CFD-Based Analysis of Heat and Mass Transfer in Human Cremation: A Numerical Simulation Approach

This study presents a multi-physics coupled three-dimension CFD combustion model to simulate heat and mass transfer during cremation. It accounts for the heterogeneous characteristics and variable thermophysical properties of the remains. Ansys Fluent, coupled with User-Defined Functions (UDFs), models the dynamic evolution of body composition, combustible substitutes, and combustion reaction stages during cremation, providing a detailed description of the process. Numerical simulations reveal three distinct cremation stages when natural gas is used: 1) The initial phase, with a furnace temperature of 800 K, features rapid water vapor release and a Leidenfrost-like vapor layer that impedes heat transfer between the high-temperature flue gas and the remains' surface. 2) The stable combustion phase, with a temperature of approximately 1100 K, shows concentrated high-temperature zones above the remains and in the furnace mid-section, demonstrating significant dependence on airflow velocity. 3) The burnout phase, characterized by a temperature decrease to 900 K as combustibles diminish. The maximum deviation between simulation results and experimental data is within 10%, which confirms the model's accuracy. This computational framework is highly applicable for simulating combustion processes involving heterogeneous materials with variable thermophysical properties.