# MassSymmetryValue

MassSymmetryValue[pred,vars,pars]

represents a mass symmetry boundary condition for PDEs with predicate pred indicating where it applies, with model variables vars and global parameters pars.

MassSymmetryValue[pred,vars,pars,lkey]

represents a mass symmetry boundary condition with local parameters specified in pars[lkey].

# Details   • MassSymmetryValue specifies a boundary condition for MassTransportPDEComponent and is used as part of the modeling equation:
• • MassSymmetryValue is typically used to model a boundary with mirror symmetry along an axis.
• • MassSymmetryValue models a boundary with mirror symmetry with dependent variable , independent variables and time variable .
• Stationary variables vars are vars={c[x1,,xn],{x1,,xn}}.
• Time-dependent variables vars are vars={c[t,x1,,xn],t,{x1,,xn}}.
• The non-conservative-time dependent mass transport model MassTransportPDEComponent is based on a convection-diffusion model with mass diffusivity , mass convection velocity vector , mass reaction rate and mass source term :
• • The conservative time-dependent mass transport model MassTransportPDEComponent is based on a conservative convection-diffusion model given by:
• • The normal flow velocity on the symmetry boundary will remain at zero at all times.
• Both in the conservative and non-conservative forms, MassSymmetryValue with boundary unit normal models:
• • Model parameters pars as specified for MassTransportPDEComponent.
• The following additional model parameters pars can be given:
•  parameter default symbol "ModelForm" "NonConservative" • MassSymmetryValue is effectively the same as MassFluxValue with a heat flux of 0.
• The boundary predicate pred can be specified as in NeumannValue.
• If the MassSymmetryValue depends on parameters that are specified in the association pars as ,keypi,pivi,], the parameters are replaced with .

# Examples

## Basic Examples(3)

Set up a mass symmetry boundary condition:

Set up a system of mass symmetry boundary conditions:

Symmetry boundaries can be used to reduce the size of the geometry of the model. Set up a mass transport equation:

Set up and visualize a region:

Solve and visualize the equation:

Set up a region about the symmetry axis at :

Solve and visualize the equation with a symmetry boundary at :