General Parameters Optimum Design Of Tiltrotor Aircraft

The selecting of general parameters is a complex problem including many different disciplines. During the preliminary design of tiltrotor aircraft, the suitable optimization model must be formulated in terms of the design objectives. The general parameters design optimization of tiltrotor aircraft is completed based on effective engineering numerical methods and optimization tactic. The satisfied solutions can be obtained and are prepared for detail designs.Because the design of tiltrotor aircraft has unfavorable factors, such as long cycle, low efficiency, and complexity of analysis model, ant colony algorithms is introduced to solve the issue. As a new swarm intelligence algorithm, ant colony algorithm has the merits of global superiority, high efficiency, robustness, and successfully applied in many engineering problems. In this thesis, the aerodynamic model of tiltrotor aircraft is established by numerical methods. The flight performance and the weight of tiltrotor aircraft are calculated on this basis. Ant colony algorithms based on continuous space is used for general parameters optimization of tiltrotor aircraft. The design variables are the general parameters of tiltrotor aircraft. The constraints are the flight performance, structure size and weight efficiency. The objective function is the multi-linear weighted objectives of figure of merit in helicopter mode and the conversion productivity in fixed-wing mode. The optimization results and calculation example compared with the prototype, showed that the ant colony algorithm for this optimization problem is feasible and efficient. Finally, the parameter sensitivity analysis is conducted. The optimal general parameters of tiltrotor aircraft are obtained. The research method in the thesis provides a new way for this type of issue.