The course CFD for Vehicle Aerodynamics is given in collaboration with Chalmers Professional Education
Vehicle aerodynamics (of road vehicles and trains) departments are using more and more CFD in their design process. Although steady RANS simulations are standard in most vehicle aerodynamics departments, time-dependent simulations such as LES and DES are better suited for unsteady flows . However, the application of these methods in vehicle aerodynamics is not easy due to large computational effort but also because the time-dependent simulations require more knowledge from the CFD engineer in all steps of the project, from choice of the appropriate technique, construction of the mesh, over performing the simulation to the analysis of the results.
There is large number of vehicle flows where time-dependent simulations are the only way of analyzing the problem because experimental techniques cannot provide realistic flow. Examples are influence of wind gusts on vehicles or overtaking and passage of vehicles. Another trend in vehicle aerodynamics is that CFD is not only used for prediction and explanation of flows but also for improvement of aerodynamic performance of vehicles. This is done using shape optimization and/or flow control. Both these techniques are being introduced in industry and they require that the CFD engineer has knowledge in application of these techniques.
The idea behind this course is to transfer the knowledge an the experience in these CFD techniques for vehicle aerodynamics from our research group (Vehicle Aerodynamics Laboratory) to other researchers and industrial users.
The course will give an introduction in how time-dependent techniques such as Large-Eddy Simulations (LES), Detached-Eddy Simulations (DES), Partially-Averaged Navies-Stokes (PANS) and unsteady RANS (URANS) can be used in vehicle aerodynamics. We will discuss differences between these techniques and give best practical guidelines for usage of each technique. We will show when each of the techniques could/should be used and how to use it. Questions such as:
- How to make an appropriate computational grid?
- What is the appropriate numerical scheme?
- How to initiate a simulation, run it, average and analyze the results of the simulation?
will be discussed.
After an introduction to these techniques, we will show how these techniques can be used for prediction of different aspects of vehicle aerodynamics flows. One important aspect of prediction of flows will be directional stability. We will show how these time-dependent techniques can be used to study flows around vehicles influenced not only to constant crosswinds but also wind gusts. We will present several different techniques for simulating flows under influence of atmospheric wind gusts. Beside the atmospheric wind gusts, participants will learn how to study influence of vehicles passing other vehicles or other objects such as platforms or tunnels.
Second part of the course will introduce recent development in aerodynamic shape optimization. Here we will present several different ways for multi-objective aerodynamic shape optimization of vehicles. Both optimization using surrogate models and automatic optimization algorithms will be discussed.
The third part of the course will discuss flow control and how time-dependent CFD approaches can be used to improve aerodynamic performance of vehicles. Both passive and active flow control will be discussed and participants will learn how CFD can be most efficiently used to introduce and optimize flow control devices.
ORGANIZATION OF THE COURSE
During the lectures we will discuss the theory and during the workshops we will learn how to prepare, run and analyze different time-dependent CFD simulations. Furthermore, MATLAB programs will be used for aerodynamic shape optimization. There will be a PC workstation for each participant at the workshops.
The price is 20,000 SEK (excl. VAT) which includes course material, lunches, course dinner, and coffee. For PhD students the fee is reduced to 15,000 SEK (excl. VAT).