Explicit solver for droplets which may interact and collect as water films along boundaries
For using the DROPLETPHASE solver, choose the kind of problem as
The value H:MIN_FACTOR is optional and can be set between 0 and 1. It allows to adaptively reduce the smoothing length H, if too many points collect at the same place. This can prevent an extreme increase in the number of neighbor points, which contributes to a significantly improved performance in such situations. The default value is 1, which means that H is not changed. If a value smaller than 1 is given, the smoothing length can be reduced no further than to the value given in the input file times the specified factor.
The value of CORNER_TREATMENT_VERSION:N is also optional and addresses only those points collecting as thin layer on a rigid surface (LiquidLayer). The value of N can be chosen between 0 and 5, see SlidingThroughCorners. If not set it defaults to 4.
Each point represents a volume of material. We assume droplet form, the volume is given with respect to the given diameter %ind_d30%. Since points in the DROPLETPHASE represent discrete physical entities rather than numerical discretization points, they are not subject to the same point organization as, for example, the LIQUID phase.
The time step criteria for DROPLETPHASE chambers are described in TimeStepCriteria
There are several types of droplet dynamics which can be modeled within the DROPLETPHASE solver:
This movement is governed by applying gravity forces or the Darcy ansatz as dynamic of freely flying droplets. See FreeFlight
On slip walls, a liquid layer ansatz can be employed, where droplets collect and form a thin film. See LiquidLayer
DropletCollisions (droplet-droplet and droplet-wall) are modeled by integrating the interaction forces (Discrete Element Model, soft shell approach). See DropletCollisions
For walls, a definition can be given, when points shall be locked there. This can be used for modelling clustering (similar to a hard shell approach) . See DROPLETPHASE_LockedPoints_Collision
List of members: | |
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TimeStepCriteria | DROPLETPHASE - Time step criteria |
FreeFlight | DROPLETPHASE - Modeling of free flight droplets |
LiquidLayer | DROPLETPHASE - Modeling of liquid layers |
DropletCollisions | DROPLETPHASE - Modeling of collisions between droplets |
Parcels | DROPLETPHASE - Auto clustering particles to speed up simulations |
This item is referenced in: | |
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FAQ | overview of frequently asked questions and hints for solution |
CollidingDropletsInCone | Colliding droplets in cone geometry |
ChannelWithFilter | Coupled simulation of droplets and air in a channel with filter |
WaterSand | A jet of water and sand hits a plate |
LiquidLayerExample | Droplets forming a liquid layer on a plate |
%ind_Vi% | volume represented by a point, unit=m^3 |
%ind_grad_hwf(1)% | if droplets collect on a boundary: gradient of height of accumulated water film, x-component [1] |
%ind_grad_hwf(2)% | if droplets collect on a boundary: gradient of height of accumulated water film, y-component [1] |
%ind_grad_hwf(3)% | if droplets collect on a boundary: gradient of height of accumulated water film, z-component [1] |
%ind_hwf% | if droplets collect on a boundary: height of accumulated water film [m] |
%ind_lap_hwf% | if droplets collect on a boundary: Laplacian of the height in tangential direction (i.e. curvature of the accumulated water film) [1/m] |
%ind_MUE_relax% | DROPLETPHASE: locked points: slope of the forces (viscous, same sense as ind_ETA) before reaching the Coulomb friction force given by ind_MUE |
%ind_mult% | Multiplicity: Number of particles represented by this parcel / cluster. |
%ind_tContact% | DROPLETPHASE: contains the contact time of prospective collisions |
dist_parceling | (experimental / Under development) Maximum relative distance to initiate parceling |
dist_parceling_FreeFlight | (experimental / Under development) Maximum relative distance to initiate parceling |
DROPLETPHASE_nbTSforParceling | Number of time steps after which parceling will be done |
IPC_ReadMultipleFramesDuringRuntime | (experimental) switch to enable read in of multiple frames for ReadInPointCloud |
ORGANIZE_DistanceToBoundary_Version | define version number for distance-to-boundary computations |
dist_parceling | (experimental / Under development) Maximum relative distance to initiate parceling (UCVO) |
dist_parceling_FreeFlight | (experimental / Under development) Maximum relative distance to initiate parceling in free flight (UCVO) |
