Multi objective optimization and probabilistic design on aircraft fuel system

The fuel system in an aircraft is the largest and the most important system. Designing a fuel system puts large demands on the engineers and therefore a computer software (a quantified morphological matrix) has been developed by Saab Aerosystems. The software is used as synthesis help during the conceptual phase and helps the designer to look through different concept solutions and minimizes the risks that wrong concepts will be chosen.

The main goal for this thesis is to develop and improve the quantified morphological matrix with a multi objective optimization framework and also build it out with a probabilistic approach for the different concepts. For deterministic optimization this was done with the weighted sum method which makes it possible to investigate different conflicting objectives and also presents the best possible combinations of the objectives. Using probabilistic design in multi objective optimization can be a complex mission and therefore the computer program Crystal Ball is used to be able to handle this kind of difficulties. The software uses a simulation type called Monte Carlo to simulate a model and to get useful probabilistic design analyses.

The results presented show that there exist several different concept solutions dependent on several factors as altitude and the weighting factors, which are used for the weighted sum method. With a probabilistic approach, the conclusion can be drawn that there are no differences of the concept solutions between the deterministic and the probabilistic optimizations. The concept solutions will be same regardless of distributions and the objectives calculated with the Monte Carlo method are the same as when calculated deterministically as a single objective

Author: Mihalyi, Levente

Source: Lulea University of Technology

Download Link: Click Here To Download This Report (PDF)

Reference URL: Visit Now

Leave a Comment