Some implementations of this invention relate to energy systems and more particularly to rotating componentry enabling shaft work, propulsion drive, electric power generation, jet propulsion and/or thermodynamic systems related to aerothermodynamic thrust and shaft power, waste heat recovered shaft power, ventilation, cooling, heat, pressure and/or vacuum generating devices. Some implementations pertain to the art of vane assemblies for eccentrically placed rotating partial admission compressors and expanders that may either be used together or in conjunction with other mechanical, electrical, hydraulic and/or pneumatic machineries. Some implementations further relate to fluid energy recovery mechanical devices, targeting the field of gas turbine engines, internal combustion engines, furnaces, rotary kilns, coolers and refrigeration rotary components and/or expansion nodes. Other implementations are described.