This paper presents a comparison study of the required thermal management of the open and closed circuit
hydraulic hybrid system. The hydraulic and thermal system behaviour of the open and closed circuit systems
were successfully modelled using a lumped parameter approach. The temperature of both open and closed circuit
systems have been compared using different cooling conditions based on the UDDS driving cycle. The
simulation results show that the open circuit systems have the potential to require smaller heat exchangers as
compared to closed circuit systems. In addition, the open circuit system consumes less power from the prime
mover and incorporates a smaller charge pump.

Functional safety standards define safety levels based metrics calculated from reliability of a safety function
components. However, calculated metrics rely on assumptions suitable for electronic components, and do not
reflect correctly reliability of hydraulic components. Such components are better described by a Weibull
distribution, but due failure rate not being constant on time, it is more complex to determine metrics and are not
considered in functional safety standards. This paper offers a method of how to consider such reliability models,
and study the behaviour of a safety function by consideration of Weibull distribution on hydraulic valves.

An overview to the performed analysis and lessons-learnt from flight control & hydraulic designers’ perspective on a condition monitoring (CM) concept for helicopters (H/C) hydraulic pump is given. A selection of already performed studies on condition monitoring applications for hydraulic pumps is discussed and the main obstacles in the CM implementation process for H/C hydraulic pumps are drawn from it as lessons-learnt. It is considered unavoidable to enter the CM concept by a data collecting and processing phase. Thanks to the CM hybrid algorithm continuous maturity improvement by data feeding, the obtained in-service data will be then directly used to identify the failure in real-time. In parallel, the data trend evolution analysis should allow to decide if it can be used also as a predictive element into the CM system for the dedicated failure mode.

Maximum and fatigue loads determine the dimensioning of rotor blades for wind turbines. Due to the large inertia of blades with weights above 35 tons, the reduction of loads via dynamic pitching of blades has a limited effect. Known from aviation, the trailing edge flaps (TEF) have been subject of recent research in wind energy, however there is no commercial solution for a practical implementation till now. The paper presents the development of a novel solution for trailing edge flaps. Experiments carried out at a test section of a 44 m rotor blade are evaluated.