Role of pressure waves in the heating of the end-gas in HCCI engine with activation by pulsed corona discharge

In this paper we present numerical research of pressure waves influence on the end-gas in HCCI engine with discharge activation. It is shown that there is certain promotion of exothermic chemical reactions by pressure waves. That leads to the slight heating of the end-gas, but mainly the end-gas is heated due to the compression in the process of combustion wave propagation.

PROPAGATION OF THE BURNING WAVE IN A PULSED DETONATION COMBUSTOR OPERATING ON MIXTURES OF HEPTANE AND JET A-1 WITH AIR AND OXYGEN AT [O2/AIR] < 1

This work is devoted to the study of the dynamics of combustion wave propagation in oxygen-enriched mixtures of n-heptane with air and jet fuel "Jet A-1" in a small-size pulsed detonation combustor (PDC) with a diameter of 20 mm and a length less than 1 m. Experiments are carried out after the PDC reaches a stationary thermal regime when changing the equivalence ratio (ϕ = 0.73-1.89) and the oxygen-to-air ratio ([O2/air] = 0.15-0.60). The velocity of the combustion wave is determined by measuring the propagation time of the flame front between adjacent pressure sensors that form measurement segements along the PDC.

Combustion Synthesis of Chromium Nitrides

This paper explores different modes of synthesis by combustion of chromium-nitrogen and ferrochromium-nitrogen alloys. The SH-synthesis of chromium nitrides and ferrochromium nitrides was performed. Regular patterns in layer-by-layer and surface modes of Cr combustion in nitrogen were investigated. The mechanism of non-stationary combustion during the synthesis of chromium was investigated. Regular patterns of chromium and ferrochromium combustion in the cocurrent filtration mode were analyzed, and the possibility to intensify the SHS process using the pressure filtration principle was assessed. The process of chromium powder combustion in the cocurrent flow of nitrogen-containing gas in the range of specific flow rates from 20 cm3/s·cm2 was investigated. Pressure filtration intensifies the process of combustion wave propagation in the Cr–N2 system. Here, the combustion rate increases while the degree of nitridation decreases. We discovered superadiabatic heating modes when the reaction zone was blown with pure nitrogen and a nitrogen-argon mixture. The tempering mode that was realized during pressure filtration allows for the uptake of high-temperature single-phase non-stoichiometric phases of Cr2N.