moment

EQ = moment{0|1|2|3} {Galerkin_wt} {MOM0|MOM1|MOM2|MOM3} {Interpol_fnc} <floatlist>

Description / Usage

This card provides information for solving a differential equation for one component of a population balance equation

All four moments are expected to be enabled at the same time

moment0 | moment1 | moment2 | moment3

Name of the equation to be solved, where the and 3 components correspond to one of the principal coordinate directions, e.g. X, Y and Z for Cartesian geometry.

{Galerkin_wt}

Two- or four-character value that defines the

type of weighting function for this equation, where:

• Q1-Linear

• Q2-Quadratic

MOM0 | MOM1 | MOM2 | MOM3

Name of the variable associated with the moment equation

{Interpol_fnc}

Two- or four-character value that defines the

interpolation function used

• Q1-Linear Continuous

• Q2-Quadratic Continuous

<float1>

Multiplier on mass matrix term ( d ⁄dt ).

<float2>

Multiplier on advective term.

<float4>

Multiplier on diffusion term.

<float5>

Multiplier on source term.

<float6>

Multiplier on divergence term

Note: These multipliers are intended to provide a means of activating or deactivating terms of an equation, and hence should be set to zero or one. If a multiplier is zero, the section of code that evaluates the corresponding term will be skipped.

Examples

EQ = moment0 Q1 MOM0 Q1 1. 1. 1e-6  1. 1.
EQ = moment1 Q1 MOM1 Q1 1. 1. 1e-6  1. 1.
EQ = moment2 Q1 MOM2 Q1 1. 1. 1e-6  1. 1.
EQ = moment3 Q1 MOM3 Q1 1. 1. 1e-6  1. 1.

Technical Discussion

No Discussion.

References

Ortiz, Weston, Lisa Mondy, Christine Roberts, and Rekha Rao. “Population balance modeling of polyurethane foam formation with pressure‐dependent growth kernel.” AIChE Journal 68, no. 3 (2022): e17529.