Journal of Civil Protection

Fire modeling of pitched roof combustion

Ivan I. Palevoda — 2026-02-25

Purpose. To develop a physico-mathematical model and to determine the regularities of thermal and gas-dynamic interaction during the combustion of pitched roofs made of combustible building materials using computational fluid and gas dynamics methods. The processes of convective and radiative heat flux formation are to be considered in order to further refine the geometric parameters of the radiating surface and to assess the thermal impact on adjacent buildings and structures.

Methods. Numerical simulation of pitched roof combustion in ANSYS Fluent 2022 R2. The calculations were made using the SST k–ω turbulence model, a turbulent combustion model incorporating the eddy dissipation model, the discrete ordinates method for radiative heat transfer, a pyrolysis model for roofing materials, and a single-step soot formation model. Boundary conditions were specified based on previously conducted experimental studies.

Findings. Spatial-temporal distributions of temperature fields and heat flux intensities during pitched roof combustion were obtained. Based on the results of numerical simulations performed in the ANSYS Fluent software environment, it was established that during roof combustion, at a distance of 1 m horizontally and 1 m vertically from the gable and the roof slope, the temperature values range from 530 to 590 K, while the heat flux density varies from 4.5 to 8.0 kW/m². The obtained data are in good agreement with the results of experimental studies, confirming the validity of the model. The processes of pyrolysis, turbulent combustion, radiative heat transfer, and soot formation in the modeling of pitched roof combustion were comprehensively investigated.

Application field of research. Determination of fire separation distances between buildings with roofs made of combustible materials. The obtained data can be used to improve engineering methodologies and fire safety regulatory documents and are also of practical interest to engineering organizations, design institutes, personnel of the MES, research and educational institutions.

Engineering method for calculating the temperature field in the cross-section of hollow-core reinforced concrete slabs under a standard fire

Denis S. Nekhan' — 2026-02-25

Purpose. To develop an engineering methodology for calculating the temperature field in the cross-section of hollow-core reinforced concrete slabs (150–250 mm thick) with symmetrically located (relative to the center of gravity) closed circular hollows (40 to 60 % volume) under unilateral standard fire exposure. This methodology is based on adapting a simplified solution to the nonlinear heat conduction equation for solid slabs using correction factors obtained through numerical modeling and taking into account the cross-sectional geometry, point coordinates, and heating duration.

Methods. Numerical modeling of heating of reinforced concrete slabs during a standard fire using the finite element method based on the design of a full factorial experiment. This study summarizes the modeling results and analyzes the influence of the geometric parameters of cross-section of the hollow-core slabs and the duration of standard fire exposure on the temperature field generated within the slabs. An existing methodology for calculating the temperature field in solid slabs exposed to a standard fire is adapted for application to hollow-core slabs.

Findings. The influence of the geometric parameters of hollow-core reinforced concrete slabs (thickness, volume of enclosed circular cavities) on the temperature field dynamics in the cross-section (at a depth of up to 0.3 of the structure's thickness) under unilateral standard fire exposure lasting from 30 to 180 minutes was determined. A regression equation was derived for determining the khol coefficient, which accounts for the temperature increment at a given distance from the heated surface in hollow-core slabs compared to their solid counterparts under unilateral standard fire exposure. An engineering methodology for assessing the temperature field in hollow-core reinforced concrete slabs (150–250 mm thick with a volume of enclosed circular hollows of 40–60 %) under standard fire exposure was developed.

Application field of research. The research results can be used by specialists on design, expert, and scientific organizations to solve simplified heat engineering problems of fire resistance for hollow-core reinforced concrete slabs, as well as to improve existing regulatory legal acts.

Influence of various operating conditions of a compressed air breathing apparatus on the stability of the lung demand valve

Vyacheslav V. Lakhvich — 2026-02-25

Purpose. To experimentally evaluate the influence of various operating conditions of a compressed air breathing apparatus on the stability of the operation of the lung demand valve of a compressed air breathing apparatus.

Methods. Empirical research methods included experimentation and measurement. Theoretical methods included analysis and synthesis of literary sources, as well as statistical processing and generalization of the obtained experimental data.

Findings. Based on operational tests, it was established that a decrease in ambient temperature (down to -3 °C) in conditions of high humidity and simulated exposure to water aerosol (while fire extinguishing) leads to increased inhalation effort. As work intensity increases, breathing becomes more difficult due to the increased amount of air to be consumed, and in some cases, impossible. The primary cause of failure is icing of the inhalation valve seat and plate, leading to their mechanical sticking and complete blockage of air supply to the sub-mask space, as well as to disruption of the continuity of air supply to the sub-mask space.

