Road vehicle aerodynamics are primarily focused on developing and modeling performance at steady-state conditions, although this does not fully encompass the entire operating envelope. Considerable vehicle acceleration and deceleration occurs during operation, either because of driver input or from transient weather phenomenon such as wind gusting. With this considered, high performance road vehicles experience body acceleration rates well beyond ±1G to navigate courses during efficient transition in and out of corners, accelerating from maximum straight-line speed to manageable cornering speeds, and then back to maximum straight-line speed. This dissertation aims to answer if longitudinal acceleration is important for road vehicle aerodynamics with the use of transient Computational Fluid Dynamics (CFD) to develop a method for obtaining ensemble averages of forces and flow field variables. This method was developed on a simplified bluff body, a channel mounted square cylinder, achieving acceleration through periodic forcing of far field velocity conditions. Then, the method was applied to an open-source road vehicle geometry, the DrivAer model, and a high performance model which was created for this dissertation, the DrivAer-GrandTouringRacing (GTR) variant, as a test model that generates considerable downforce with low ground proximity. Each test body experienced drag force variations greater than ±10% at the tested velocities and acceleration rates with considerable variations to flow field distributions. Finally, an empirical formulation was used to obtain non-dimensional coefficients for each body from their simulated force data, allowing for force comparison between geometries and modeling of aerodynamic force response to accelerating vehicle conditions.
|Commitee:||Jacobs, Donald, Noras, Maciej, Smith, Stuart, Tkacik, Peter|
|School:||The University of North Carolina at Charlotte|
|School Location:||United States -- North Carolina|
|Source:||DAI-B 79/09(E), Dissertation Abstracts International|
|Subjects:||Fluid mechanics, Aerospace engineering, Mechanical engineering|
|Keywords:||Added mass, Bluff body, CFD, Inertial coefficient, Road vehicle aerodynamics|
Copyright in each Dissertation and Thesis is retained by the author. All Rights Reserved
The supplemental file or files you are about to download were provided to ProQuest by the author as part of a
dissertation or thesis. The supplemental files are provided "AS IS" without warranty. ProQuest is not responsible for the
content, format or impact on the supplemental file(s) on our system. in some cases, the file type may be unknown or
may be a .exe file. We recommend caution as you open such files.
Copyright of the original materials contained in the supplemental file is retained by the author and your access to the
supplemental files is subject to the ProQuest Terms and Conditions of use.
Depending on the size of the file(s) you are downloading, the system may take some time to download them. Please be