Facilitating advanced spectral element simulations of wall-bounded flows
Time: Thu 2025-10-23 10.15
Location: F3, Lindstedtvägen 26
Video link: https://kth-se.zoom.us/j/67397349774
Language: English
Subject area: Engineering Mechanics
Doctoral student: Ronith Stanly , Strömningsmekanik, FLOW
Opponent: Professor Sylvain Laizet, Imperial College, London, England
Supervisor: Professor Philipp Schlatter, Strömningsmekanik; Professor Stefano Markidis, Beräkningsvetenskap och beräkningsteknik (CST); Doctor Timofey Mukha, Computer, Electrical and Mathematical Sciences and Engineering Division, King Abdullah University of Science and Technology (KAUST), 23955-6900 Thuwal, Kingdom of Saudi Arabia.
QC 250930
Abstract
The overarching aim of this thesis is to enable accurate simulations of high-Reynolds-number wall-bounded flows, representative of those encountered in realistic engineering applications. Achieving this goal requires progress on several fronts, ranging from methodological developments to computational considerations and the application of simulations to relevant flow configurations.
First, advances are made in numerical techniques for scale-resolving simulations of wall-bounded turbulence. New methods are introduced that allow turbulent boundary layers to be simulated efficiently at arbitrarily high Reynolds numbers and sustained over long physical times. In addition, existing turbulence inflow generation approaches are assessed with particular emphasis on their suitability for aeroacoustic predictions, where a physically consistent representation of turbulent structures is essential.
Second, the ability of scale-resolving simulations to exploit emerging computing architectures is investigated. In particular, the sensitivity of such simulations to reduced-precision arithmetic, a feature increasingly common in modern high-performance computing hardware, is systematically evaluated. This provides insights into the accuracy–efficiency trade-offs that can be expected as computational platforms evolve.
Finally, the methods are applied to canonical but engineering-relevant test cases that combine fundamental physical interest with practical significance. Direct numerical simulations are carried out for flow over the Boeing speed bump and for a drone rotor at moderate Reynolds numbers. For the Boeing speed bump, a detailed analysis of boundary-layer dynamics is performed, providing new insights into the interaction between geometry-induced pressure gradients and turbulent structures. The drone rotor simulations, in turn, represent a first step toward applying scale-resolving methods to realistic aerodynamic configurations where both performance and noise are of interest.
Overall, the contributions of this thesis span algorithmic development, computational assessment, and application to canonical test cases, thereby laying the foundation for scale-resolving simulations of wall-bounded turbulence at conditions directly relevant to engineering design.