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The operation of a conventional passenger car is characterised by increasing or maintaining the kinetic energy, when accelerating or cruising the vehicle, and reducing the kinetic energy by using the brakes. While the energy taken by the friction brakes to slow the vehicle is dissipated into heat, the introduction of Kinetic Energy Recovery Systems (KERS) has permitted the recovery of part of the braking energy. This reduces the amount of energy needed from the internal combustion engine (ICE). The contribution reviews the latest developments in electric KERS (E-KERS), with emphasis to round trip efficiency wheels to wheels and electrification of the powertrain. The contribution considers the opportunity to connect the E-KERS traction battery to other electric machines, such as an electrically assisted turbocharger (E-TC) connected to a motor/generator unit, or an electric water pump (EWP), to further optimise the vehicle operation.

The paper proposes a performance prediction method at design and off design values of mass rate and rotational speed for a low pressure ratio (2.2:1) centrifugal compressor capable of rotating at speeds up to 90000 r.p.m. The procedure employed consists of combining selected losses obtained from semi-empirical equations to construct an overall picture of efficiency of the compression process. The estimated performance of a radial centrifugal compressor with splitter blades was compared with experimental results covering wide range of the performance map, the achieved level of agreement was approximately within 4% from measurements. It should be mentioned however that the proposed method does not describe the internal aerodynamic effects occuring, it does however isolate some important variables and then relate them to the total pressure loss across the stage.

The work presented in this paper is concerned with the development of a performance prediction method for centrifugal pumps. Many formulae that have been used to predict pumps likely performance are based on expressions developed originally for centrifugal compressors, these were modified for pumps by removing the compressibility flow effects. Additional pump loss correlations were re-written and directly applied to typical pump geometries. Experimental performance measurements of seven centrifugal rotors have been compared with analytical predictions using the proposed method, the results were encouraging.