The internal flow field in vortex whistle is simulated by FLUENT. The distributions of internal flow field are obtained. The results show that the internal flow field inside vortex whistle varies with same step and the flow field distributes symmetrically. The flow path is approximation spiral. Along the radial direction The total pressure increases and the resultant velocity increases firstly and then decreases . The resultant velocity ,the tangential velocity and the total pressure inside the cavity decrease with the diameter of the cavities,and the radial velocity and the total pressure in the exit tube increases when the diameter of the cavity.However the axial velocity and the tangential velocity do not vary obviously in the whole vortex whistle.

vortex whistle; swirling flow field; numerical simulation; velocity analysis; pressure analysis