Analysis of secondary ignition of a powder after a drop in pressure from the position of a site-pulsation mechanism of combustion

Comparative Analysis of Methods for Measuring the Transient Burning Rate. II. Research Results

“…In this case, the dimensions of the hot spots, which are luminous zones in the camera images of the propellant surface, are ≈200-250 µm (p 0 = 0.6 MPa), which agrees with data [8][9][10][11]. For the regime of complete extinction of the propellant, the hotspot nature of extinction does not manifest itself in camera records -the background of the burning surface immediately becomes uniformly dark.…”

“…The concept of the hotspot pulsating combustion regime was apparently first proposed by Sinaev [11]. According to this hypothesis, analyzed in detail in [8][9][10], the burning surface consists of separate combustion sources, which at any one time burn at significantly different rates; the burning rate of a separate source varies in time and hot spots burn out with a definite periodicity for a given pressure. In particular, in the range of the process parameters characteristic of the extinction-reignition regime, extinction occurs in a smaller or greater area of the burning surface depressurization, depending on the ratio of the number of hot spots with different burning rates before the pressure decay.…”