kineticGasEvaporation.H
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25
26Class
27 Foam::meltingEvaporationModels::kineticGasEvaporation
28
29Description
30 Considering the Hertz Knudsen formula, which gives the
31 evaporation-condensation flux based on the kinetic theory for flat
32 interface:
33
34 \f[
35 Flux = C \sqrt{\frac{M}{2 \pi R T_{activate}}}(p - p_{sat})
36 \f]
37
38 where:
39 \vartable
40 Flux | mass flux rate [kg/s/m2]
41 M | molecular weight
42 T_{activate} | saturation temperature
43 C | accommodation coefficient
44 R | universal gas constant
45 p_{sat} | saturation pressure
46 p | vapor partial pressure
47 \endvartable
48
49 The Clapeyron-Clausius equation relates the pressure to the temperature
50 for the saturation condition:
51
52 \f[
53 \frac{dp}{dT} = - \frac{L}{T (\nu_v - \nu_l)}
54 \f]
55
56 where:
57 \vartable
58 L | latent heat
59 \nu_v | inverse of the vapor density
60 \nu_l | inverse of the liquid density
61 \endvartable
62
63
64 Using the above relations:
65
66 \f[
67 Flux =
68 2 \frac{C}{2 - C}
69 \sqrt{\frac{M}{2 \pi R {T_activate}^3}} L (\rho_{v})
70 (T - T_{activate})
71 \f]
72
73 This assumes liquid and vapour are in equilibrium, then the accommodation
74 coefficient are equivalent for the interface. This relation is known as the
75 Hertz-Knudsen-Schrage.
76
77 Based on the reference:
78 - Van P. Carey, Liquid-Vapor Phase Change Phenomena, ISBN 0-89116836,
79 1992, pp. 112-121.
80
81
82Usage
83
84 Example usage:
85 \verbatim
86 massTransferModel
87 (
88 (liquid to gas)
89 {
90 type kineticGasEvaporation;
91 species vapour.gas;
92 C 0.1;
93 isoAlpha 0.1;
94 Tactivate 373;
95 }
96 );
97 \endverbatim
98
99 where:
100 \table
101 Property | Description | Required | Default value
102 C | Coefficient (C > 0 for evaporation, C < 0 for
103 condensation) | yes
104 includeVolChange | Volumen change | no | yes
105 isoAlpha | iso-alpha for interface | no | 0.5
106 Tactivate | Saturation temperature | yes
107 species | Specie name on the other phase | no | none
108 \endtable
109
110SourceFiles
111 kineticGasEvaporation.C
112
113\*---------------------------------------------------------------------------*/
114
115#ifndef meltingEvaporationModels_kineticGasEvaporation_H
116#define meltingEvaporationModels_kineticGasEvaporation_H
117
118#include "InterfaceCompositionModel.H"
119
120// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *//
121
122namespace Foam
123{
124
125// Forward Declarations
126class phasePair;
127
128namespace meltingEvaporationModels
129{
130
131/*---------------------------------------------------------------------------*\
132 Class kineticGasEvaporation Declaration
133\*---------------------------------------------------------------------------*/
134
135template<class Thermo, class OtherThermo>
136class kineticGasEvaporation
137:
138 public InterfaceCompositionModel<Thermo, OtherThermo>
139{
140 // Private Data
141
142 //- Evaporation coefficient
144
145 //- Activation temperature
146 const dimensionedScalar Tactivate_;
147
148 //- Molar weight of the vapour in the continuous phase
150
151 //- Interface area
152 volScalarField interfaceArea_;
153
154 //- Heat transfer coefficient
155 volScalarField htc_;
156
157 //- Mass source
158 volScalarField mDotc_;
159
160 //- Interface Iso-value
161 scalar isoAlpha_;
162
163
164 // Private Member Functions
165
166 //- Update interface
167 void updateInterface(const volScalarField& T);
168
169
170public:
171
172 //- Runtime type information
173 TypeName("kineticGasEvaporation");
174
175
176 // Constructors
177
178 //- Construct from components
180 (
181 const dictionary& dict,
182 const phasePair& pair
183 );
184
185
186 //- Destructor
187 virtual ~kineticGasEvaporation() = default;
188
189
190 // Member Functions
191
192 //- Explicit total mass transfer coefficient
193 virtual tmp<volScalarField> Kexp
194 (
195 const volScalarField& field
196 );
197
198 //- Implicit mass transfer coefficient
199 virtual tmp<volScalarField> KSp
200 (
201 label modelVariable,
202 const volScalarField& field
203 );
204
205 //- Explicit mass transfer coefficient
207 (
208 label modelVariable,
209 const volScalarField& field
210 );
211
212 //- Return Tactivate
213 virtual const dimensionedScalar& Tactivate() const noexcept
214 {
215 return Tactivate_;
216 }
217
218 //- Add/subtract alpha*div(U) as a source term
219 //- for alpha, substituting div(U) = mDot(1/rho1 - 1/rho2)
220 virtual bool includeDivU() const noexcept
221 {
222 return true;
223 }
224};
225
226
227// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
228
229} // End namespace meltingEvaporationModels
230} // End namespace Foam
231
232// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
233
234#ifdef NoRepository
235# include "kineticGasEvaporation.C"
236#endif
237
238// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
239#endif
240
241// ************************************************************************* //
Base class for interface composition models, templated on the two thermodynamic models either side of...
A list of keyword definitions, which are a keyword followed by a number of values (eg,...
Definition: dictionary.H:126
Considering the Hertz Knudsen formula, which gives the evaporation-condensation flux based on the kin...
virtual tmp< volScalarField > Kexp(const volScalarField &field)
Explicit total mass transfer coefficient.
virtual tmp< volScalarField > KSu(label modelVariable, const volScalarField &field)
Explicit mass transfer coefficient.
virtual const dimensionedScalar & Tactivate() const noexcept
Return Tactivate.
kineticGasEvaporation(const dictionary &dict, const phasePair &pair)
Construct from components.
TypeName("kineticGasEvaporation")
Runtime type information.
virtual tmp< volScalarField > KSp(label modelVariable, const volScalarField &field)
Implicit mass transfer coefficient.
const phasePair & pair() const
The phase pair.
modelVariable
Enumeration for variable based mass transfer models.
Description for mass transfer between a pair of phases. The direction of the mass transfer is from th...
Definition: phasePair.H:56
A class for managing temporary objects.
Definition: tmp.H:65
rDeltaTY field()
Namespace for OpenFOAM.
dimensioned< scalar > dimensionedScalar
Dimensioned scalar obtained from generic dimensioned type.
GeometricField< scalar, fvPatchField, volMesh > volScalarField
Definition: volFieldsFwd.H:82
const direction noexcept
Definition: Scalar.H:223
dictionary dict
#define TypeName(TypeNameString)
Declare a ClassName() with extra virtual type info.
Definition: typeInfo.H:73