Hydroplaning is a phenomenon that occurs when a layer of water between the tire and pavement pushes the tire upward. The tire detaches from the pavement, preventing it from providing sufficient forces and moments for the vehicle to respond to driver control inputs such as breaking, accelerating and steering. This work is mainly focused on the tire and its interaction with the pavement to address hydroplaning. Before using a full-scale tire model, interactions of the tread block with a specific surface is studied. To do so, several mechanical tests such as uniaxial, biaxial, planar (shear), and DMA are conducted to predict the hyper-viscoelastic properties of the rubber. Using multi-scale modeling techniques, the friction coefficient between the tire and pavement, for wet conditions, is characterized via developing 2D and 3D model representing the rubber tread interacting with the rough surface.
Using a tire model that is validated based on results found in the literature as well as in-house experimental data, fluid-structure interaction (FSI) between the tire-water-road surfaces are investigated through two approaches. In the first approach, the coupled Eulerian-Lagrangian (CEL) formulation was used. The drawback associated with the CEL method is the laminar assumption that the behavior of the fluid at length scales smaller than the smallest element size is not captured. To improve the simulation results, in the second approach, an FSI model incorporating finite-element methods and the Navier-Stokes equations for a two-phase flow of water and air, and the shear stress transport k-ω turbulence model, was developed and validated, improving the prediction of real hydroplaning scenarios. The improved FSI model was applied to hydroplaning speed and cornering force scenarios. In addition, tire contact patch length was calculated using the developed FSI model and was compared to the results obtained from the intelligent tire. / Doctor of Philosophy / Hydroplaning is a phenomenon that occurs when a layer of water between the tire and pavement pushes the tire upward. The tire detaches from the pavement, preventing it from providing sufficient forces and moments for the vehicle to respond to driver control inputs such as breaking, accelerating and steering. Hydroplaning as well as low skid resistance are considered as the main factors leading to traffic accidents. This work is mainly focused on the tire and its interaction with the pavement to address hydroplaning. Different factors involve in the hydroplaning phenomenon such as water film thickness, tire pressure, tire tread pattern, tire tread depth, vehicle speed and pavement texture. Before using a full-scale tire model, interactions of the tire tread with a specific surface is studied. To do so, several mechanical tests are conducted to predict the hyper-viscoelastic properties of the rubber. Using a single scale methodology is not capable to obtain the sufficient information regarding the effect of roughness on the friction. As a result, using multi-scale modeling techniques, the friction coefficient between the tire and pavement, for wet conditions, is characterized via developing 2D and 3D model representing the rubber tread interacting with the rough surface.
Since in the hydroplaning problem, a solid structure and a fluid domain are in interaction, such a problem considered as a fluid-structure interaction (FSI) problem. In this work, the FSI between the tire-water-road surfaces are investigated through two approaches. To improve the simulation results, an FSI model incorporating finite-element methods and the Navier-Stokes equations for a two-phase flow of water and air, and the shear stress transport k-ω turbulence model, was developed and validated, improving the prediction of real hydroplaning scenarios. In addition, tire contact patch length was calculated using the developed FSI model and was compared to the results obtained from the intelligent tire.
Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/111770 |
Date | 17 March 2021 |
Creators | Nazari, Ashkan |
Contributors | Mechanical Engineering, Taheri, Saied, Kennedy, Ronald H., Ferris, John B., Flintsch, Gerardo W., Sandu, Corina |
Publisher | Virginia Tech |
Source Sets | Virginia Tech Theses and Dissertation |
Detected Language | English |
Type | Dissertation |
Format | ETD, application/pdf |
Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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