Automotive side mirror surface contamination

Abstract

With the increased use of Advanced Driver Assistance Systems (ADAS) in modern cars, the  field of surface contamination saw a resurgence. To keep the various sensors working properly it is of utmost importance to keep them clean and free of contamination. One way to achieve this is to ensure they are mounted in areas where they can be kept free of water droplets that can cause issues themselves, or by depositing contaminants that they are carrying. Current research focuses on the resulting contami- nation pattern after a drive or test on the car, this thesis however aims to see whether state-of-the-art Particle Image Velocimetry (PIV) techniques can be used to track the water droplets themselves, and with it open up new ways of researching surface contamination. To achieve this two experiments were performed. The first one was a simple experiment to see whether the droplets are being able to be imaged with the PIV cameras. The second experiment introduced a car side mirror model to the flow and used the Shake-the-Box (STB) algorithm to track the individual water droplets. Both of these ex-periments were successful, and showed that this combination of water droplets and STB PIV has great potential for being used in surface contamination research. The main issues found were with experi-mental setups, especially in the windtunnel. As the droplets do not follow the airflow accurately, extra care needs to be taken to ensure the droplets are operating at the right conditions, and are present at the measurement domain. The actual behaviour of the droplets as tracked by the STB algorithm, seems to be accurate with respect to the expectations indicating that the tracking of the droplets is accurate. Further research should try to increase the scale of the experiments, and/or introduce contaminants to the droplets to see how, if at all, this affects the traceability of the droplets.