title: Effects of nonlinear interfacial kinetics and interfacial thermal resistance in planar solidification.
abstract: Large temperature discontinuities were recently measured at a solid-liquid interface during heat transport processes. These observations suggest that when heat flows between two phases, the interface is not well characterized by assuming thermal equilibrium. This can be of importance in rapid solidification processes. In this paper we consider a planar front model that solidifies from its undercooled melt. We use a generalized interfacial boundary condition that includes nonlinear kinetic effects and allows for a temperature discontinuity. The effects of the new boundary condition on the solidification rates and the temperature profile are reported as a function of time. Our analysis shows that the undercooling regime where constant phase-front velocities are observed at steady states (traveling-wave solutions) are unaffected by the new boundary conditions. These solutions arise when the Stephan number is larger than 1. On the other hand, the solidification rates and the steady-state velocities are greatly affected by the assumed conditions at the interface. Incorporation of an interface thermal resistance, or Kapitza resistance, generates temperature discontinuities at the interface, leads to reduced solidification rates and the Mullins-Sekerka instability arises at longer wavelengths deformation of the planar front.
authors.affiliation: Canadian Space Agency, 6767 Route de l'Aéroport, St-Hubert, Canada J3Y 8Y9.
authors.forename: Benoit
authors.initials: B
authors.lastname: Palmieri
authors.forename: C A
authors.initials: CA
authors.lastname: Ward
authors.forename: Marcus
authors.initials: M
authors.lastname: Dejmek
mesh_terms: D003198:Computer Simulation; D004735:Energy Transfer; D008962:Models, Theoretical; D013499:Surface Properties; D013696:Temperature; D013814:Thermal Conductivity; D013816:Thermodynamics