Drops, Jets and Films – their generation, stability, mutual interaction, interaction with their surroundings, as well as their associated transport phenomena with the ambient play a vital role in all aspects of our lives, countless industrial processes and indeed, constitute the natural lifeline not only of humans, but also of all living matter. Research abounds in all of the above-mentioned aspects and the aim of the proposed course is to fill this educational gap specifically for researchers in this domain; hence, the course addresses researchers at the graduate and post-graduate level. Typically, these researchers are coming from the disciplines of engineering, physics, mechanics, mathematics or chemistry, but it is not unlikely that also other natural sciences may be relevant, e.g., biology, medicine, and even forensics.
Research on drops, jets and films has a rich theoretical history, a somewhat younger experimental history and in recent times an indispensable anchor in numerical simulations, with its multitude of computational approaches. The lecturers of the proposed course have been selected to mirror this diverse set of methodologies. A further aim of the course is therefore to demonstrate the strengths and limitations of each method and to underline their complementarity. The course is particularly timely for a multitude of reasons, perhaps the most important being urgency. The COVID pandemic is just one example of how the interaction of aerosols with their environment reaches into all aspects of life, up to the societal-political level. However of equal if not stronger importance is the enormous economic impact that drops, jets and films have on our industrial world or on health issues, be it combustion, capillary flows, evaporation, coating, painting, liquid deposition, etc.
A further motivating factor for now addressing this topic is the growing maturity and capabilities in all approaches – theoretical, numerical and experimental, as well as the inter-disciplinarity of the subject which encompasses fluid mechanics with free surfaces, electrohydrodynamics, non-Newtonian fluid mechanics and heat and mass transfer, to mention a few topics relevant in the present course. A brief consideration of computing power, refinement of numerical schemes or the speed and resolution of imaging and illumination technologies make this self-evident. We are now offered a direct glimpse into the physics of these phenomena, which heretofore was unattainable. Why is this so important? This allows us to formulate and validate highly refined physical models of the hydrodynamic and thermodynamic processes involved, which are essential for improving predictive capabilities, as well as for development of ‘reduced’ highly powerful analytical models.
The proposed course attempts to address the above issues at various levels comprising historical retrospection, theoretical foundations, experimental and numerical methodologies, but also demonstrating advantages and disadvantages of different approaches through example research problems and solutions. These examples offered by the lecturers are to be complemented by discussion of individual challenges from participants, ideally in the form of poster presentations. An indication of the topical content is already given by the selected keywords: liquid interfaces, interfacial flow, hydrodynamic instabilities, drop impact, atomization. A more detailed description can be extracted from the list of individual lecture titles.