抄録
Wakes and vortex streets such as those occurring behind towed or self-propelled bodies are generated by moving forces in a viscous fluid at moderate values of the Reynolds number, Re〜10^2. In our experiments the forcing is provided by electromagnetic method and allows us to create a "virtual" body without introducing any solid objects into the fluid. Similarly, in our numerical simulations the force on the fluid is applied within a circular area of finite size. Characteristics of stable and unstable wakes in particular the shedding frequency are measured in the space of control parameters, namely the magnitude of forcing and the speed of translational motion of the forcing. The problem for the single force considered here has an extra degree of freedom compared to the classical problem of the flow around a cylinder and exhibit a wider array of different regimes.
