ID 290

Experimental Characterization of Water Injection and Strategies for Gasoline Engines

 

Abstract:

Water injection is a promising technology for high-efficiency gasoline engines to reduce carbon emissions and the risk of abnormal combustion. Different types of water injection have been investigated in an extensive experimental study, so both the low-pressure and high-pressure injection were analyzed fundamentally. The study contains multi-stream solenoid injectors for the port and direct injection. The experimental set-up started with an optical investigation of the spray breakup behavior by using a self-developed injection test bench in combination with a high-speed camera and light scattering based particle sizer. It was possible to analyze the dependency of injector type, injection pressure and the fluid itself on the spray parameters such as cone angle, penetration length and droplet size. In order to evaluate the differences also quantitatively, experiments on the mass flow rate and in a single cylinder engine followed. The engine’s design with both a port and a separate direct water injection will allow varying the injection strategy in its timing and duration under different load conditions. Knowledge of the water injection characteristics and an optimized strategy will increase the water efficiency as well as the engine’s performance.