Calculation Of The Unsteady Aerodynamics Based On Two Dimensional Vorticity Field

The intrinsic measurement of aerodynamic force has great potential in force measurement of flapping wing during the research on mechanism of unsteady aerodynamic force. The crux of this method is to relate flow field and the aerodynamic force. The vorticity moment theorem which connects the vorticity field and the aerodynamic force is failed to calculate the aerodynamic force when only the flow field is known in finite domain which is around the body. So, in this thesis, force equations with two different forms to calculate the aerodynamic force in finite domain are formulated basing on vorticity moment theorem. The aerodynamic force is calculated using the formulated equations in the flow field of a flat plate and a circular cylinder under different Re numbers respectively. The results are compared with other methods. Results showed that the formulated equations could actually reflect the magnitude of the force. The results are slightly affected by the size of the control volume. Particularly, the results will decrease a little as the size of the control volume increases outside the boundary layer.