Electric Diffusion Processes on a High-Temperature Turbine Blade and Its Contribution to the Aircraft Engine Current

The effect of disturbance of the electrical neutrality of flow in the channel of a jet engine is investigated, which leads to the emergence of an electric current flowing out of the engine (engine current) and, as a result, to engine electrization of the aircraft. The physicomathematical model of diffusion electric processes in the vicinity of the channel walls and of the surfaces of internal elements of the engine is improved by including the reaction of electron attachment (detachment) to (from) neutral molecules. The model problem on an electric diffusion boundary layer on a flat plate developing against the background of a gasdynamic boundary layer is treated on the assumption of the equilibrium flow of the latter reaction. A numerical simulation is performed of an electric diffusion boundary layer on a high-temperature turbine blade at a surface temperature of $1350$ K, with the charged particle concentration, the total temperature, and the Mach number in the incident flow of $10^8$ cm$^{-3}$, $1600$ K, and $0.35$, respectively, and the total pressure in the incident flow of $5$ and $10$ atm. The value of an electric current flowing into the gasdynamic wake behind the blade is $\simeq1$ $\mu$A, which, in the presence of a large number of blades in a turbine, gives the real value of the engine current of $20$ to $50$ $\mu$A measured under fullscale conditions.