1. Karman vortex and phenomenon

To illustrate the selection of Carmen Vortex, we have to consider the viscous fluid flow around a cylinder flows. When the fluid at a low speed, fluid former resident rate to zero, to flow along the right and left cylinder flows, in the first half of the cylinder Gradually increasing the speed, pressure drop, the rate of decline in the second half, the pressure increased, the rate is zero after the news. At that moment, the ideal fluid flow and the same EC-cylinder, without a vortex, as in Figure 3-7 a Show.

With the flow rate of increase in the latter part of the cylinder pressure gradient increases, caused fluid boundary layer of separation, as shown in Figure 3-7 b. When the flow of Reynolds number Re to increase, reaching around 40 pm , Since the latter part of a cylinder in the fluid surface-Mission greater block, on the surface of the separation points at S have one pair of rotating in the opposite symmetrical vortex. As shown in Figure 3-7 c.

Must stay in the hospital within a few Re, the stability of the vortex of Carmen and vortex shedding frequency and fluid flow in direct proportion.

Figure 3-7 cylinder around the vortex generated diagram