Experimental analysis of a water spray for the sensors cleaning at different injection pressures

New technologies are revolutionizing the automotive market, with innovation reshaping what it means to drive or be driven, as new vehicles are being introduced in the last years. Smart vehicles are forced to integrate various sensors, usually cameras, capable of allowing autonomous functionalities. Cameras, 360° surround-view parking assist systems, and Intelligent Advanced Driver Assistance Systems (ADAS) must be mandatorily installed on vehicles for rules issued by many countries. Those optical sensors can be partially or totally obscured by many environmental factors; thus, these sensors need to be adequately cleaned. The paper presents an experimental methodology to study water sprays used on vehicles under different injection pressure. A schlieren setup was realized and images were acquired with a high-speed C-Mos camera at a rate of 25,000 frames per second (fps) with an image window of 384 × 352 pixels. The camera was equipped with a 90 mm objective, f 1:2.8, resulting in a spatial resolution of 4.70 pixel/mm. The spray was analyzed for different injection pressure making interesting consideration about its behavior.