Micro Air Vehicles (MAVs) are catching more and more attentions for their broad application in civilian and military fields. Since the theories on the aerodynamics of low Reynolds number are not maturely presented and the wind-tunnel experiments cost long periods and great expenses. The numerical simulation based on computational fluid dynamics (CFD) is a good method to choose. Through three-dimensional simulation of the wings, the aerodynamic characteristics of the flows around MAVs can be easily obtained. The tip vortices produced around low-Reynolds-number and low-aspect-ratio wings can increase the lift and stall angles. The result of numerical simulation can be used as references of theory analysis and wind-tunnel experiments.

In this paper, a method to synthesis barium titanate nanorods at room temperature and normal pressure by soft chemical is devoloped. Oleic acid is one important raw material in this method which will help to form reaction containers. The nanorods crystallized in the process. Samples were investigate by XRD, TEM and SAD and so on.

A solvothermal method to synthesize barium titanate nanoparticles is employed. In this method many raw materials such as oleic acid, surfactant, sodium hydroxide, alkali barium acetate, alcohol, tetrabutyl titanate are used. When the samples are collected, oleic acid which has mush an account will cover the whole particles. To make the samples cleaner, nitric acid is used to transition oleic acid to elaidic acid which is lighter than water then it will float up to be removed. In the progress to wash off the oleic acid the particles were found to reunite unusually: bigger and cubic particles are formed and the shape seems like single crystal but they are reunitions indeed, we used HTEM to prove this. It means self–assembling might happen through the progress, the spontaneous polarization orient, polarity of molecules will affect this progess.