Péclet Number

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Peclet number

[pə′klā ‚nəm·bər]
(chemical engineering)
Dimensionless group used to determine the chemical reaction similitude for the scale-up from pilot-plant data to commercial-sized units; incorporates heat capacity, density, fluid velocity, and other pertinent physical parameters.

Péclet Number


a dimensionless number that is a similarity criterion for processes of convective heat exchange; named after the French physicist J. C. Péclet (1793–1857). The Péclet number Pe = vl/a = Cpρvl/γ, where l is the characteristic linear dimension of the surface of heat exchange, v is the fluid velocity relative to the heat exchange surface, a is the thermal diffusivity, Cp is the specific heat at constant pressure, ρ is the density, and λ is the thermal conductivity of the fluid. The number Pe characterizes the relationship between the convective and molecular processes of heat exchange in the flowing fluid. The process of molecular conduction predominates at low Pe values, and the process of heat exchange by convection of the fluid predominates at high Pe values. The relation between the Péclet number, the Reynolds number Re, and the Prandtl number Pr is given by the equation Pe = Re × Pr.

References in periodicals archive ?
However, the relatively small Peclet numbers, <v>x/<D>-x/[lambda], are around one for x > 0.
0] characteristic length (m) p pressure (Pa) Pe Peclet number (-) Pr Prandtl number (-) [r.
The BTCs for vertical flow became steeper as the pore-water velocity, v, fell and the Peclet number increased; Fig.
where A and B are dimensionless coefficients that are functions of the Peclet number [?
Generally, the value of effective radial thermal conductivity is chosen from an effective radial Peclet number.
Since the Peclet number for air and water vapor heat convection and air and water vapor diffusion are both greater than two, the upwind method is used.
where N is the mass-dispersion number (= D/ZV), which is the reciprocal of the column Peclet number, P (= ZV/D), [tau] is the mean travel time or mean residence time of solute, and Z is the distance between the positions of the measurements of input and response concentrations.
If the relaxation of the individual nanotubes is the primary mechanism for the relaxation process, then the rotational Peclet number in a shear flow field of [?
This is feasible since refrigerant flow ensures a high Peclet number, and for higher Peclet numbers, axial conduction can be neglected (MacArthur and Grald 1989).
infinity]], and Pe is the Peclet number that measures the relative strength of convection to diffusion of a particle.