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This paper aims to present a methodology of designing a custom propeller for specified needs. The example of propeller design for large unmanned air vehicle (UAV) is considered.

Starting from low fidelity Blade Element (BE) methods, the design is obtained using evolutionary algorithm-driven process. Realistic constraints are used, including minimum thickness required for stiffness, as well as manufacturing ones – including leading and trailing edge limits. Hence, the interactions between propellers in hex-rotor configuration, and their influence on structural integrity of the UAV are investigated. Unsteady Reynolds-Averaged Navier–Stokes (URANS) are used to obtain loading on the propeller blades in hover. Optimization of the propeller by designing a problem-specific airfoil using surrogate modeling-driven optimization process is performed.

The methodology described in the current paper proved to deliver an efficient blade. The optimization approach allowed to further improve the blade efficiency, with power consumption at hover reduced by around 7%.

The methodology can be generalized to any blade design problem. Depending on the requirements and constraints the result will be different.

Current work deals with the relatively new class of design problems, where very specific requirements are put on the propellers. Depending on these requirements, the optimum blade geometry may vary significantly.

The purpose of this paper is to present a method for analysis and optimization of morphing wing. Moreover, a numerical advantage of morphing airfoil wing, typically assessed in simplified two-dimensional analysis is found using higher fidelity methods.

Because of multi-point nature of morphing wing optimization, an approach for optimization by analysis is presented. Starting from naïve parametrization, multi-fidelity aerodynamic data are used to construct response surface model. From the model, many significant information are extracted related to parameters effect on objective; hence, design sensitivity and, ultimately, optimal solution can be found.

The method was tested on benchmark problem, with some easy-to-predict results. All of them were confirmed, along with additional information on morphing trailing edge wings. It was found that wing with morphing trailing edge has around 10 per cent lower drag for the same lift requirement when compared to conventional design.

It is demonstrated that providing a smooth surface on wing gives substantial improvement in multi-purpose aircrafts. Details on how this is achieved are described. The metodology and results presented in current paper can be used in further development of morphing wing.

Most of literature describing morphing airfoil design, optimization or calculations, performs only 2D analysis. Furthermore, the comparison is often based on low-fidelity aerodynamic models. This paper uses 3D, multi-fidelity aerodynamic models. The results confirm that this approach reveals information unavailable with simplified models.

This paper aims to address the issue of designing aerodynamically robust empennage. Aircraft design optimization often narrowed to analysis of cruise conditions does not take into account other flight phases (manoeuvres). These, especially in unmanned air vehicle sector, can be significant part of the whole flight. Empennage is a part of the aircraft, with crucial function for manoeuvres. It is important to consider robustness for highest performance.

Methodology for robust wing design is presented. Surrogate modelling using kriging is used to reduce the optimization cost for high-fidelity aerodynamic calculations. Analysis of varying flight conditions, angle of attack, is made to assess robustness of design for particular mission. Two cases are compared: global optimization of 11 parameters and optimization divided into two consecutive sub-optimizations.

Surrogate modelling proves its usefulness for cutting computational time. Optimum design found by splitting problem into sub-optimizations finds better design at lower computational cost.

It is demonstrated, how surrogate modelling can be used for analysis of robustness, and why it is important to consider it. Intuitive split of wing design into airfoil and planform sub-optimizations brings promising savings in the optimization cost.

Methodology presented in this paper can be used in various optimization problems, especially those involving expensive computations and requiring top quality design.