Analysis of correlation dimensionality of the state of a gas medium at early ignition of materials

Abstract

We have considered the application of the method of nonlinear dynamic systems in order to analyze and detect the structural patterns in the dynamics of increments in the state of a gas medium generated by early ignitions of materials in a non-sealed chamber. The research method is based on analysis of the correlation dimensionality of increments in the state of a gas medium during ignition of materials. We have theoretically justified the method for evaluating the dynamics of correlation dimensionality of increments in the state of a gas medium at ignition. The considered method for CD evaluation is based on the computation of the Grassberger-Procaccia correlation integral, applied to the gas medium state increments using a sliding window with a fixed width. That allowed us to derive a current estimate of CD increments in the state of the gas medium during ignition of flammable materials in a chamber synchronized with the observation data acquisition rate. We have analyzed the dynamics of correlation dimensionality of increments in the state of a gas medium at early ignition of alcohol, paper, wood, and textiles in a simulation chamber. It was established that for the investigated state of the gas medium during ignition of various examined materials, the dynamics of correlation dimensionality is within 0.1 to 0.6. It is noted that this fact testifies to the fractal structure of the considered increments in the state of a gas medium in a chamber and its chaotic dynamics at the emergence of ignition sites of tested materials. In this case, the fractal structure is not the same, suggesting a "transitional chaos" in the examined state of the gas medium. It was established that current estimates of the correlation dimensionality of increments in the state at the time of materials ignition tend to a sharp increase. A given fact can be used to reliably detect early fires indoors. The results obtained are important for the in-depth studying and understanding of patterns in the structure of dynamics of increments in the state of a gas medium at early ignition. It has been shown the increments in the states of a gas medium at premises characterize it as a chaotic dynamic system with a small fractal dimensionality as opposed to the traditional approach assuming a gas medium being either deterministic or random system