Practical significance of reynolds number?

Answer 1

The Reynolds number is a measure of the relative magnitude of inertia forces to viscous forces in a flow.
It allows us to compare different flows in a consistent way. Two fluids having different viscosities, flowing past two different sized but geometrically similar bodies, and at different speeds will have the same flow patterns and intensive forces if they have te same Reynolds number. Among other things, this allows us to use scaled down models to study the flow past objects before actually building them,or flows in bays, rivers, etc.

Answer 2

A quick way of determining if flow in a system is laminar or turbulent. Heat exchanges prefer turbulent flow so by varying one term (flow rate, diameter of pipe etc) the magic 1500 can be gained.

For other systems laminar flow is needed. Viscosity systems can also be checked.

I used to sell pumps, meters and compressors to the petrochemical industry. Plugging in diameter of pipe, viscosity of product, required flow rate into a Reynolds number function graph allowed for speedy determination of the systems limitation and needs.

Answer 3

Reynolds number is resultant of few variables which can be measured. namely Diameter, Velocity, density & kinematic viscosity of a fluid. This condition apply for fluids in confined boundry conditions, ie: in pipes etcx.

Reynold number (Nre) = D.V. (Rho) / mu

the ratio indicates the state of fliud flow :

for example Nre= 0- 3000 , indicates smooth, corvet flow
3000 -- 10,000 shows non turbulent or controlled flow. also in the lower values of this value is laminar flow ( upto 7000 Nre)

above 10,000 or more, it is turbulent or dynamic flow

Now to use its impotantce in application:

1. it helps in design of pipes, bends, process vessels
2. It is helpful energy calculations
3. It can determine the mixing process of many fluids in one vessel or pipe
4. It is used in design of auronautical structures
5. Your house hold Laudandry machine is also designed using this factor
6. many more theoretical calculations for research.

Answer 4

They determine if you are in laminar flow or turbulent flow.

Laminar flow is more efficient.