AIRCRAFT CONCEPTUAL DESIGN USING MULTIOBJECTIVE OPTIMISATION

Abstract

Once the market research has been completed and requirements for a new aircraft have been define, the conceptual
design phase is launched. During the conceptual design phase, designers have the goal of defining and investigating a number
of alternative solutions for which optimisation tool are seldom used. Now a day, design is not limited to single objective
optimisation but expanding to multi-objective optimisation. In the aircraft conceptual design using optimisation, requires modal from
the various disciplines such as, structure, aerodynamics, propulsion and control which leads to the multidisciplinary design. In
this particular study, aircraft which has short range, low altitude and short take-off and landing are considered for which
Structure modal, weight modal and aerodynamic modal are prepared for the optimisation purpose. In addition, complete
mathematical modal are prepared, which represent the final objective statement, constrain, and fixed parameter and design
variables which is used for the design of aircraft used for fire-fighting or agriculture spraying. For study, all the basic terms
which are related to aircraft design are briefly discussed. Main objective of the study is to understand conceptual
design of the aircraft with the use of multi-objective and multi disciplinary optimisation. During the conceptual design, tradeoff between multi disciplinary and multi-objectives is occurred such as aircraft wing loading, wing aspect ratio, payload, takeoff and landing distance. With the use of direct search domain algorithm various design objective are optimise simultaneously.
Maximise the payload and minimise the take-off distance, minimise aircraft wing weight, minimise the wing aspect ratio and
minimise the wing loading are consider as a multi-objective optimisation in further design. In the aircraft conceptual design, wing
is the most important part of the aircraft design which is related to multidisciplinary like structure, aerodynamics and control. That‗s
why in the study, wing is the main design variable. Finally, we are designing the aircraft at conceptual level using multiobjective optimisation and compare the value with each set of multi-objective optimisation result.