A Parametric Analysis of a Turbofan Engine with an Auxiliary Bypass Combustion Chamber – The TurboAux Engine

A parametric study of a novel turbofan engine with an auxiliary combustion chamber, nicknamed the TurboAux engine is presented. The TurboAux engine is conceived as an extension of a low-bypass turbofan engine with an auxiliary bypass annular combustion chamber around the core stream. The study presented in this thesis is motivated by the need to facilitate clean secondary burning of fuel at temperatures higher than conventionally realized, from air exiting the low-pressure compressor. The parametric study starts by analyzing the turbojet engine and its performance with and without an afterburner segment attached. Following that, the conventional turbofan and its mixing counterpart are studied, also with and without an afterburner segment. Then, a simple optimization analysis to identify optimal ‘fan’ pressure ratios for a series of conventional low-bypass turbofan engines with varying bypass ratios (0.1 to 1.5) is done. The optimal fan pressure ratios and their corresponding bypass ratios are adapted to study the varying configurations of the TurboAux engine. The formulation and results are an attempt to make a case for charter aircrafts and efficient close-air-support aircrafts. The results yielded increased performance in thrust augmentation, but at the cost of a spike in fuel consumption. Further analysis is required to determine the application of the TurboAux