the path of the tube of flow. Thus a tube of flow dictates the path of travel much as a pipe of the same shape would.
Fluids can be classified by several characteristics. If the velocity of the flow is constant at each point, the fluid has a steady flow; otherwise the flow is non steady. If small parts of the fluid rotate around a point, the fluid has rotational flow. Most cases in this material are examples of irrotational flow. Compressible flow implies the density of the material changes with the flow, whereas incompressible flow describes density that remains fairly constant throughout the flow. The viscosity h of a fluid describes the tendency of the layers to stick together. The layers of a viscous fluid resist separation, while those of a non viscous fluid do not. Viscosity is measured in units of . The CGS unit has dimensions of
