Session: Poster Session

Paper Number: 162857

Aerothermal Design and Meta-Model Assisted Optimization of High-Speed Drive Turbine 

This work explores the development of a high-speed drive system for scaled-down electrified shockwave turboreactors tailored to the experimental laboratory pilot unit requirements. With shockwave turboreactors operating at extremely high rotational speeds and elevated environmental temperatures, a direct electric motor drive is not feasible due to thermal limitations. To address this, a drive turbine is proposed as an alternative for providing power to the turboreactor, specifically adapted to the limitations of small-scale operation. A traditional design approach, consisting of a preliminary 0D, 1D, and detailed 3D design, was conducted, incorporating design adjustments imposed by manufacturing constraints. Computational Fluid Dynamics (CFD) simulations further refined the design, and additive manufacturing (AM), using Inconel-718, was selected for production, imposing additional constraints that adversely impacted turbine performance. The drive turbine was optimized using the in-house Computer-Aided Design Optimization (CADO) tool, which employed a meta-model-assisted differential evolution optimization algorithm to achieve efficient operation at lower mass flow rates while maintaining the required power. The optimized turbine achieved an 18.82% reduction in mass flow compared to the baseline, while stator blade modifications, necessitated by volute integration, improved power output by 11.7%. The drive system configuration necessitated a new volute design, and the volute design criteria were discussed. The impact of flow angle distribution, incidence angles, and the trade-offs between design complexity, manufacturability, and performance were investigated, highlighting a reduction in efficiency caused by the volute. Microscopy and profilometry inspections of the manufactured components assessed the impact of manufacturing constraints. A key challenge in laboratory facilities, the limited availability of pre-heated mass flow, was addressed by optimising the drive turbine to operate efficiently at lower mass flow rates. The multidisciplinary design process validated the feasibility of the drive turbine concerning strength, quality, and performance, demonstrating a practical solution for driving high-speed micro-turbomachines in high-temperature environments.

Presenting Author: Rejish Lal Johnson Von Karman Institute for Fluid Dynamics

Presenting Author Biography: Rejish Lal Johnson is a PhD candidate at the von Karman Institute for Fluid Dynamics, Belgium, in collaboration with Ghent University. His research focuses on the design and optimization of turbomachines using CFD, as well as aerothermal chemical reactor design and realization using additive manufacturing. He previously worked as a CFD Simulation Analysis Engineer at Volvo Group Trucks Technology, Sweden and completed his master’s thesis at Ariane Group, Munich. His expertise lies in fluid dynamics simulations, and he has contributed to key projects in the chemical, automotive and aerospace sectors.

Authors:

Rejish Lal Johnson Von Karman Institute for Fluid Dynamics
Nikolaos Rafail Lotsios von Karman Institute for Fluid Dynamics
Mike Bonheure Ghent University
Johan Prinsier Von Karman Institute for Fluid Dynamics
Mohamed Hassanine Aissa Von Karman Institute for Fluid Dynamics
Kevin M. Van Geem Ghent University
Tom Verstraete Von Karman Institute for Fluid Dynamics