The specific calculation of the Reynolds number, and the values where laminar flow occurs, will depend on the geometry of the flow system and flow pattern. If the Reynolds number is very small, much less than 1, then the fluid will exhibit Stokes, or creeping, flow, where the viscous forces of the fluid dominate the inertial forces. As the Reynolds number increases, such as by increasing the flow rate of the fluid, the flow will transition from laminar to turbulent flow at a specific range of Reynolds numbers, the laminar–turbulent transition range depending on small disturbance levels in the fluid or imperfections in the flow system. Laminar flow generally occurs when the fluid is moving slowly or the fluid is very viscous. The Reynolds number is the ratio of the inertial force to the shearing force of the fluid: how fast the fluid is moving relative to how viscous it is, irrespective of the scale of the fluid system.

The dimensionless Reynolds number is an important parameter in the equations that describe whether fully developed flow conditions lead to laminar or turbulent flow. The type of flow occurring in a fluid in a channel is important in fluid-dynamics problems and subsequently affects heat and mass transfer in fluid systems. An object moving through a fluid experiences a drag force in the direction opposite to its motion. Relationship with the Reynolds number Ī sphere in Stokes flow, at very low Reynolds number. In non-scientific terms, laminar flow is smooth, while turbulent flow is rough. Turbulent flow is a less orderly flow regime that is characterized by eddies or small packets of fluid particles, which result in lateral mixing. The threshold velocity is determined by a dimensionless parameter characterizing the flow called the Reynolds number, which also depends on the viscosity and density of the fluid and dimensions of the channel. Laminar flow occurs at lower velocities, below a threshold at which the flow becomes turbulent.

When a fluid is flowing through a closed channel such as a pipe or between two flat plates, either of two types of flow may occur depending on the velocity and viscosity of the fluid: laminar flow or turbulent flow. Laminar flow is a flow regime characterized by high momentum diffusion and low momentum convection. In laminar flow, the motion of the particles of the fluid is very orderly with particles close to a solid surface moving in straight lines parallel to that surface. There are no cross-currents perpendicular to the direction of flow, nor eddies or swirls of fluids. At low velocities, the fluid tends to flow without lateral mixing, and adjacent layers slide past one another like playing cards. In fluid dynamics, laminar flow is characterized by fluid particles following smooth paths in layers, with each layer moving smoothly past the adjacent layers with little or no mixing. This flow profile of a fluid in a pipe shows that the fluid acts in layers that slide over one another.

If the value of Reynolds’s number is more than 4000 then the flow is considered as turbulent flow.The velocity profile associated with laminar flow resembles a deck of cards. If the value of Reynolds’s number is equal to or less than 2000 then the flow is considered as laminar flow. On the other side, if the fluid particles travel in irregular or zig-zag ways then the flow is known as turbulent flow. Note: Laminar flow is also known as stream line flow because the fluid particles travel in a regular, smooth and in straight line path. Reynold’s number is dimensionless number as it is the ratio of Inertial force to viscous force. Hint:To solve this problem,we will apply Reynold's number formula for the laminar flow.

Laminar flow pipe