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Peclet Number is a dimensionless number that deals in the study of transport phenomena in fluid flows. The Peclet Number is defined as the ratio of the rate of advection of a physical quantity by the flow to the rate of diffusion of the same quantity driven by an appropriate gradient. It incorporates heat capacity, density, fluid velocity, and other pertinent physical parameters. The Peclet Number is denoted by the symbol "Pe".

Table of Contents:

**Peclet Number :**

Pe = vρc_{p} D/k

**Velocity :**

v= Pek/ρc_{p}D

**Density :**

ρ = Pek/vc_{p}D

**Heat Capacity :**

c_{p} = Pek/vρD

**Characteristic Length :**

D = Pek/vρc_{p}

**Thermal Conductivity :**

k =vρc_{p}D/Pe

**Where,**

Pe = Peclet Number,

v = Velocity,

ρ = Density,

c_{p} = Heat Capacity,

D = Characteristic Length,

k = Thermal Conductivity

Peclet number is a measure of the relative importance of advection to diffusion. It is named after the French physicist Jean Claude Eugene Peclet. In other words, Peclet Number is termed as a dimensionless group that is used to determine the chemical reaction similitude for the scale-up from pilot-plant data to commercial-sized units.

__Example__:

Calculate the Peclet Number for the given details.

Velocity (v) = 5 m/s

Density (ρ) = 5 kg/m^{3}

Heat Capacity (c_{p}) = 10 J/kg-K

Characteristic Length (D) = 25 m

Thermal Conductivity (k) = 20 W/m-K

__Solution__:

**Apply Formula:**

Pe = vρc_{p} D/k

**Peclet Number (Pe) = 937.5**