On Optimisation of Environmentally Friendly Aircraft Engine Cycles

Abstract

In this work, the Techno-economic Environmental Risk Analysis framework, a multidisciplinary optimisation tool developed by Cranfield University, is utilised in conjunction with an in-house optimiser to carry out aircraft engine cycle optimisation processes. The central point here is the evaluation of the capabilities of the in-house optimiser for performing this type of optimisation processes. Simplifying hypotheses are thus considered when both defining the aircraft flight trajectory and modelling the different engine configurations analysed. Accordingly, several optimum engine cycles minimising separately three objective functions, (i) specific fuel consumption in cruise, (ii) fuel burned, and (iii) oxides of nitrogen emitted, are determined. The cycle optimisation processes carried out yield results reflecting the general trends expected when optimising according to these objective functions. It follows then that the in-house optimiser is suitable for carrying out gas turbine power plant optimisation processes. It is expected that this optimiser be utilised in future for both optimising the preliminary design of gas turbine engines and determining optimum and "greener" aircraft engine cycles.

Theoretical Optimal Trajectories for Reducing the Environmental Impact of Commercial Aircraft Operations

“…An integral part of Hephaestus constitutes the emissions prediction model described in , which follows an approach based on the use of a number of stirred reactors for modeling combustion chambers and estimating the level of pollutants emitted from them. Additional details of these computational models can be found in and Celis (2010).…”

“…Most important optimization methods can be grouped under three broad categories (Schwefel, 1981): (1) hill climbing methods (direct search methods, gradient methods and Newton methods); (2) random search methods; and (3) evolutionary methods. A detailed review of these methods can be found in Celis (2010).…”

Techno economic and environmental assessment of wind assisted marine propulsion systems

“…To predict the NOx and CO 2 emissions from the gas turbine power plant at different operating conditions, an in-house emissions prediction model was used. The model utilises the stirred reactor method for emission predictions and produces emission indices (Celis, 2010).…”

“…The simulated reference point for the powerplant has been based on published data of existing commercial gas turbines and are listed in Table 2. The emissions (CO 2 and NOx) for the fuel burnt through the gas turbine was predicted using an in-house emission prediction software (Celis, 2010).…”

Life cycle greenhouse gas analysis of biojet fuels with a technical investigation into their impact on jet engine performance

“…An elaborate stirred reactor model was adopted and used to computationally quantify NOx attributable to each of the Bio-SPKs, as suggested by earlier studies [35,36,43,44]. Emission indices Microalgae SPK and Jatropha SPK respectively.…”