The appropriate mixing of a urea–water solution (UWS) with exhaust gases in a selective catalytic reduction system is crucial to efficiently reduce nitrogen oxides and diminish the deposition of liquid wall film. One of the methods to enhance the mixing of the UWS with the exhaust gases is a flash-boiling injection. Its positive effect has been linked with a reduced Sauter mean diameter (SMD) and improved evaporation, but the...

The collision of two or more liquid jets may provide considerable atomisation and efficient mixing of injected substances at the same time. This phenomenon is used, among others, in rocket engines, where the fuel and oxidiser are introduced separately and almost immediately mixed through self-impingement. Depending on the injection and operating conditions, diverse configurations of impinging jets are used, such as doublets,...

In the present study, a flow rig with optical access intended for spray investigations in exhaust system-relevant conditions was analysed in terms of flow and temperature in the spray area using numerical simulations. The operation of the rig was examined for a wide range of exhaust mass flow rates, temperatures and various forms of UWS (urea-water solution) spray plumes. The locations of the injector and thermocouple were verified....