Experimental and numerical investigation of the electrophysical properties of products of combustion of hydrogen in oxygen seeded with alkali metals

Results are given of experimental and numerical investigations of electrical conductivity and mobility of electrons in the products of combustion of hydrogen-oxygen fuel seeded with cesium or potassium-sodium eutectic. The experiments were performed in model (flow rate of $0.9$ kg/s, thermal power $N_\mathrm{th}\approx7$ MW) and large-scale experimental (flow rate $\approx12$ kg/s, $N_\mathrm{th}\approx150$ MW) facilities with the pressure in the combustor ranging from $2$ to $6$ MPa, oxidizer excess coefficients of $0.6$ to $1.1$, mass fractions of the seed in the fuel of $0.3$ to $0.9$ with the Mach number $\mathrm{М}\approx2.4$. The basic characteristics, structural schemes, and general views of the facilities are given. When cesium is used for seeding, the experimentally obtained values of electrical conductivity may be as high as $\sigma_{\mathrm{el}}\approx20$ S/m, those of $\sigma_{\mathrm{el}}\nu^2\approx115$ S/m (km/s)$^2$, and of electron mobility – $0.11$ T$^{-1}$ at a pressure of $\approx0.3$ MPa, temperature of $\approx2800$ K, and flow velocity $\nu\approx2500$ m/s. Under the same conditions for combustion products seeded with $\mathrm{KNa}$ eutectic, we have $\sigma_{\mathrm{el}}\approx9$ S/m, $\sigma_{\mathrm{el}}\nu^2\approx65$ (S/m)(km/s)$^2$, and electron mobility of $0.09$ T$^{-1}$.