Title of article :
Design, Numerical Simulation and Experimental Investigation of Radial Inflow Micro Gas Turbine
Author/Authors :
Shah, S. P Mechanical Engineering Department - C. K. Pithawalla College of Engineering and Technology, Surat, India , Channiwala, S. A Mechanical Engineering Department - S V National Institute of Technology, Surat, India , Kulshreshtha, D. B Mechanical Engineering Department - C. K. Pithawalla College of Engineering and Technology, Surat, India , Chaudhari, G. C Mechanical Engineering Department - C. K. Pithawalla College of Engineering and Technology, Surat, India
Abstract :
The work arose initially from an interest in design of radial turbine for small scale gas turbine applications
typically suitable for distributed power generation system which demands compact installations. The paper
describes an investigation in to the design and performance of radial inflow turbines having a capacity of
25kW at 1,50,000 rpm. First a non-dimensional design philosophy is deduced to design a turbine rotor. The
design approach is largely one dimensional along with empirical correlations for estimating losses used to
obtain the main geometric parameters of turbine. From the proposed design approach, turbine total-to-static
efficiency is calculated as 84.91% which is reasonably good. After that a modified vortex design procedure is
developed to derive the non-dimensional volute geometry as a function of azimuth angle for actual flow
condition. Once a specific turbine is designed, the flow is analyzed in detail using a three-dimensional
Computational Fluid Dynamics (CFD) code in order to assess how accurately the performance is predicted by
simple meanline analysis. Finally, a fully instrumented experimental setup is developed. The experimental
investigations have been carried out to study the temperature and pressure distribution across turbine and
total-to-static efficiency is calculated. The limitations of surging and choking in compressor as well as in the
bearings to take up load at such high speed has allowed the tests to be conducted upto 70000 rpm only, with
turbine inlet temperatures ranging from 900 K to 1000 K and a pressure ratio upto 1.79, which developed
power in the range of 1.69 kW to 10.22 kW. The uncertainty bands are in order of ±13.76% to ±3.12%. It is
observed that the CFD results are in good agreement with test results at off design condition. CFD models
over predicted total to static efficiency by order of 7-8% at lower speed. These deviations are reduced as
turbine runs close to design point.
Keywords :
Alternate design , Radial turbine , Small gas turbine , Volute design , Turbine design
Journal title :
Astroparticle Physics
