Supercharging system behavior for high altitude operation of an aircraft 2-stroke Diesel engine

Abstract

Different studies on both 2- and 4-stroke engines have shown how the choice of different supercharging architectures can influence engine performance. Among them, architectures coupling one turbocharger with a mechanical compressor or two turbochargers are found to be the most performing in terms of engine output power and efficiency. However, defining the best supercharging architecture for aircraft 2-stroke engines is a quite complex task because the supercharging system as well as the ambient conditions influence the engine performance/efficiency. This is due to the close interaction between supercharging, trapping, scavenging and combustion processes. The aim of the present work is the comparison between different architectures (single turbocharger, double turbocharger, single turbocharger combined with a mechanical compressor, single turbocharger with an electrically-assisted turbocharger, with intercooler or aftercooler) designed to supercharge an aircraft 2-stroke Diesel engine for general aviation and unmanned aerial vehicles characterized by a very high altitude operation and long fuel distance. A 1D model of the engine purposely designed has been used to compare the performance of the different supercharging systems in terms of power, fuel consumption, and their effect on trapping and scavenging efficiency at different altitudes. The analysis shows that the engine target power is reached by a 2 turbochargers architecture; in this way, in fact, the cylinder filling, and consequently the engine performance, are maximized. Moreover, it is shown that the performance of a 2 turbochargers architecture performance can be further improved connecting electrically and not mechanically the low pressure compressor and turbine (electrically-assisted turbocharger). From an energetic point of view, this system has also proved to be particularly convenient at high engine speed and load, because it is possible to extract power from the electric turbocharger without a penalty on specific fuel consumption.


Tutti gli autori

  • Carlucci A.P. , Ficarella A. , Laforgia D. , Renna A.

Titolo volume/Rivista

ENERGY CONVERSION AND MANAGEMENT


Anno di pubblicazione

2015

ISSN

0196-8904

ISBN

Non Disponibile


Numero di citazioni Wos

Nessuna citazione

Ultimo Aggiornamento Citazioni

Non Disponibile


Numero di citazioni Scopus

9

Ultimo Aggiornamento Citazioni

22/04/2018


Settori ERC

Non Disponibile

Codici ASJC

Non Disponibile