Under such conditions, a considerable increase in stall margin improvement and stall flow m.

Further, the air-separator improves the low flow rate range performance and increase stall margin of the axial flow fan.

Analysis shows that controlled-vortex aerodynamics can make reaction more uniform,but it is limited to some extent because of larger leaving loss when it is used to last stage of large steam turbine.

The limit velocity formula adapted for battle damage simulation was chosen, and the method of calculating the terminal velocity was proposed.

The principles implied in the process of EFP(explosively formed projectile) impacting the plate covered explosive and the ceramic composite armor have provided the evidence for calculating the residual velocity of EFP(explosive formed projectile) impacting a new integrated armor,and a calculation model has been induced.

Then we can formulate some empirical formulas about ballistics limit and residual velocity,which are based on a large number of computation data.

This paper analyzes the impact damage forecast for the airplane structure from the following four aspects: ballistic limit, residual velocity, residual mass, forecast of damage size in structure penetrated or not penetrated, simultaneously discusses the development tendency of damage forecast and finally points out the main direction and means in the future damage forecast research.

According to the ballistic experimental results and the theoretical analysis,the linear relation between ballistic limit vBL and area density ρad was confirmed;the versatile experiment relation between vr and ρad was found based on that relative parameters in the experiential relation of residual velocity were expressed by the function of ρad.