Preface to special issue on the dynamics of thin liquid films

A detailed understanding of flows in thin liquid films is important for a wide range of modern engineering processes. This is particularly so in chemical and process engineering, where thin liquid films are encountered in heat-and-mass-transfer devices (e.g. distillation columns and spinning-disk reactors), and in coating processes (e.g. spin coating, blade coating, spray painting and rotational moulding). In order to design these processes for safe and efficient operation it is important to build mathematical models that can predict their performance,
to have confidence in the predictions of the models, and to be able to use the models to optimise the design and operation of the devices involved. Thin liquid films also occur in a variety of biological contexts, including the thin liquid linings of the airways in the lung and the thin tear films that coat the eyes, and greater understanding of these films should lead to improved treatment of diseases in these organs.