Invited speakers

Monday, 12 June, 2023

Title: Unsteady Loads on Ground Vehicles: Testing with Real-Life Conditions

Dr. Daniela Heine, Institute of Aerodynamics and Flow Technology, Ground Vehicles Department,  DLR Göttingen

 Abstract: Testing of the aerodynamics of ground vehicles is mostly performed with steady wind conditions. However, real life is not steady. To which extent are the loads like crosswind forces and drag on trains and cars affected by gusts und turbulent flow conditions?

To give an answer to this question, the incoming flow of vehicles in operating conditions was investigated using a car equipped with measurement equipment on a test track in various driving scenarios. The results were analysed regarding the unsteady flow parameters like degree of turbulence and length of the dominant flow structures. To test the influence of these flow parameters on the loads of trains and cars, a wind tunnel was kitted up with a wing system with movable flaps which acts as gust generator. Using this gust generator the unsteady loads on trains and cars are investigated depending on the flow parameters and are presented here.

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Tuesday, 13 June, 2023

Title: "Simulation and active control of wake bi-modal switching"

Prof. A. S. Morgans, Department of Mechanical Engineering, Imperial College London, UK

Abstract: A new feature of wake flows behind blunt bluff bodies, identified only in the last decade or so, is wake bi-modality (or, more generally, wake multi-modality). This occurs when a wake undergoes random switching between different asymmetric positions, with the random interval between switches characterised by large timescales. Wake bi-modality is associated with enhanced drag, and the preferred wake asymmetric positions have been shown to be the result of laminar flow instabilities/bifurcations, with switching events triggered by flow disturbances. The large timescales and dependence on flow disturbances makes computational simulation challenging. We present simulations of wake switching events, insights into both how to simulate them and the wake switching process as well as active control strategies for suppressing them.  

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 Wednesday, 14 June, 2023

Title: "Coupling physics-based and data-driven models for the simulation of fluid/structure interaction: application to tire/liquid interactions modelling"

Dr. Thibault DAIRAY, Manufacture Française des Pneumatiques Michelin, France

Abstract: In a world of tire manufacturing becoming more and more competitive, modelling and simulation are major solutions to improve our product design at Michelin. In the R&D department, numerical simulation tools are developed and used daily to better understand and improve the performance of our future products. If numerical tools are of paramount importance to help decision making, high computational and implementation costs can slow down the virtual design process.

To accelerate the time-to-market of our product, a possible trade-off solution is to take advantage of existing physics-based simulation databases to build data-driven Reduced-Order-Models (ROMs). These simplified approximation models can then be used during the design process to quickly explore the solution space.

This talk will start with a broad overview of some applications at Michelin linked to the broad field of fluid mechanics: going from tire aerodynamics studies to non-Newtonian fluids simulations in rubber process manufacturing modelling. The second part of the talk will be focused on some recent studies aiming at coupling physics-based and data-driven ROMs for the simulation of tire/liquid interaction in the context of tire hydroplaning modelling.