DROPLETPHASE_MaxEquivalentParcelDiameter | Limiting maximum equivalent parcel diameter for parceling in DROPLETPHASE (UCVO) |
DROPLETPHASE_MaxRelativeParcelVelocity | Limiting maximum relative parcel velocity for parceling in DROPLETPHASE (UCVO) |
DROPLETPHASE_MinNeighboursForParceling | Limiting number of neigbors to trigger clustering in DROPLETPHASE (UCVO) |
DROPLETPHASE_ParcelingDiameterClasses | defines classes for diameters for parceling. And parceling is only done whent two parcels are in the same class. |
COEFF_dt_coll | time step criterion from interaction model (DROPLETPHASE only) (UCV) |
COEFF_dt_d30 | time step criterion depending on %ind_d30% (DROPLETPHASE only) (UCV) |
COMP_DropletphaseSubcycles | switch for DROPLETPHASE subcycling (UCV) |
COMP_DropletphaseWithDisturbance | disturbance for DROPLETPHASE (UCV) |
dist_parceling | (experimental / Under development) Maximum relative distance to initiate parceling (UCVO) |
dist_parceling_FreeFlight | (experimental / Under development) Maximum relative distance to initiate parceling in free flight (UCVO) |
DP_UseOnlyRepulsiveContactForce | switch regarding attractive forces in spring-damper model (UCV) |
IDENT | (required) how to handle the geometry part during point cloud organization |
%IDENT_none% | inactive BE (IDENT) |
%IDENT_void% | invisible precision measurement BE (IDENT) |
%IDENT_BlindAndEmpty% | invisible flux measurement BE (IDENT) |
%IDENT_wall% | non-moving wall points BE (IDENT) |
%IDENT_slip% | movable wall points BE (IDENT) |
%IDENT_inflow% | inflow BE (IDENT) |
%IDENT_outflow% | outflow BE (IDENT) |
%IDENT_ThinFilm% | wall layer points (IDENT) |
%TOUCH_reflection% | points reflected at boundary |
%BND_slip% | Slip liquid layers for Dropletphase |
%BND_COLLISION% | velocity boundary condition to represent collisions |
DROPLETPHASE_LockedPoints_Collision | Mixed definition of repulsion / locking of DROPLETPHASE points at walls or clusters |
DROPLETPHASE_LockedPoints_Detachment | releases DROPLETPHASE points from the %IDENT_locked% state |
DROPLETPHASE_LockedPoints_Modification | modify function values of DROPLETPHASE points in the %IDENT_locked% state |
COMP_DropletphaseParcels | (experimental / Under development) cluster particles together in DROPLETPHASE |
BasedOnVolumeFlux | generate a sequence of spherical droplets based on user defined volume flux |
nbsum() | sum over points in neighbor list |
opDrPh() | various operators (diffusion, moment) on the DROPLETPHASE |
%INTEGRATION_INT% | volume integration of a functional with respect to a given material |
%INTEGRATION_INT_TIME% | volume and time integration of a functional with respect to a given material |
%INTEGRATION_FLUX% | flux integration of a functional by counting the MESHFREE points that slip over a given control surface |
%INTEGRATION_FLUX_IN% | flux integration of a functional by counting the newly injected MESHFREE points |
%SUMMATION_INT% | summation of given function values based on all MESHFREE points with respect to given material flags |
%AVERAGE_INT% | average of a functional based on all MESHFREE points with respect to given material flags |
Solvers | Select the solver base on a physical model |
DarcyConstant | coupling parameter for porous media [kg/(s*m^3)] |
%MED_LIQUID_FILM% | viscosity definition in liquid films [Pa*s] |
ParticleInteraction | defines the dynamics of particle-particle interaction within the DROPLETPHASE as material property |
ReadInPointCloud | read in an already existing point cloud from file |
EnSight | read in already existing point cloud from EnSight format |
%INTEGRATION_FLUX_DROPLETPHASE% | flux integration of a functional by counting the DROPLETPHASE points that slip over a given control surface |
%MASSFLOW_DROPLETPHASE% | mass flux integration of a functional by counting the DROPLETPHASE points that are injected at all inflow surfaces |
Beta | Latest release notes for the MESHFREE beta executables |
All | Complete release notes for the MESHFREE beta executables |
Stable | Release notes for the MESHFREE stable executables |
NamesOfStopWatches | currently implemented stop watches |
Numerics | PDE to be solved and the meshfree algorithms to solve the PDE |
DROPLETPHASE | Explicit solver for droplets which may interact and collect as water films along boundaries |
TimeStepCriteria | DROPLETPHASE - Time step criteria |
FreeFlight | DROPLETPHASE - Modeling of free flight droplets |
LiquidLayer | DROPLETPHASE - Modeling of liquid layers |
DropletCollisions | DROPLETPHASE - Modeling of collisions between droplets |
Parcels | DROPLETPHASE - Auto clustering particles to speed up simulations |