Abstract

The onset of convection in a bottom heated horizontal fluid layer containing two different phases is investigated with emphasis on the effect of the location of the phase change interface. A general analysis, applicable when the phase boundary is at any location in the layer, is used to determine how both exothermic and endothermic phase changes influence layer instability. A perturbation analysis is presented for phase change boundaries close to the bottom of the fluid layer. Stability of the layer depends on three dimensionless parameters: R α , a latent heat parameter; S, a phase boundary distortion parameter; and ξ , a phase boundary location parameter. Both exothermic and endothermic phase changes can be either stabilizing or destabilizing depending on S and R α . Application is made to the exothermic olivine–spinel (in Earth and Mars) and perovskite–post-perovskite (in Earth) phase transitions and the endothermic spinel–perovskite phase change (in Earth). The perturbation analysis provides a quantitative analytic criterion to predict whether a phase change near the lower boundary is stabilizing or destabilizing. When the exothermic phase change is stabilizing (destabilizing), the layer is most stable (unstable) when the phase change is in the middle.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.