Eulerian two-phase flow simulation and experimental validation of semisolid slurry generation process using cooling slope

Abstract

Experimental and numerical studies of slurry generation using a cooling slope are presented in the paper. The slope having stainless steel body has been designed and constructed to produce semisolid A356 Al alloy slurry. The pouring temperature of molten metal, slope angle of the cooling slope and slope wall temperature were varied during the experiment. A multiphase numerical model, considering liquid metal and air, has been developed to simulate the liquid metal flow along the cooling channel using an Eulerian two-phase flow approach. Solid fraction evolution of the solidifying melt is tracked at different locations of the cooling channel following Schiel’s equation. The continuity, momentum and energy equations are solved considering thin wall boundary condition approach. During solidification of the melt, based on the liquid fraction and latent heat of the alloy, temperature of the alloy is modified continuously by introducing a modified temperature recovery method. Numerical simulations has been carried out for semisolid slurry formation by varying the process parameters such as angle of the cooling slope, cooling slope wall temperature and melt superheat temperature, to understand the effect of process variables on cooling slope semisolid slurry generation process such as temperature distribution, velocity distribution and solid fraction of the solidifying melt. Experimental validation performed for some chosen cases reveals good agreement with the numerical simulations.

Keywords:

• Semisolid slurry
• Cooling slope
• A356 alloy
• Eulerian model
• Two-phase flow

The authors would like to thank DST, New Delhi, for their financial support to the present work. The authors express their heartfelt gratitude to Dr G. Biswas, Director, CSIR-CMERI, Durgapur, for his continuous encouragement and all the members of Foundry group, especially Mr B. R. K. Venkatapathi, Mr T. Roy and Mr J. Bindhani, for their cooperation for the successful completion of the present research work.