To processes may be considered completely similar if they take place in a similar geometrical space and if some the dimensionless number necessary to describe them have the same numerical value.

To processes may be considered completely similar if they take place in a different geometrical space and if all the dimensionless number necessary to describe them have the same numerical value.

To processes may be considered partially similar if they take place in a different geometrical space and if all the dimensionless number necessary to describe them have the same numerical value.

To processes may be considered completely similar if they take place in a similar geometrical space and if all the dimensionless number necessary to describe them have the same numerical value.

$\mu=\frac{l_A}{l_B}$

$\mu=\frac{l_T}{l_M}$

$\mu=\frac{l_M}{l_T}$

$\mu=\frac{l_L}{l_M}$

$\left\{h,d;\rho,v,k,\rho Cp;v\right\}$

$\left\{h;d;\rho,v,k,\rho Cp,v\right\}$

$\left\{h;d;\rho,v,k,\rho Cp;v\right\}$

$\left\{h,d;\rho,v,k,\rho Cp,v\right\}$

3

4

5

$ML^1$

$ML^2$

$ML^3$

$ML^{-3}$

The reduction of the rank of the pi-set

The reduction of the pi-set itself (a row and a column to be of zero values)

The reduction of the pi-set itself (a row or a column to be of zero values)

Nusselt number (Nu)

Reynolds number (Re)

Fourier number (Fo)

Prandtl number (Pr)