Numerical Analysis and Experiments of Convective Heat Flow in Fire Compartment

Abstract

Theoretical and experimental numerical analysis shows the capabilities of finite difference calculations of fine induced natural convective heat flow in a fire compartment. The viscous, heat conductive, compressible fluid is represented using a K-ε model. Because a two-point upwind difference scheme gives numerical viscosity, the computational results are suspect at large velocities. The practical stability limits and truncation errors for finite difference equations approximating fire flows have been analyzed. The sensitivities of numerical solutions have been evaluated by the theoretical and experimental numerical analysis. Based on results of numerical experiments we propose a reasonable time interval and space mesh size criteria which also considers CPU time. Furthermore, we have introduced the effective maximum cell Reynolds number (Re∗) for the equation of motion, or the effective maximum cell Peclet number (Pe∗) for the equation of energy. We propose that the values of Re∗ and Pe∗ indicate the trust which may be placed on the approximate solutions.