Below we show Reynolds number calculation example with Excel.

## 1. Functional analysis for Reynolds number calculation

Reynolds number is a function of flow regime of fluid, which could be a reference to define a turbulent flow or laminar flow. It is an indicator that the heat exchanger or a pipe is in turbulent or laminar flow.You check **Wikipedia** for it’s difinition.

## 2. How to calculate the Reynolds number with excel

firstly we need to know the density, hydraulic diameter, velocity,dynamic viscosity of the fluid. There are two ways to obtain the data above, one way is to look the reference table ,the other way is use REFPROP.

For example Reynolds number in a pipe , we use REFPROP to calculate coefficient of thermal conductivity of water under 10℃&0.1Mpa pressure atmosphere, the result come out 0.57877w/mk.

An excel is prepared to calculate Reynolds number in a pipe, you just need to fill in the column.

Above EXCEL calculation show the Reynolds number for water under 10℃ &0.1Mpa pressure atmosphere, the result is 9569 with specific diameter and velocity. Then we change only the hydraulic diameter from 0.0025 to 0.005m, see what happen,Reynolds number in a pipe is changed.

EXCEL is useful for Reynolds number calculation. Send me email to david.teng.fiter@gmail.com, I will share you the excel.