Fluent Melting and Solidification
Chapter 8. Phase Change Simulations
This chapter describes the phase change model available in FLUENT and the commands you use to set up a phase change problem. Information is organized into the following sections: Section 8.1 : Section 8.2 : Section 8.3 : Section 8.4 : Overview of Phase Change Modeling Phase Change Modeling Theory User Inputs for the Phase Change Model Solution Strategies for Phase Change Problems
8.1 Overview of Phase Change Modeling in FLUENT
FLUENT can be used to solve uid ow problems involving phase
change taking place at one temperature e.g., in pure metals or over a range of temperature e.g., in binary alloys . Instead of explicitly tracking the liquid-solid front as the phase change occurs, which requires a moving mesh methodology, an enthalpy-porosity formulation is used where the ow and enthalpy equations are solved with extra source terms on the xed grid. Marangoni shear, due to the variation of surface tension with temperature, is important in many industrial uid ow situations involving phase change. The phase change model in FLUENT provides the ability to specify the Marangoni gradient at a sloping surface, as well as an arbitrary shear at a boundary coinciding with one of the curvilinear grid lines. The model also allows you to specify the convective heat transfer, radiation, and heat ux at a wall as piecewise linear pro les, polynomials, or harmonic functions. FLUENT provides the following phase change modeling options: Calculation of liquid-solid phase change in pure metals as well as in binary alloys. Modeling of continuous casting processes i.e., pulling" of solid material out of the domain .
8-2
Chapter 8 | Phase Change Simulations
Ability to specify an arbitrary shear at a curved boundary as a piecewise linear pro le or polynomial in terms of one of the Cartesian coordinates. Modeling of Marangoni convection due to the variation of surface tension with temperature. Modeling of the thermal contact resistance
This chapter describes the phase change model available in FLUENT and the commands you use to set up a phase change problem. Information is organized into the following sections: Section 8.1 : Section 8.2 : Section 8.3 : Section 8.4 : Overview of Phase Change Modeling Phase Change Modeling Theory User Inputs for the Phase Change Model Solution Strategies for Phase Change Problems
8.1 Overview of Phase Change Modeling in FLUENT
FLUENT can be used to solve uid ow problems involving phase
change taking place at one temperature e.g., in pure metals or over a range of temperature e.g., in binary alloys . Instead of explicitly tracking the liquid-solid front as the phase change occurs, which requires a moving mesh methodology, an enthalpy-porosity formulation is used where the ow and enthalpy equations are solved with extra source terms on the xed grid. Marangoni shear, due to the variation of surface tension with temperature, is important in many industrial uid ow situations involving phase change. The phase change model in FLUENT provides the ability to specify the Marangoni gradient at a sloping surface, as well as an arbitrary shear at a boundary coinciding with one of the curvilinear grid lines. The model also allows you to specify the convective heat transfer, radiation, and heat ux at a wall as piecewise linear pro les, polynomials, or harmonic functions. FLUENT provides the following phase change modeling options: Calculation of liquid-solid phase change in pure metals as well as in binary alloys. Modeling of continuous casting processes i.e., pulling" of solid material out of the domain .
8-2
Chapter 8 | Phase Change Simulations
Ability to specify an arbitrary shear at a curved boundary as a piecewise linear pro le or polynomial in terms of one of the Cartesian coordinates. Modeling of Marangoni convection due to the variation of surface tension with temperature. Modeling of the thermal contact resistance
Links: c Fluent Inc. May 10, 1997 8.3 User Inputs for the Phase Change Model c Fluent Inc. May 10, 1997 8-12