Modelling and simulation of the Water Enhanced Turbofan concept
Typ
Examensarbete för masterexamen
Master's Thesis
Master's Thesis
Program
Mobility engineering (MPMOB), MSc
Publicerad
2024
Författare
Herbertsson, Filip
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
The aviation industry needs to reduce its climate impact. The Water Enhanced Turbofan (WET) is a new engine technology that could reduce the climate impact from aviation with regards to carbon dioxide (CO2 ) emissions, nitrogen oxides (NOx ) emissions and contrail formation. In the WET cycle, water is injected into the combustion chamber, which lowers the formation of NOx -gases. The water also increases the thermodynamic efficiency of the turbines, and is collected through a set of heat exchangers so that it can be pumped back into the combustion chamber.
If more water is collected than what was injected, the exhaust stream will contain less water that has the potential to produce contrails.
In this work, a WET cycle engine and the components it consists from are modeled, based on a reference engine from previous Chalmers research and the most recent WET cycle concept from MTU Aero Engines. The concept engine is analysed through selected cycle design parameters, as well as through generalized geometric parameters (GGP) of the heat exchangers. The design point is optimized with respect to specific fuel consumption (SFC), and the benefits of the water injection are analysed.
It is estimated that, by careful selection of cycle parameters, CO2 -emissions can be reduced by more than 7% and NOx -emissions can be reduced by more than 85%. This is in fair agreement with the benefits that MTU Aero Engines predicts. Limiting factors include the weights of the WET cycle components, the size of the engine as well as the temperature that the low pressure turbine (LPT) can handle. It is proposed that, in order to obtain further benefits, other cycle parameters should be analysed such as the overall pressure ratio (OPR) and the amount of cooling flow.
Further, to remove the limit of LPT temperature, the LPT could be cooled by air from the compressor stages.
Beskrivning
Ämne/nyckelord
Water Enhanced Turbofan , CO2 emissions , NOx emissions , cycle optimization , GESTPAN , modelling , simulation