Carmen Vortex Street

Simulate the vortices formed by fluids in blunt bodies of different shapes through interactive demonstration devices, and understand the relevant knowledge and principles of Karman vortex streets in fluid mechanics. The exhibit consists of a booth, three knobs, three modules, a sink, an air outlet device, and a striped light box. Three knobs are fixed on the booth, and three modules are placed in the sink, controlled by corresponding knobs. The air outlet device is located below the sink. The air outlet device is always in the open state to ensure that the water in the sink is moving. The striped lightbox is located above the sink, reflecting the lines on the light into the water. The visitor turns the knob left and right to control the position of the corresponding module in the sink. When the water flow encounters a metal block, it can be seen that the originally non interfering stripes, under the action of water waves, become shaped to bypass the metal block object on both sides. When they meet again, orderly arranged vortices are generated on both sides of the metal block in the opposite direction of rotation. Target audience: Adolescents aged 6-15 years old, display form.

Interaction type: Interactive installation. The unit is designed for unsupervised public use: controls are recessed or shielded, moving parts are enclosed, and the interface is operable by a child of about six with no instruction. Where a screen is used, the language can be switched without changing the hardware, and the content can be replaced on site.

Karman vortex street is an important phenomenon in fluid mechanics, commonly encountered in nature. Under certain conditions, when a steady incoming flow passes around an object, double row vortices with opposite rotation directions and regular arrangement will periodically detach from both sides of the object. After nonlinear action, Karman vortex street is formed. If water flows over bridge piers and wind blows over tall towers, chimneys, power lines, etc., it will form Karman vortex streets. Carmen vortex street has some important applications, so it is necessary to understand its research history and related application situations. The theory of "Karman vortex street" was proposed by the famous scientist von Karman, who found that when water flows through a cylinder, if the speed is fast enough, the direction of water flow is no longer vertically backward, but forms two rows of vortices, and the part between the two rows of vortices is called a vortex street. These two rows of vortices will generate resistance to moving objects. The movement pattern of fish swinging their tail fins will cause the water behind them to form a 'reverse' movement.