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The unsteady aerodynamic characteristics of a flapping wing are studied. The computational model for the unsteady aerodynamics of flapping wing using strip theory approach has been developed and clarified. The proposed method is used to solve the mechanical flying ornithopter (SlowHawk 2) of flexible wing membrane. In doing so, the model is verified through the computations performed on a mechanical flying Pterosaur replica as well as smaller biological species including the Corvus monedula and Larus canus. The effect of aerodynamic parameters on the performance of these biological flight vehicles is studied. The results are compared with those available in the literature, the overall agreement is excellent. The effect of Reduced frequency is studied defining an optimal design points for sustainable flight conditions (L > W). A manual optimization is performed on the developed code for the SlowHawk 2 in order to get predicted values to be used as an input data for calculating the optimum aerodynamic characteristics of it.

A computational investigation for the 155mm artillery shell was conducted for the purpose of reducing the base drag. Three case studies were conducted to investigate the properties of the flow field around the shell for the flight at different Mach numbers at zero angle of attack. The three cases were: a shell with boattail, a shell with base cavity and a shell with base bleed. Also, combinations of these three cases were investigated. The higher drag reduction was demonstrated when using a combination of the three effects. For this latter case it was possible to realize a drag coefficient reduction of ~60% at subsonic regime and ~20-30% .at transonic and supersonic regimes. Based on the present methodology, a design optimization for minimum drag can be applied on similar flying bodies.

Because the missile is autonomous, its control system must provide adequate flight stability while ensuring sufficient response to track commands. This paper is devoted to investigate the usefulness of the classical and modern control techniques for autopilot design for different evaluation approaches. The present work is concerned with improving the performance of a surface-to-surface controlled aerodynamically guided missile system via both classical PID and predictive autopilots. The design and analysis necessitate somehow accurate system model with different uncertainties via 6-DOF simulation. The governing differential equations of the missile motion are derived with the aerodynamic model of the missile constructed by means of the Missile Datcom software. After obtaining the required aerodynamic stability derivatives using the generated aerodynamic data, the necessary transfer functions are determined based on the equations of the missile motion. Next, the normal acceleration autopilot is designed using the determined transfer functions. The autopilot is designed to realize the command signals generated by the guidance laws which are in the form of normal acceleration components. Using the entire system model, the computer simulations are carried out using the Matlab-Simulink software where the classical and predictive autopilots are compared via time response along the flight path.