particle flow 模塊
You can include particles in an OLGA model by using the PARTICLEFLOW key under the OPTIONS keyword. Two models are available: SIMPLE and ADVANCED, as described in Model description.
Particles can be entered into pipelines through sources or boundary nodes, and corresponding initial conditions can be set in INITIALCONDITIONS, as well as for internal nodes, phase split nodes and separators.
Particles can be defined both for compositional and non-compositional simulations. The SIMPLE model can be used in both cases, while the ADVANCED model can be used only in non-compositional cases.
The particle flow functionality can be used with drilling fluids by setting DRILLING = ON under the OPTIONS keyword to simulate drilling scenarios. For more details see Drilling fluid.
Properties
The density, diameter and heat capacity of the particles can be specified through the PARTICLES keyword under Library. Only one type of particle can be specified for one simulation. If this keyword is not specified, the default values are used.
Additionally, it is possible to adjust the properties of the particle bed for the ADVANCED model. The available parameters are the angle of repose and the porosity of the bed. The corresponding input keys can be defined using the PARTICLEOPTIONS keyword. Default values are used if this keyword is not defined.
Boundary conditions
Particle flow can be specified by the PARTICLEFRACTION key in SOURCE or NODE. The value to enter here is the mass of particles divided by the mass of the total mixture.
Initial conditions
An initial distribution of particles can be specified using the PARTICLEFRACTION key under the INITIALCONDITIONS keyword.
Additionally, the initial mass fraction of particles can be given for internal nodes, separators and phase split nodes using the PARTICLEFRACTION key in the corresponding keywords. An exception to this rule is that the value is specified through the CUTTING component in a FEED when setting DRILLING=ON and COMPOSITIONAL=OFF under OPTIONS, see Drilling fluid). This is to maintain backward compatibility.
Output variables
A number of output variables related to the particles are available for TREND and PROFILE plots under the variable group ParticleFlow. A comprehensive list can be found under Particle flow Output Variables.
Extensions
Particle flow models can be added using extensions. These models are available in the key PARTICLEMODEL, under PARTICLEOPTIONS. To use these, the PARTICLEFLOW=ADVANCED must be selected. The key BEDPOROSITY will be available as a tuning parameter for the extension model. However, the model may not take the parameter into account. Refer to the documentation of the extension for more details.
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