turbine blade. By these values, the flow parameters of the engine are obtained and are taken for analyzing purposes to get increased momentum thrust. Here, the design is done by using the software CATIA and it is then exported to FLUENT for analyzing. The result shows that the estimated design and performance is achieved. Index Terms — Blade angle, CATIA, FLUENT, Micro Gas Turbine engine, Turbine blades. —————————— ——————————
1 INTRODUCTION An engine or motor is a machine designed to convert energy into useful mechanical motion. A gas turbine is a rotary engine that extracts energy from a flow of combustion gas. It has an upstream compressor coupled to a downstream turbine, and a combustion chamber in-between. Energy is added to the gas stream in the combustor, where fuel is mixed with air and ignited. In the high pressure environment of the combustor, combustion of the fuel increases the temperature. The products of the combustion are forced into the turbine section. There, the high velocity and volume of the gas flow is directed through a nozzle over the turbine blades, spinning the turbine, which powers the compressor and drives the mechanical output for some turbines. The energy given up to the turbine comes from the reduction in the temperature and pressure of the exhaust gas.
Micro turbines are becoming widespread for distributed power and combined heat and power applications. They are one of the most promising technologies for powering hybrid electric vehicles. They range from hand held units producing less than a kilowatt, to commercial sized systems that produce tens or hundreds of kilowatts. Basic principles of micro turbine are based on micro combustion.
2 THEORETICAL CALCULATION FOR ENGINE DESIGN By using isentropic relations and Area-Mach number relation, calculations of the engine parameters are done. Table 1: ENGINE PARAMETERS
Fig 1: MGT
170
Mach
Pressure (bar)
0.56 0.51 0.185 0.277 0.409 0.709
1.01325 1.253 4 3.91 1.024 0.917
Temper ature (K) 288.16 306.31 427.06 873 626.09 609.27
Density (kg/m3) 1.225 1.052 3.26 1.56 0.569 0.524
Area ×10 -3 (m2) 1.328 1.646 1.24 1.24 2.72 1.73
Velocity (m/s) 190.55 179.01 76.68 160.24 200.27 341.91