Aerothermal Design and Metamodel-Assisted Optimization of High-Speed Drive Turbine

Abstract

Abstract. This work explores the development of a high-speed drive system for scaled-down electrified shockwave turboreactors tailored to the laboratory requirements of a small-scale demonstrator. With shockwave turboreactors operating at extremely high rotational speeds and elevated temperatures, a direct electric motor drive is not feasible due to thermal limitations. A drive turbine is therefore proposed so that power can be provided to the shockwave turboreactor, adapted to the limitations that are particular to small-scale operation. A traditional design approach consisting of a preliminary 0D, 1D, and detailed 3D Computational Fluid Dynamics (CFD) analysis was conducted, incorporating design adjustments imposed by additive manufacturing constraints. The drive turbine was optimized using the in-house Computer-Aided Design Optimization (CADO) tool, using metamodel-assisted evolutionary algorithms to operate efficiently at lower mass flowrates while maintaining the required power. The optimized turbine achieved an 18.82% reduction in mass flow compared to the baseline. Stator blade modifications, necessitated by volute integration, improved power output by 11.7%. The optimized turbine stage was additively manufactured using Inconel-718. This work provided a robust framework for designing and manufacturing high-speed, high-temperature turbines to advance power-to-heat turboreactor technologies for the electrification of the energy-intensive process industry.