Search

Tire hydroplaning is a phenomenon that occurs when the tire is no longer able to evacuate water from the road due to excessive speed. A water layer will then be interposed between the tire and the road, reducing their contact surface and decreasing the tire''s ability to transmit forces. The purpose of this work is to analyse this loss of contact surface through the experimental point of view with real scale tests, which are perfectly suitable to understand the mechanisms. These tests consist in observing and then measuring the contact area of the tire with the ground in hydroplaning conditions through a measurement window. An investigation of the main factors engaged in hydroplaning situation is performed and the key parameters involved are identified. For a given tire, these surface losses are measured as a function of speed under different experimental conditions (inflation pressure, water level, tire wear, etc.). These results are then partially extended to the study of three other tires. [ABSTRACT FROM AUTHOR]

A reduction in air pollution is an essential step toward decreasing certain health risks in urban area populations. Road traffic is one source of this pollution and can be categorized into exhaust and non-exhaust emissions (NEE). Non-exhaust emissions include, but are not limited to, brake wear particles and Tire Road Wear Particles (TRWP). Emission Factors are often used to assess the share and the amount of vehicle exhaust and non-exhaust particles in the air. In this study, we developed an approach to measure the Emission Factors (EF) of tire Particulate Matter (PM). The approach is based an experimental method allowing for direct measurements in real conditions (on a vehicle on the road). The experimental set-up as well as the measurement protocol lead to a significant reduction in the classical biases of the on-road approach, which usually lead to a large over-estimation of the amount of PM 10 and PM 2.5 emitted by the tire. We observed that TRWP emissions correlate in time with the tire solicitation. A careful computation from the PM 10 and PM 2.5 collected by a real time particle counter enables an evaluation of the total amount of TRWP contributing to air pollution. The average results indicate an Emission Factor for PM 10 4.5 times lower than the EMEP guidebook value and 42 times lower for PM 2.5 . This discrepancy calls for further tests to confirm the results., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Frederic BIESSE reports financial support was provided by French Manufacture of Michelin Tyres., (Copyright © 2022 The Authors. Published by Elsevier B.V. All rights reserved.)

Since its discovery at the end of the 1950's, hydroplaning has been a matter of concern for drivers on wet roads because it can affect driver safety. Indeed, this phenomenon can lead to a complete loss of contact between the tire and the road caused by the layer of water that develops between them, resulting in a complete loss of longitudinal and lateral grip. Although the phenomenon of hydroplaning is about 60 years old, it is almost impossible to find any scientific estimation of how frequently vehicle accidents can be caused by hydroplaning, especially in Europe. To cover this gap, the well-known German In-Depth Accident Study (GIDAS) project has assisted to conduct a study. Thanks to GIDAS, it was possible to identify a sufficient number of cases on wet roads including a high accuracy of information about relevant parameters. With a physical analysis of all the cases, it was possible to compute the probability for an accident case to be in a full hydroplaning situation. This allowed for a precise estimate of the real importance of full hydroplaning situations on accident occurrence, which appears to be a much rarer accident cause than most drivers think., Competing Interests: Declaration of Competing interest The VUFO laboratory has been funded for this study by the Manufacture Française des Pneumatiques Michelin, Clermont Ferrand, France., (Copyright © 2020 Elsevier Ltd. All rights reserved.)