An experimental database on wall impingement of droplets and sprays has been created.
The investigations have been divided into different work package tasks focusing on single droplet impact [UB; ITS; ONERA; WUEK]; droplet chain impact [ITS; ONERA; WUEK]; mono disperse sprays [ITS; UB; WUEK]; and GDI injector (poly disperse) sprays [CUT; CU].
In the experiments wall temperature; surface structure; and backpressure as well as impact velocity; angle; and frequency have been varied.
They were carried out using different liquids; investigating large ranges of Capillary and Laplace numbers.
From images and high-speed films a classification of phenomenological impingement regimes could be achieved. In case of breakup regimes; detailed information on secondary droplet number; size; and velocity in a hemisphere around impact location was obtained from Phase-Doppler anemometry (PDA) measurements.
The collected comprehensive database is suitable to derive statistical models for droplet wall impingement from it.
Complementary; a code for 3D simulations of droplet impingement on cold and hot surfaces using a Volume-of-Fluid method was developed and applied to increase the understanding of physical processes [NTUA].
Furthermore; experiments of spray injection in a pressure chamber and optical engines as well were performed [CUT; CU]. From visualisations impingement phenomenology for different angles can be recognised. PDA measurements show secondary droplet properties and distributions.
The abbreviations in brackets [] used above refer to the corresponding project partners who performed the experiments and own the data: [CUT]: I. Denbratt; Chalmers University of Technology (S); [CU]: C. Arcoumanis; City University (UK); [ITS]: K. Dullenkopf; University of Karlsruhe (D); [NTUA]: G. Bergeles; National Technological University of Athens; [ONERA]: G. Lavergne; ONERA (F); [UB]: E. Cossali; University of Bergamo (I); [WUEK]: U. Renz; Aachen Univesity of Technology (D).
