Title: Aerodynamic design and computational fluid dynamic analysis of radial outflow turbines for steam Rankine cycle and supercritical carbon dioxide Brayton cycle

Authors: Vijayaraj Kunniyoor; Punit Singh; Karthik Nadella

Addresses: Department of Mechanical Engineering, Indian Institute of Science Bangalore, Bangalore-560012, India ' Centre for Sustainable Technologies (CST), Interdisciplinary Centre for Energy Research (ICER), Indian Institute of Science Bangalore, Bangalore-560012, India ' Interdisciplinary Centre for Energy Research (ICER), Indian Institute of Science Bangalore, Bangalore-560012, India

Abstract: The first part of this paper presents the design of a radial outflow steam turbine for a micro steam power pump block of 200 kW capacity based on a unique Ljungstrom turbine design methodology. Computational fluid dynamic (CFD) simulations were carried out for the 18-stage radial outflow steam turbine at design and off-design points, and results proved the validity of the undertaken design methodology. The design point CFD simulation showed a total to total efficiency of 74.4% for the steam turbine. Specific speed and specific diameter values for the radial outflow steam turbine stages were calculated and superimposed on the Balje's specific speed-specific diameter chart, thus identifying a unique radial outflow turbine zone in the chart. The second part of this paper presents a new design methodology based on specific speed and specific diameter values for designing a supercritical carbon dioxide radial outflow turbine for a 1 MW supercritical carbon dioxide (SCO₂) Brayton cycle. CFD simulations were carried out at design and off-design points for the SCO₂ turbine. The total to total efficiency from the CFD simulation at the design point for the SCO₂ turbine is 84.6%.

Keywords: radial outflow turbine; ROT; steam; supercritical carbon dioxide; specific speed-specific diameter chart.

DOI: 10.1504/PCFD.2021.113674

Progress in Computational Fluid Dynamics, An International Journal, 2021 Vol.21 No.2, pp.65 - 90

Received: 21 Feb 2020
Accepted: 13 May 2020
Published online: 16 Mar 2021 *

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