Heat transfer of submicron MgO particles in the combustion zone of single magnesium particles

The mechanism of heat transfer of submicron MgO particles in the combustion zone during their growth is studied at pressures of 10$^4$ – 10$^5$ Pa using opticospectral measurements and numerical simulation. It is shown that at the early stage of particle growth, heat transfer is caused exclusively by collisions with gas molecules with an energy-accommodation coefficient of $\sim$ 0.01 – 0.02. During particle growth and with decrease in pressure, the role of radiation increases, and, ultimately, radiation becomes a leading mechanism of heat transfer.