ConservativeConvectionPDETerm
ConservativeConvectionPDETerm[vars,α]
represents a conservative convection term with conservative convection coefficient and model variables vars.
ConservativeConvectionPDETerm[vars,α,pars]
uses model parameters pars.
Details
- Conservative convection is typically used to model transport due to a bulk movement and should be used when the divergence of convection velocity is nonzero.
- Convection with a conservative convection coefficient is the process of transport of the dependent variable :
- ConservativeConvectionPDETerm returns a differential operators term to be used as a part of partial differential equations:
- ConservativeConvectionPDETerm can be used to model conservative convection equations with dependent variable , independent variables and time variable .
- Stationary model variables vars are vars={u[x1,…,xn],{x1,…,xn}}.
- Time-dependent model variables vars are vars={u[t,x1,…,xn],{x1,…,xn}} or vars={u[t,x1,…,xn],t,{x1,…,xn}}.
- The conservative convection term in context with other PDE terms is given by:
- ConservativeConvectionPDETerm is similar to ConvectionPDETerm but affects the meaning of NeumannValue and has a coefficient that is part of the divergence .
- The conservative convection coefficient has the following form:
-
{α1,…,αn} vector - For a system of PDEs with dependent variables {u1,…,um}, the conservative convection represents:
- The conservative convection term in context systems of PDE terms:
- The conservative convection coefficient is a tensor of rank 3 of the form , where each submatrix is a vector of length that is specified in the same way as for a single dependent variable.
- The conservative convection coefficient can depend on time, space, parameters and the dependent variables.
- The following parameters pars can be given:
-
parameter default symbol "RegionSymmetry" None - A possible choice for the parameter "RegionSymmetry" is "Axisymmetric".
- "Axisymmetric" region symmetry represents a truncated cylindrical coordinate system where the cylindrical coordinates are reduced by removing the angle variable as follows:
-
dimension reduction equation 1D 2D - All quantities that do not explicitly depend on the independent variables given are taken to have zero partial derivative.
Examples
open allclose allBasic Examples (3)
Scope (5)
Define a 1D axisymmetric time-independent conservative convection term:
Apply Activate to the term:
Verify that the axisymmetric case is a consequence of using a truncated cylindrical coordinate system using the operators that compose the conservative convection term:
Define a 2D stationary conservative convection term:
Define a 2D axisymmetric time-independent conservative convection term:
Apply Activate to the term:
Verify that the axisymmetric case is a consequence of using a truncated cylindrical coordinate system using the operators that compose the conservative convection term:
Define a conservative convection term with multiple dependent variables:
Define an axisymmetric conservative convection term with multiple dependent variables:
Possible Issues (2)
A conservative convection term with a 0-flow velocity field evaluates to 0:
A symbolic conservative convection coefficient is interpreted as a vector convection coefficient:
A subsequent substitution must account for that:
An alternative is to specify the symbolic convection coefficient as a vector:
Text
Wolfram Research (2020), ConservativeConvectionPDETerm, Wolfram Language function, https://reference.wolfram.com/language/ref/ConservativeConvectionPDETerm.html.
CMS
Wolfram Language. 2020. "ConservativeConvectionPDETerm." Wolfram Language & System Documentation Center. Wolfram Research. https://reference.wolfram.com/language/ref/ConservativeConvectionPDETerm.html.
APA
Wolfram Language. (2020). ConservativeConvectionPDETerm. Wolfram Language & System Documentation Center. Retrieved from https://reference.wolfram.com/language/ref/ConservativeConvectionPDETerm.html