The decisions taken during the aircraft conceptual design stage are of paramount
importance since these commit up to eighty percent of the product life cycle costs. Thus
in order to obtain a sound baseline which can then be passed on to the subsequent
design phases, various studies ought to be carried out during this stage. These include
trade-off analysis and multidisciplinary optimisation performed on computational
processes assembled from hundreds of relatively simple mathematical models
describing the underlying physics and other relevant characteristics of the aircraft.
However, the growing complexity of aircraft design in recent years has prompted
engineers to substitute the conventional algebraic equations with compiled software
programs (referred to as models in this thesis) which still retain the mathematical
models, but allow for a controlled expansion and manipulation of the computational
system. This tendency has posed the research question of how to dynamically assemble
and solve a system of non-linear models. In this context, the objective of the present
research has been to develop methods which significantly increase the flexibility and
efficiency with which the designer is able to operate on large scale computational
multidisciplinary systems at the conceptual design stage.
In order to achieve this objective a novel computational process modelling method has
been developed for generating computational plans for a system of non-linear models.
The computational process modelling was subdivided into variable flow modelling,
decomposition and sequencing. A novel method named Incidence Matrix Method
(IMM) was developed for variable flow modelling, which is the process of identifying
the data flow between the models based on a given set of input variables. This method
has the advantage of rapidly producing feasible variable flow models, for a system of
models with multiple outputs. In addition, criteria were derived for choosing the optimal
variable flow model which would lead to faster convergence of the system. Cont/d.
| Identifer | oai:union.ndltd.org:CRANFIELD1/oai:dspace.lib.cranfield.ac.uk:1826/5070 |
| Date | January 2007 |
| Creators | Balachandran, Libish Kalathil |
| Contributors | Guenov, Marin D. |
| Publisher | Cranfield University |
| Source Sets | CRANFIELD1 |
| Language | English |
| Detected Language | English |
| Type | Thesis or dissertation, Doctoral, PhD |
| Rights | © Cranfield University, 2007. All rights reserved. No part of this publication may be reproduced without the written permission of the copyright holder. |
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