A note on possible flow instabilities in melting from the side

This paper presents a scale analysis of the parameters for which flow insta bilities can be expected in coupled phase change - natural convection in ca vities heated from the side. The results are in agreement with what was obs erved numerically for very low Prandtl number fluids, where multiple cells were found to appear early on as a result of the instability of the conduct ion regime. For very large Prandtl number flow instabilities, multiple cell s, if any, would only occur at very large nominal Rayleigh number. (C) Else vier, Paris.