What is irrotational vortex?

An irrotational vortex is a flow pattern in which the fluid motion possesses no vorticity. This means that there is no rotation associated with the flow. In other words, each particle of the fluid moves in a circular path around the center of the vortex. The motion is purely tangential and the speed of the fluid decreases as the distance from the center increases. An irrotational vortex is also known as a potential vortex because the fluid motion is described by a scalar potential function. Potential vortex flows are common in fluid dynamics and can be found in many natural phenomena, such as the circulation of air around a tornado or the flow of water around a draining sink. They are also studied in engineering applications, such as the design of wing profiles in aerodynamics and wind turbine blades in renewable energy.