Towards Multi-Fidelity Simulations in the Context of the Virtual Engine

Abstract

Multi-fidelity simulations couple methods of different degrees of detailing levels and by extension also disciplines. The individual level of fidelity for a specific computational domain is chosen for the best compromise between accuracy, the potential to model effects, and computational costs.

Depending on the point of view, the term multi-fidelity simulation can be ambiguous towards the actual simulation goal and used methodology. Typically, the components of a system are divided into the involved disciplines, such as aerodynamics and structural mechanics, and each define their own domain of investigation. Those domains each include different discretization schemes, boundary conditions and solver methods. In order to allow coupling between those domains, an adequate description of the connections and interfaces is required.

The typical holistic engine analysis approaches such as preliminary design, cycle analysis, or performance computation are derived from a geometry-based description of the individual components. In contrast, a domain-based description of the simulation topology is introduced which is built upon ontologies. It serves as the foundation to couple different domains across disciplines and fidelity levels.

The current work focuses on the built-up of the description of 3D high-fidelity simulations' setup and coupling, especially on high-performance clusters, in light of a future connection with the lower fidelity levels. A distinction of general approaches of different multi-fidelity scenarios is pointed out within the context of gas turbine simulation. Current efforts in implementation of multi-fidelity simulations focus on strategies for zooming and on the other hand, the approach towards coupling of 1D network simulations of secondary air systems with CFD.