Design and testing of an electro-mechanical injection system with multiple nozzles for a high-pressure fluid

Considering the concern of the European community about traffic safety in terms of road deaths and injuries, a major role is given to the phenomenon of aquaplaning, which consists of a loss of traction caused by a layer of water accumulated between the vehicle wheels and the road surface. Facing this issue, different OEMs and private companies are developing vehicle sensors and add-ins to reach the ambitious goal of zero road deaths by 2050 imposed by the European Community: considering this scenario, the EasyRain company has stood out from all the others. EasyRain has developed an innovative effect-based virtual sensor able to detect whether or not the occurrence of aquaplaning is affecting vehicle stability: this is the Digital Aquaplaning Information (DAI) sensor. The company has also taken a step forward by developing the first active safety system able to restore the control of the vehicle when in dangerous low-grip conditions by spraying a pressurized jet of windshield washer fluid in front of the vehicle's front tires to open the water layer: this is the Aquaplaning Intelligent Solution (AIS) platform. The AIS hardware platform has a relatively easy configuration, as it is made of a pressurizing system, an accumulator system, and an injection system: the injection system is that assembly that is triggered by the DAI sensor when traction control needs to be restored. To guarantee that the functioning of this injection system is satisfactory in terms of prompt response to danger, the valve system devoted to the opening of the liquid flow must be carefully optimized. An industrial indirect-acting solenoid valve is actually mounted into the AIS platform, but this is not the solution that best fits the type of application: for this reason, it has been decided to develop an EasyRain in-house solution focused on fulfilling all the AIS system requirements in terms of packaging, functioning and performance. The topic of this master thesis will be the design and validation process of a new direct-acting solenoid valve that can be mounted on the new generation of AIS platforms. The first proposed valve concept is a GDI-injection-system-inspired needle valve, which has been tested on a test bench to evaluate the timing of the switching cycle and the ground force exerted on the ground. The results obtained from this test session have commenced an iterative re-design and optimization process aimed at identifying the best valve configuration and sealing solution: this process has been supported by test bench sessions, FEM and modal analyses, and CFD simulations. At the end of the first phase of the re-design and validation process, which is described in this work, it has been identified an upside-down functioning working together with an o-ring sealing that has given comforting results, even if not all the targets have been successfully met. The second phase of the study process, which is not discussed here, will focus on refining the selected solution and resolving the issues encountered during the test bench sessions. In particular, attention will be paid to the packaging optimization and the substitution of some components to fulfill all the standards typical of an automotive application, toward the final target of industrialization of the AIS platform as an effective ADAS system.