The role of small hydropower is becoming increasingly important on a global level. Increasing energy demand and environmental awareness has further triggered research and development into sustainable low-cost technologies. In developing countries, particularly in rural areas, the possibility of local power generation could considerably improve living conditions. With this in mind, the development of a next generation low-head hydropower machines was subject of investigation in the EU-project HYLOW. Being part of the research lines of that project, this thesis presents a numerical modelling...