Title:	Storage for multidisciplinary simulation of flows, acoustics, structures and coupled FSI
DNr:	NAISS 2024/6-197
Project Type:	NAISS Medium Storage
Principal Investigator:	Huadong Yao <huadong.yao@chalmers.se>
Affiliation:	Chalmers tekniska högskola
Duration:	2024-07-01 – 2025-07-01
Classification:	20306
Homepage:	https://huadong.m2.chalmers.se/projects/
Keywords:

Abstract

This project is proposed to apply for the storage for another computer-hour project on Tetralith, which includes three major branches. Brache 1 -- acoustics: Wind noise becomes dominant as automobiles driving at cruise speed (80-90 kph). A quiet driver environment is a contributing sales motivation in the sense of comfort, safety and quality. Wind noise is almost always undesired, in contrast to engine noise which in some cases provides useful feedback to the driver. Over time the engine noise has been reduced, and the relative wind noise contribution has increased. Wind noise will become even more pronounced in the future in regard to hybrid or fully electric propulsion. In product development, a predictive numerical method for wind noise is needed. For engine noise, there are well-established tools and methods available. However, when it comes to wind noise, many areas of Computational Aero-Acoustics are still active research areas, meaning that methods and tools are not so established and mature as those for aerodynamics. With a fundamental understanding of noise source generation, it will be possible to develop a set of design guidelines and virtual methods that can be used to evaluate, predict and optimize the behavior of typical exterior shapes used on automobiles. The techniques will be beneficial in the product development process, to predict problems already before a product has been built and reduce physical testing. This project branch aims to establish a fundamental understanding of how noise sources are created by external turbulence around automobile bodies and how the noise sources depend on geometrical complexity and flow speeds. Branch 2 -- flow dynamics: The project branch will advance the state of the art in nacelle design by smart use of various fidelity level aerodynamic modeling tools enabling fast iterations and down selection of nacelle geometries and locations. Wing/nacelle interference will be taken into account. This method will be validated by wind tunnel experiments with new and advanced wind tunnel models and measuring techniques. Branch 3 -- MDO (multidisciplinary design optimization) and FSI (fluid-structure interaction): Electrification of vehicles has a good momentum today. However, the energy consumption of electrified vehicles is not very much in focus, instead, in-efficient electrified vehicles are appreciated on the cost of more energy-efficient ICE vehicles. There is talk about a ‘nordic energy mix’, but still almost every single extra kWh of electric energy put in an electrified vehicle in Scandinavia must be generated by fossil fuels. This needs to come to an end when electrified vehicles become more and more common. The purpose of this project branch is to optimize the electric machine-gear package to find a system solution that has the highest efficiency, but still reasonable size. The hypothesis is that by a careful design of the gearbox, selection of more viscous oil, but still suitable to maintain the lifetime of the gear in combination with an adapted machine design will lead to important loss savings in the transmission of an electrified vehicle.