The research includes mainly development of rotating machines based on high-speed technology and various applications related to them. The applications are e.g. organic Rankine cycles (ORC), compressors, pumps, gas turbine processes, and refrigeration processes. Turbochargers of reciprocating engines are also included in the research. The research concentrates mainly on process design and calculations including process components, as well as development of rotating machines including also cooling of electric machines. The work also includes measurements and processing measured data. The aim is to improve the energy efficiency and reliability of rotating machines and processes related to them by considering manufacturing, maintenance and economical aspects as well.