Determination of runway orientation is a prime factor affecting the layout of airport facilities. This paper presents a new computer model called TORO (Tool for Optimum Runway Orientation) which is developed with an approach different from that of the Federal Aviation Administration's (FAA) wind rose method. All models previously developed are based on this traditional method. In the new model, each wind observation is evaluated individually in the computations without grouping them. Thus, the errors arising from the partial coverage problem and the FAA's assumption related to distribution of winds in each cell of wind rose are eliminated. The new model is written in CSharp (C#) programming language and the wind data tables are prepared in Access format. The accuracy, reliability and flexibility of the model are tested with three numerical examples. The results demonstrate that the TORO model may be a valuable tool for airport planners and designers.

In this paper, a new optimisation method incorporating lamination parameters and a guide-based blending model is proposed. Lamination parameters for a guide laminate and ply number of each panel are employed as design variables for optimisation with a parallel real-coded genetic algorithm incorporating structure behaviour and manufacturing constraints. During the optimisation process, with a form of least squares fitting adopted, another genetic algorithm is used to obtain the guide stacking sequence of the guide laminate from the guide lamination parameters, and then the laminate configurations of each panel are obtained from the guide stacking sequence and number of plies for each panel. The proposed framework is demonstrated via design of an 18-panel horseshoe configuration, where each panel is optimised individually with a buckling constraint. Numerical results indicate that the present algorithm is capable of obtaining fully blended designs.

A multi-objective optimisation process is used to design winglets for a high-performance sailplane. The primary optimisation objective is to maximise the average cross-country speed over a range of thermal strengths. Additional contributions to the cost functions are the limitation of the total drag during high-speed cruise and the additional root bending moment due to the winglet. Rather than being a pure design study, the purpose of the herein presented study is to demonstrate that a multi-objective optimisation approach is a suitable and efficient alternative to the more traditional, experienced-based design approach. The flight performance of the winglet designs are evaluated using a higher-order potential flow method. Results of the optimisation are hand-selected for further analysis. They are compared to a traditionally designed winglet for the same aircraft, designed with similar objectives in mind. The chosen final designs provide an increase in average cross-country speed of 1.5% at lower thermal strengths and 0.4% at higher thermal strengths when compared to the traditional design. When approximating the effects of trim drag due to wing loading and static margin, these performance gains fall to 0.6% and 0.1% respectively, more closely matching the performance of the traditionally designed winglet. The final designs, along with the traditional design, provide performance benefits across all airspeeds of the flight envelope of the base aircraft without winglets.

The service life of aircraft structure includes the fatigue life and calendar life. The Aircraft Structural Life Envelop (ASLE) is a safe and reliable life scope of aircraft structures in service. The specific steps to establish the ASLE are developed, and a residual life prediction method for aircraft structure under service environments is established by combining the ASLE with the Miner theory. Furthermore, a service life extension method of aircraft structure is proposed based on a scope extension of the ASLE, including methods based on reliability analysis and structural repair. Finally, an application example of the ASLE is presented.

This paper compares two periodic control methods, the optimal H 2 and the periodic static output feedback (POF), to reduce the helicopter rotor vibrations. Actively twisted blades with Macro-Fibre Composite (MFC) piezoelectric actuators are used. The design model is based on a simplified aerodynamic model and on a multi-body model of the Bo 105 isolated rotor with the original blades replaced by actively twisted ones. The performance of the two controllers in alleviating hub loads is verified with improved simulations based on a free-wake model.

Two methods have been compared for the determination of the inertial properties of a small, fixed-wing un-manned aerial vehicle. The first method uses the standard single degree of freedom pendulum method and the second method implements a novel, potentially easier, 3 degrees of freedom pendulum method, which yields the entire inertia tensor from a single swing test. Both methods are using system identification of the pendulum motion to estimate the inertial properties. Substantial corrections (up to 25%) have to be applied to the experimental results. These corrections are caused by the acceleration of the pendulum being immersed in the surrounding air, also called the added mass effect. It has been found that the methods presented in literature to determine the corrections for full-scale aircraft do not give the correct results for the small-scale un-manned aerial vehicle under consideration. The only feasible, cost-effective method to generate these corrections utilise swing tests with a geometrically similar object of known inertial properties. It has also been found that the corrections are unique with respect to the experimental methods. Several benchmarking methods, including the innovative use of static and dynamic wind-tunnel test data, give high confidence in the results.

This work presents the capabilities of a novel L-shaped trailing-edge Gurney flap as a device for vibration reduction. The primary effect of this L-tab is represented by a modification of the reference aerofoil mean line shape through by two counter-rotating vortical structures created at the trailing edge. The comparison of the aerodynamic loads generated by the novel L-tab Gurney flap and a classical trailing-edge flap allows to estimate the ranges of reduced frequency where the L-tab is expected to perform better than a trailing edge flap and vice versa. Linear aerostructural models for a typical section representative of a helicopter blade equipped with a partial-span L-tab or a trailing-edge flap are built, and a higher harmonic control algorithm is applied. Performance are compared between the two devices to reduce separately the N/rev harmonics of the blade root rotating frame vertical force, flapping and feathering moments. The attainment of similar results with classical trailing-edge device is a further confirmation of the potential feasibility of this novel L-tab as an effective alternative means for vibration reduction on rotor blades.