Fluid solid coupling problems exist widely in many engineering practices,such as housing and bridge engineer ing,marine engineer ing,windbreak engineering and so on.When the viscous fluid flows through a non-streamlined flexible solid structure,a periodical vortex street is formed behind the solid structure,which induces the fluid force that produces periodic changes,an d makes the solid structure vibrate.The vibration will change the flow field near the solid structure,and then influence the force of the f...