Public Member Functions | List of all members
LehrMilliesMewesCoalescence Class Reference

Model of Lehr et al. (2002). The coalescence rate is calculated by. More...

Inheritance diagram for LehrMilliesMewesCoalescence:
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Public Member Functions

 TypeName ("LehrMilliesMewes")
 Runtime type information. More...
 
 LehrMilliesMewesCoalescence (const populationBalanceModel &popBal, const dictionary &dict)
 
virtual ~LehrMilliesMewesCoalescence ()
 Destructor. More...
 
virtual void addToCoalescenceRate (volScalarField::Internal &coalescenceRate, const label i, const label j)
 Add to coalescenceRate. More...
 
- Public Member Functions inherited from coalescenceModel
 TypeName ("coalescenceModel")
 Runtime type information. More...
 
 declareRunTimeSelectionTable (autoPtr, coalescenceModel, dictionary,(const populationBalanceModel &popBal, const dictionary &dict),(popBal, dict))
 
 coalescenceModel (const populationBalanceModel &popBal, const dictionary &dict)
 
autoPtr< coalescenceModel > clone () const
 
virtual ~coalescenceModel ()
 Destructor. More...
 
virtual void precompute ()
 Precompute diameter independent expressions. More...
 

Additional Inherited Members

- Static Public Member Functions inherited from coalescenceModel
static autoPtr< coalescenceModel > New (const word &type, const populationBalanceModel &popBal, const dictionary &dict)
 
- Protected Attributes inherited from coalescenceModel
const populationBalanceModel & popBal_
 Reference to the populationBalanceModel. More...
 

Detailed Description

Model of Lehr et al. (2002). The coalescence rate is calculated by.

\[ \frac{\pi}{4} (d_i + d_j)^2 \mathrm{min}(u^{\prime}, u_{\mathrm{crit}}) \mathrm{exp} \left[ - \left(\frac{\alpha_{\mathrm{max}}^{1/3}}{\alpha^{1/3}} - 1\right)^2 \right]\,, \]

where

\[ u^{\prime} = \mathrm{max} \left( \sqrt{2} \epsilon_c^{1/3} \sqrt{d_i^{2/3} + d_j^{2/3}}, |\vec{u}_i - \vec{u}_j| \right) \]

is the characteristic velocity for coalescence. Note that a velocity difference between bubble i and j is only present if the corresponding size groups are assigned to different velocity groups.

$ d_i $ = Diameter of bubble i [m]
$ d_j $ = Diameter of bubble j [m]
$ \epsilon_c $ = Turbulent dissipation rate of continuous phase [m^2/s^3]
$ \alpha $ = Total void fraction of the bubbles [-]
$ \alpha_{max} $ = Maximum packing density of the bubbles [-]
$ u_{crit} $ = Critical velocity for coalescence [m/s]
$ \vec{u}_i $ = Velocity vector of bubble i [m/s]
$ \vec{u}_j $ = Velocity vector of bubble j [m/s]

Reference: 

        Lehr, F., Millies, M., & Mewes, D. (2002).
        Bubble‐size distributions and flow fields in bubble columns.
        AIChE Journal, 48(11), 2426-2443.
Usage
Property Description Required Default value
uCrit Crit. coalescence velocity no 0.08
alphaMax Maximum packing density no 0.6
Source files

Definition at line 148 of file LehrMilliesMewesCoalescence.H.

Constructor & Destructor Documentation

◆ LehrMilliesMewesCoalescence()

LehrMilliesMewesCoalescence ( const populationBalanceModel &  popBal,
const dictionary &  dict 
)

Definition at line 53 of file LehrMilliesMewesCoalescence.C.

◆ ~LehrMilliesMewesCoalescence()

virtual ~LehrMilliesMewesCoalescence ( )
inlinevirtual

Destructor.

Definition at line 176 of file LehrMilliesMewesCoalescence.H.

Member Function Documentation

◆ TypeName()

TypeName ( "LehrMilliesMewes"  )

Runtime type information.

◆ addToCoalescenceRate()

void addToCoalescenceRate ( volScalarField::Internal &  coalescenceRate,
const label  i,
const label  j 
)
virtual

Add to coalescenceRate.

Implements coalescenceModel.

Definition at line 68 of file LehrMilliesMewesCoalescence.C.

References Foam::cbrt(), sizeGroup::dSph(), Foam::exp(), Foam::mag(), Foam::max(), Foam::min(), sizeGroup::phase(), Foam::constant::mathematical::pi(), phaseModel::residualAlpha(), Foam::sqr(), Foam::sqrt(), and phaseModel::U().

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The documentation for this class was generated from the following files: