Experimental-theoretical determining of the interphase heat transfer coefficient in the process of combustion of a granular SHS mixture in a gas flow

In the process of the combustion of combined specimens of $(\rm Ti + \rm C)/($easily ignitable granules$)$ and $(\rm Ti + \rm C)/($inert particles$/($easily ignitable granules$)$ in the cocurrent flow of nitrogen, an experimental verification of the main assumption of the model of convective combustion mode according to which heating of the granule by a hot-gas flow up to the ignition temperature occurs for the time during which the granule becomes burnt down is carried out. The correctness of the calculation of the dependence of the heat transfer coefficient between nitrogen and the $\rm Ti + \rm C$ granular mixture on the gas flow rate performed by the authors is confirmed. It is shown that the values of the heat transfer coefficient obtained ensure the possibility of conversion of combustion from the conductive (filtration) mode to the convective mode when increasing the nitrogen flow rate. By the example of combustion of the $\rm Ti + 0.5\rm C$ mixture in the flow of nitrogen, the predictive value of the developed approach that allows explaining the existence of the convective mode of combustion and determining the limits of its realization is demonstrated. The proposed calculation method can be used to estimate the coefficient of interphase heat transfer in porous media.