Simulation of melting processes with AcuSolve
Altair EmployeeNew functionalities in AcuSolve now allow to simulate melting processes efficiently and with minimal user settings. The modeling of both liquid and solid phases is achieved by a simple porous medium approach having a temperature-dependent effectiveness. Below melting temperature, the effectiveness of the porous medium is very high so that fluid essentially behaves as a solid hosting heat conduction. Above melting temperatures, the effectiveness of the porous medium becomes negligible and the fluid behaves as a liquid in which natural convection greatly accelerates heat transfer.
The following video shows the melting of a frozen urea mixture in a tank that is warmed up by a hot coiled pipe. The grey surface shows the propagating solid-liquid interface as the urea mixture is warmed up by the heat from the pipe. Note that the video is not in real-time (the entire process takes almost 2 hours).
AcuSolve also features a unique dual time-stepping approach which can significantly speed up flow-thermal simulations when there exists a clear separation between the flow and thermal time scale. In the case shown in the above video, the thermal process of melting occurs over one to several hours, while natural convection in the liquid has a much smaller time scale. Using the dual time-stepping approach allows to accurately predict the melted fraction of urea with time while reducing simulation time by a factor 3.
Details about the porous medium approach to simulate melting, validation cases (including the urea tank case shown above), and the dual time-stepping method can be found in the following Altair Community knowledge article Urea melting with AcuSolve.