Fluid_Aspect_Course_2_6_1 - nasa/gunns GitHub Wiki
Fluid Aspect Course 2.6.1: Fluid Transport
Compute Flows
Once the solver has solved for the new network node potentials, the links’ computeFlows method is called to compute the flows resulting from the solution.
Example: Conductive flows:
mFlux = A·dp, where:
A is the link admittance that went into the system of equations just solved,
dp is the new delta-pressure across the link from the solution.
ṁ = mFlux * MW, where
MW is the inlet molecular weight.
Some links also change the temperature and mixture of the flow passing through them.
Heat convection is calculated and fluid exit temperature updated.
Reactors & related links add or remove some fluid constituents.
The link’s mInternalFluid PolyFluid object is typically used to hold these new properties.
Some links have multiple internal fluids for handling complex changes.
Fluid Transport
Once the link knows its flow rate and exit fluid properties, it moves the fluid between the nodes.
Flow is removed from the source node at rate ṁ.
Flow is added to the receiving node at rate ṁ:
Links that change the fluid passing through them add their mInternalFluid to the receiving node’s mInflow.
Links that don’t change the fluid add the source node’s mContent to the receiving node’s mInflow.
Mass is conserved: same ṁ added to one node as removed from another.
Some links may add or remove mass due to adsorption/desorption, chemical reaction models, etc.
This is handled in the link’s mInternalFluid or similar
Mass is conserved between the fluid and link’s non-fluid masses associated with the process.