Active Control Turbocharging: Experimental Data and Theoretical Perspectives

Abstract

The present paper presents the results of many years of research into a new type of turbocharging technology, developed by the Turbomachinery Group of Imperial College in England: the Active Control Turbocharger (ACT). ACT is a turbocharger that consists of a system and method of operation which provide suitable inlet geometry throughout the exhaust gas period of the engine with which it is connected. In this way inlet geometry is adjusted in an active manner to the especially dynamic, high frequency characteristics of the exhaust flow which pass through the turbocharger turbine. The technology has been developed with a view to offer a new option in meeting with the ever increasing requirements as a result of the increasingly stringent emissions regulations, as well as the drivability requirements of users of internal combustion equipped vehicles. The present paper presents experimental results from the first prototype ACT and the results from a one-dimensional simulation of ACT on a Diesel engine, according to which ACT shows an increased capability to take advantage of exhaust gas energy of up to 7.5%, experimentally, while the theoretical model shows significant improvement of an ACT-equipped engine compared to a VGT engine of up to 30% in terms of power. For the same levels of power ACT appears to be capable of reducing the required engine capacity of the engine by 20% compared to the same initial VGT engine.