Hot Gas Layer Compartment Temperature Calculator

This tool calculates a steady-state hot gas layer (HGL) temperature as a function of heat release rate (HRR) at a given time based on the correlation by McCaffrey, Quintiere, and Harkleroad (MQH).

The thermal penetration time (s) through the wall is calculated by \delta^2 / (4 \alpha).

If the input time is less than the thermal penetration time (t < t_p), then the effective heat transfer coefficient is calculated by h_k = \sqrt{k \rho c/t}.

If the input time is greater than or equal to the thermal penetration time (t >= t_p), then the effective heat transfer coefficient is calculated by h_k = k / \delta.

The total wall area (m2) is calculated by (2LW) + (2LH) + (2WH) - A_o.

The hot gas layer temperature MQH correlation is given by T_g = 6.85 \left( \frac{\dot Q^2}{A_o \sqrt H_o h_k A_T}\right) ^{1/3} + T_\infty.

More information on the above equations can be found in the textbook Enclosure Fire Dynamics by Karlsson and Quintiere.

 

This calculator is powered by the free and open source tools Python, Numpy, and matplotlib, and the source code is freely available here.

Please send any bug reports or comments to me at koverholt@gmail.com.