FLOWS in infinitesimal parallel layers with no disruption between them as SHOWN in Fig. (a)In laminar flows, fluid layers slide in parallel, with no EDDIES, swirls, or currents normal to the flow itself.This type of flow is also REFERRED to as streamline flow because it is characterized by non-crossing streamlines.Turbulent flow: In a closed pipe, when fluid layers slide is not in parallel to the other layer, then the flow is called turbulent flow. Fig. (b)a) b) Reynolds number:The Reynolds number is an IMPORTANT dimensionless quantity in fluid mechanics used to predict flow patterns in different fluid flow situations.Reynolds number is below 2000, laminar flow happens.Reynolds number is above approximately 4000, the flow will be turbulent.In between these two limits, the flow is termed as “transition flow”.