DESIGN OF SINGLE STAGE AXIAL POWER TURBINE ON ULTRA MICRO GAS TURBINE ENGINE

• Main Author: Gidion Solissa, Rizal
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/79425
• Institution: Institut Teknologi Bandung

The increasing demand for electrical energy today, it requires several alternative power and electrical energy storage. With the development of current battery technology, especially Li-ion batteries, it still has shortcomings in terms of energy density so there is an incentive to develop a system that can use the energy stored in fuel, but has a small size, so that it can be used in devices that generally use batteries. One system that can be developed to meet these needs is the ultra-micro gas turbine. Ultra-micro gas turbines are energy conversion systems based on the Brayton cycle. The simplest gas turbine consists of three main components, namely the compressor, combustion chamber, and turbine. The design of the single-stage axial power turbine of the ultra-micro gas turbine is carried out starting from the parametric cycle design. After obtaining the performance map at several points, the design point can be determined as the point that has the best potential thermodynamically. With the thermodynamic design point, the design of the single-stage axial power turbine can be carried out, taking into account the input from the design point as well as from other components, especially the compressor, and combustion chamber. The single-stage axial power turbine is designed to drive a BLDC electric motor generator that will produce 600 watts of power, based on the parametric cycle of the GT 2025 turbocharger and combustion chamber. To drive the single-stage axial power turbine, it is utilized based on the exhaust gas from the turbine on the GT2052 turbocharger which has an efficiency value of 70%. The designed single-stage axial power turbine is expected to have an efficiency value of 90% and can supply power to the BLDC electric motor generator of 600 watts, the single-stage axial power turbine was chosen as the design design, with the aspect ratio ratio in the stator and rotor blades of the same value, the aim is to facilitate the manufacturing process. The design of this single-stage axial turbine is based on the design points that have been agreed upon with the UMGT research team, namely the mass flow (?) of 0.08574 kg/s, with a total pressure at the inlet of 110983.7531 Pa, total pressure at the outlet of 106024.9654 Pa, total inlet temperature of 791.923 K, with a rotary rotation of 12400 rpm. The results of the calculation analysis obtained the number of blades on the stator which is 32 and the number of rotor blades 33, annulus height 0.01 m and diameter 0.14 m. The method used in predicting the performance value of this single-stage axial turbine is the free fortex analysis method with a 50% weighting stage of the reaction stage, and the reaction variation (R) of the axial turbine (R.I Lewis, 1996). The design of turbine blades for stator and rotor using Cascade software, the airfoil used is NACA 0012, the camber line on the two-dimensional airfoil uses a circular arc type with a profile thickness scale of 1.5 and the profile shape of the stator and rotor blades is twisted. After obtaining the profile of the stator and rotor blades, then analyzed using Computational Fluid Dynamics (CFD) Ansys CFX 2019, to design and optimize power turbine turbomachinery, the use of Ansys CFX because it has accuracy for turbomachinery with extensive industry validation, the efficiency obtained in this simulation is more than 95% greater than the analytical method of R.I. Lewis. The power generated is 613.93 watt. with air mass flow of 0,086 kg/s, a pressure ratio of 1.033 bar and a temperature drop of 6.63 K. This single-stage axial power turbine on an ultra-micro gas turbine can be utilized as a battery replacement in UAVs, which is a portable energy source including being a power source for UAVs (Unmaned Aerial Vehicles). The gas turbine has a high power to weight ratio making it very suitable for a hybrid system with UAV electric motors.