The wave algorithm used to determine the optimal indoor route for smoke divers in case of fire and fumigation

Introduction. One of the main objectives, pursued by the information analysis support extended to smoke divers, is the preparation of indoor routes. Technical capabilities, represented by advanced remote monitoring systems, provide a fire extinguishing manager with the necessary information about the point of fire origin and mathematical tools allow to predict fire spreading characteristics. The goal of this work is to develop an algorithm for the preparation of an optimal indoor route for smoke divers to support management decisions in the event of fire. To achieve this goal, it is necessary to develop the theoretical framework and implement it in a software programme.Theoretical foundations. The theory of cellular automata is employed in this paper to simulate the routes of smoke divers inside a building. A cellular automaton with a Moore neighborhood is applied. We use differential equations, similar to the Kolmogorov equations, to monitor the fire parameters.Results and discussions. A modified wave algorithm was developed to determine the optimal indoor route. The software tool was applied to simulate the route of gas divers. Coefficients of importance were applied in the process of mathematical modeling; they took account of the prioritized work to be performed by smoke divers.Conclusions. The results of the study suggest that the algorithm allows to identify the optimal itinerary, thereby enabling the decision maker, responsible for sending teams of smoke divers to the work performance location, to make a reasonable choice of the point of entry for the personnel and machinery, as well as their itinerary inside the building.

FIRE INVESTIGATION ACTIVITY MODEL BASED ON A SCENARIO APPROACH

Purpose. Fire investigation is one of the main functions of EMERCOM of Russia. The analysis of activity results of Federal Fire Service forensic institutions based on the current model shows that the point of fire origin is not identified with sufficient accuracy in 63 % of cases, and the fire cause is not unambiguously identified in 74 % of cases. This situation makes it impossible to create an incident information model, to establish cause-and-effect relationships between the phenomena and conditions at a fire scene and also to give the correct legal qualification of the incident. The purpose of the study is to improve the efficiency and effectiveness of fire investigation activities. Methods. The study is based on the theory of system analysis, the theory of functions and the theory of risks. The authors use methods of mathematical modeling and information synthesis, instrumental methods for their support, methods of informatics, expert analysis and combinatorics. Findings. A scenario approach to organize fire investigation activities is proposed. It allows effectively identifying the circumstances of fire occurrence, fire development and negative fire consequences. The problems of the proposed approach are the need to develop a reasonable list of scenarios to be investigated under conditions of information uncertainty and the labour-consuming nature of scenario research, which requires the availability of software and powerful computers. Research application field. The use of the proposed approach will improve the accuracy of determining a fire scenario with severe thermal damage to building structures and interior items caused by fire heat as well as with uneven distribution of fire load in the compartment with the ignition source, taking into account the specific gas exchange in the compartment during a fire and other parameters. Conclusions. The proposed activity model based on the scenario approach, which includes the physical evidence investigation at a fire scene and the results of mathematical modeling of the dynamics of hazardous fire factors, enables to determine the point of fire origin and the cause of the fire and also to establish cause-and-effect relationships between the fire and negative fire consequences with sufficient accuracy.

Analysis of a Fire Case Caused by Heat Generation due to Cu2O Breeding

Although fires caused by heat generation due to Cu₂O breeding in wire connections are well-known among fire investigators, there are few papers on the analysis and introduction of fire cases by heat generation due to Cu₂O breeding. This study analyzed fire statistics caused by heat generation in electrical connections and the phenomena and features of heat generation due to Cu₂O breeding. Then, a fire which occurred in the wire connection in a university lab by heat generation due to Cu₂O breeding was analyzed in more detail. This fire case could reach a conclusion that heat generation due to Cu₂O breeding caused a fire in the wire connection through the fire pattern investigation of fire origin, the visual investigation of wire connection, 3D CT, power-on-test, and stereoscopic microscopy, SEM and EDS analysis.

Winds and Gusts during the Thomas Fire

We analyze observed and simulated winds and gusts occurring before, during, and immediately after the ignition of the Thomas fire of December 2017. This fire started in Ventura county during a record-long Santa Ana wind event from two closely located but independent ignitions and grew to become (briefly) the largest by area burned in modern California history. Observations placed wind gusts as high as 35 m/s within 40 km of the ignition sites, but stations much closer to them reported much lower speeds. Our analysis of these records indicate these low wind reports (especially from cooperative “CWOP” stations) are neither reliable nor representative of conditions at the fire origin sites. Model simulations verified against available better quality observations indicate downslope wind conditions existed that placed the fastest winds on the lee slope locations where the fires are suspected to have started. A crude gust estimate suggests winds as fast as 32 m/s occurred at the time of the first fire origin, with higher speeds attained later.