Abstract: Fluid being pumped by rotary piston/lobe pumps is prone to fluid cavitation particularly at the leading and trailing edges of the rotor.A rotor 10 comprises a generally cylindrical rotor hub portion 108 formed with two piston wing portions 110, 111. The piston wing portions 110, 111 are disposed transversely of the axis 13 on a substantially flat surface 112 of the hub portion 108. Extending from the surface 112 coaxially with axis 13, and disposed radially within the rotor hub portion 108, is a tubular portion 114 through which the end of shaft 15 passes when the rotary pump assembly is in an assembled state.Each piston wing portion 110, 111 is formed with a sinuous curved leading face region 113 and a sinuous curved trailing face region 115.The radially outermost (relative to the rotor axis) region of the leading face region 113 is formed with a leading curved edge part 116 and the radially outermost region of the trailing face region is formed with a trailing curved edge part 118.

Abstract: A heat flow transducer comprises one or more thermoelectric cooler (TEC) devices mounted in a core of heat resistant material which is subjected to the heat flow to be measured. Multiple TECs are thermally in parallel and electrically in series.