Peclet Number

Written by Jerry Ratzlaff on . Posted in Dimensionless Numbers

Péclet number, abbreviated as Pe, a dimensionless number, defined as a ratio of heat transport by convection to heat transport by conduction.

Peclet Number fromula

$$\large{ Pe = \frac { v \; \rho \; C \; l_c }{ k } }$$
Symbol English Metric
$$\large{ Pe }$$ = Peclet number $$\large{dimensionless}$$
$$\large{ l_c }$$ = characteristic length $$\large{ft}$$ $$\large{m}$$
$$\large{ \rho }$$  (Greek symbol rho) = density $$\large{\frac{lbm}{ft^3}}$$ $$\large{\frac{kg}{m^3}}$$
$$\large{ Q_{cond} }$$ = heat transfer by conduction $$\large{\frac{Btu}{hr}}$$ $$\large{W}$$
$$\large{ Q_{conv} }$$ = heat transfer by convection $$\large{\frac{Btu}{hr}}$$ $$\large{W}$$
$$\large{ C }$$ = heat capacity $$\large{\frac{Btu}{F}}$$  $$\large{\frac{kJ}{K}}$$
$$\large{ k }$$ = thermal conductivity $$\large{\frac{Btu-ft}{hr-ft^2-F}}$$ $$\large{\frac{W}{m-K}}$$
$$\large{ v }$$ = velocity $$\large{\frac{ft}{sec}}$$ $$\large{\frac{m}{s}}$$