EQ = lubp_2 {Galerkin_wt} LUBP {Interpol_fnc} <floatlist>

Description / Usage#

This card provides information for solving a second-layer Reynold’s lubrication equation for confined flow. The second layer is solved on an adjacent shell as lubp equation but shares the same nodes. Please consult tutorials for proper usuage. This equation can be used to model transport between alternating stacks of porous materials. Definitions of the input parameters are defined below. The Galerkin weight and the interpolation function must be set the same for the code to work properly. Counterparts to this equation for lubrication flow of capillary films (film-equations) are shell_filmp and shell_filmh equations.


Name of equation to be solved.


Two-or four-character value that defines the type of weighting function for this equation, where:

  • Q1–Linear

  • Q2–Quadratic (not recommended at this time)


Name of the variable associated with this equation.


Two-or four-character value that defines the interpolation function for the variable LUBP_2 where:

  • Q1–Linear

  • Q2–Quadratic (not recommended at this time)


Multiplier for the mass matrix term (not used yet as of 3/4/2010).


Multiplier for the diffusion term.


Multiplier for the source term.


Following is a sample card:

EQ = lubp_2 Q1 LUBP_2 Q1 1. 1. 1.

This applies the confined flow lubrication equation with all terms activated.

Technical Discussion#

The equation solved is as follows:

  • The first term multiplier, activating the mass (time-derivative) term is not currently activated as the gap-height is user-prescribed.

  • The second term multiplier affects the third and fourth terms (grad_p and surface tension terms).

The third term multiplier activates the Couette flow terms.