Since over 25 years the Research Group has been involved in studies on the intake and exhaust components. Referring to this subject, many investigations have been developed, most of which using an original experimental facility that allows to study single devices and subassemblies of automotive intake and exhaust circuit, both under steady flow conditions and with a pulsating flow which reproduces the pressure pulses occurring in multi-cylinder engines.

Many experimental investigations developed in the past were referred to exhaust turbochargers, even if different intake and exhaust automotive components were also considered, such as manifolds, junctions, after-treatment devices (EGR systems, catalytic converters, particulate filters).

Besides, some theoretical aspects were taken into account, with particular reference to the development of performance predicting procedures under unsteady flow conditions. Within this frame, the circuit of the test facility was recently developed using GT-Power code in order to simulate I/E components performance (Fig.1). 

In recent years the attention has been focused on the application of turbocharging to automotive downsized gasoline engines, in conjunction with fully flexible valve control systems (VVA) and an optimised design of the intake and exhaust circuit. Usually a waste-gate valve is installed as turbocharger regulating system, consequently several investigations have been developed aimed at analysing the effect on steady and unsteady turbine performance and focused on pressure distribution along the turbine volute casing. 

Besides, investigation has been focused on compressor surge under steady and unsteady flow conditions and on heat transfer phenomena in turbochargers performing investigations under quasi-adiabatic condition.

Researches

• Silvia Marelli
• Massimo Capobianco

Laboratories

• Laboratorio di Motori a Combustione Interna

Publications

• O.Acton, M.Capobianco – “Il banco prova per gruppi turbosovralimentatori del laboratorio di Macchine di Genova” – XLI Congresso Nazionale ATI, Napoli, 1986.
• M.Capobianco, S.Marelli – “Turbocharger turbine performance under steady and unsteady flow: test bed analysis and correlation criteria” – 8th International Conference on Turbochargers and Turbocharging – I.Mech.E., London,  May 2006.
• S. Marelli, M. Capobianco, “Steady and pulsating flow efficiency of a waste-gated turbocharger radial flow turbine for automotive application”, Energy, vol. 36, p. 459-465, ISSN: 0360-5442, doi: 10.1016/j.energy.2010.10.019, 2011.
• S.Marelli, A. Misley, M.Ferrando, Experimental investigation in turbocharger compressors during surge operation, Proceedings of ASME Turbo Expo 2020, GT2020-15174, 2020.
• S. Marelli, G. Marmorato, M. Capobianco, Evaluation of heat transfer effects in small turbochargers by theoretical model and its experimental validation, Energy, Elsevier, Volume 112, 1 October 2016, Pages 264–272, doi:10.1016/j.energy.2016.06.067.