8. 1 Overview of Phase Change Modeling in FLUENT
FLUENT can be used to work out uid ow jobs affecting stage
alteration taking topographic point at one temperature e. g. . in pure metals or over a scope of temperature e. g. . in binary metals. Alternatively of explicitly tracking the liquid-solid forepart as the stage alteration occurs. which requires a traveling mesh methodological analysis. an enthalpy-porosity preparation is used where the ow and enthalpy equations are solved with excess beginning footings on the xed grid. Marangoni shear. due to the fluctuation of surface tenseness with temperature. is of import in many industrial uid ow state of affairss affecting stage alteration. The stage alteration theoretical account in FLUENT provides the ability to stipulate the Marangoni gradient at a inclining surface. every bit good as an arbitrary shear at a boundary coinciding with one of the curvilineal grid lines. The theoretical account besides allows you to stipulate the convective heat transportation. radiation. and heat ux at a wall as piecewise additive pro les. multinomials. or harmonic maps. FLUENT provides the undermentioned stage alteration patterning options: Calculation of liquid-solid stage alteration in pure metals every bit good as in binary metals. Modeling of uninterrupted casting processes i. e. . pulling” of solid stuff out of the sphere.
Chapter 8 | Phase Change Simulations
Ability to stipulate an arbitrary shear at a curving boundary as a piecewise additive pro lupus erythematosus or multinomial in footings of one of the Cartesian co-ordinates. Modeling of Marangoni convection due to the fluctuation of surface tenseness with temperature. Modeling of the thermic contact opposition between frozen stuff and the wall e. g. . due to an air spread. Ability to piece a impulse beginning in each Cartesian way and or a heat beginning to imitate magnetic force old ages or heat coevals in the sphere. for illustration. Display and patching of latent heat content. pull speeds in uninterrupted casting and other relevant variables.
These patterning capablenesss allow FLUENT to imitate a broad scope of stage alteration jobs including runing. solidi cation. crystal growing and uninterrupted casting. The physical equations used for these stage alteration computations are described in the undermentioned subdivisions. Restrictions of the As mentioned above. the stage alteration preparation in FLUENT Phase Change can be used to pattern the runing freeze of pure stuffs. as Model good as metals. The liquid fraction versus temperature relationship used in FLUENT is the lever rule|i. e. . a additive relationship Equation 8. 2-3. Other relationships are possible 124. but non available in FLUENT. The undermentioned FLUENT characteristics can non be used in concurrence with the stage alteration theoretical account: Radiation Combustion Speci ed periodic mass ow Cylindrical speeds
Overview of Phase In order for you to enable the stage alteration theoretical account. the energy equaChange Modeling tion must be active. You are so required to provide extra Procedures physical invariables refering to the stage alteration job liquidus and solidus temperature. latent heat of stop deading. etc. . You may raise one of the enhanced boundary conditions that are available hundred Fluent Inc. May 10. 1997