Experimental investigation of drop impact onto a wetted wall of different liquids
Fuel mixture generation and emissions in modern combustion engines are influenced by the interaction of fuel spray droplets impacting onto lubricating oil films in the cylinder. A further influence on emissions is found in SCR DeNOx systems, in which urea-water solutions are injected into catalytic converters and impact onto existing liquid films of varying urea concentration. In both cases the drop/wall interaction is affected by the fact that the drop and the liquid film are different liquids and may exhibit different degrees of miscibility. The composition of secondary drops resulting from the impingement and the state of the liquid film influence significantly the mixture preparation in either the engine or the converter. It is therefore of importance, also for the correct simulation of this physical phenomenon, to understand the mechanisms of spray impact with differing liquids.
The subject of the proposed study is an experimental investigation of the composition/dilution of the secondary droplets and the remaining wall film. The goal is to better understand the fluid distribution after the drop impact.
The task includes
• Preparing the experiments, preliminary tests of dyes
• Conducting experiments: drop impact onto a wetted wall of different liquids
• Analysing the experimental data
• Documentation and presentation of the results
Pre-requisites or requirements for the project
- Interest in experimental work
- MATLAB (not mandatory)
Recommended Literature and preparation
A. L. Yarin, \Drop impact dynamics: splashing, spreading, receding, bouncing,“ Annu. Rev. Fluid Mech. 38, 159-192 (2006).
S. T. Thoroddsen, T. G. Etoh, and K. Takehara,”High-speed imaging of drops and bubbles,” Annu. Rev. Fluid Mech. 40, 257-285 (2002).
I. V. Roisman and C. Tropea, “Impact of a drop onto a wetted wall: description of crown formation and propagation,“ J. Fluid Mech. 472, 373-397 (2002).
R. Rioboo, C. Bauthier, J. Conti, M. Voue, and J. De Coninck, “Experimental investigation of splash and crown formation during single drop impact on wetted surfaces,” Exp. Fluids 35, 648-652 (2003).
G. E. Cossali, A. Coghe, and M. Marengo,”The impact of a single drop on a wetted solid surface," Exp. Fluids 22, 463-472 (1997).
|Project available until||end of Aug 2018|