Application field of research. The research results can be used by the Ministry of Emergency Situations in developing recommendations for the safe use of breathing apparatus in low-temperature conditions: monitoring and preventing icing, and actions at the first signs of increased breathing disruption.

Mathematical model for predicting the expansion rate of fire extinguishing foam produced in devices with meshes

Andrey N. Kamlyuk — 2026-02-25

Purpose. Based on the results of experimental studies, a mathematical model is developed for predicting the foam multiplicity, taking into account the main parameters of the foam formation process on the grids of foam-generating devices.

Methods. The general methodology of the work included the theoretical (analysis, synthesis, comparison) and experimental research methods. The foam expansion rate was determined experimentally using the developed method. Processing of experimental data and creation of a mathematical model included the use of statistical regression analysis.

Findings. As a result of the research, experimental data were obtained on the dependence of the foam multiplicity on a number of parameters of the foaming process on the mesh of foam-generating devices (mesh cell size, distance from nozzle outlet to mesh, nozzle outlet diameter, foaming solution flow velocity and its properties). In particular, to take into account the size of the mesh cell, a generalized parameter K_m was used, reflecting the proportion of the part filled with wire from the entire surface area of the mesh. The flow velocity of the foaming solution and its properties are taken into account using the capillarity number Ca. Based on the analysis and generalization of the obtained data, the mathematical model was developed for predicting the expansion rate of fire-extinguishing foam, reflecting the listed parameters of foam formation on the meshes. The predicted values according to the developed model coincide with the experimental values (analysis of residuals confirmed the adequacy of the model). The average error in calculating the foam expansion ratio is less than 10 %.

Application field of research. Design and operation of foam-generating devices with meshes. The proposed model allows for the selection of the required foam-generating device configuration taking into account the foam concentrate used and the foam solution flow conditions to produce the most effective fire extinguishing foam.

Multifactor model for optimizing the composition of a complex flame retardant for polyamide-6

Olga V. Reva — 2026-02-25

Purpose. Development of an adequate mathematical model of the composition of a complex flame retardant for polyamide-6 with a given reduction limit and its application to determine the optimal characteristics of the flame retardant composition (ensuring fire resistance of the resulting composite material of category PV-0 and a reduction in the main physical and mechanical characteristics by no more than 8–10 % compared to the original polyamide).

Methods. Theoretical methods of statistical analysis of the experimental results were used to obtain a regression model and test its statistical significance and adequacy as well the method of cross-sections of the discriminant function in the plane of the most important factors identified by regression analysis. Statistica (TIBCO Software Inc.) and PTC Mathcad Prime (PTC Inc.) were used for calculations.

Findings. An experimental study and statistical analysis of the obtained data were conducted. Using regression and discriminant analysis methods, a multi-level mathematical model was developed. This model describes the dependence of the fire resistance parameters and mechanical properties of a fire-resistant polymer composite on the total concentration of a complex flame retardant in the polyamide matrix and the relative content of its five components. The coefficients in the regression equation were determined. A comprehensive mathematical model was developed that allows for the identification of the optimal composition of a multi-component flame retardant, taking into account the priority values of the fire-resistant polymer composite's performance parameters.

Application field of research. The developed mathematical model allows us to determine the optimal composition of a complex flame retardant for heat-proof polymers and its concentration in a polymer composite in accordance with the requirements for its most important operational parameters: fire resistance of category PV-0 with a minimal reduction in physical and mechanical properties.

A comprehensive methodology for assessing the effectiveness of fire suppression with foam based on the quality of fire suppression and economic feasibility

Andrey N. Kamlyuk — 2026-02-25

Purpose. To develop a comprehensive methodology for evaluating the fire suppression effectiveness of low-expansion air-mechanical foam and conduct field testing of foam generating devices. To evaluate the cost-effectiveness of using low-expansion air-mechanical foam.

Methods. The fire extinguishing efficiency of foam generated by various devices was assessed experimentally, and the obtained experimental data was processed using the method of estimating and expressing the uncertainty of measurements.

Findings. A comprehensive methodology for evaluating the fire extinguishing efficiency of low-expansion air-mechanical foam has been developed. To determine the extinguishing efficiency, comparative tests were conducted: for foam generators – SVP and SVP-2 nozzles, NVP-11/0.6 U1 water-foam nozzle for the SRK-50 fire nozzle and air-foam nozzle for the SPRUK 50/0.7 fire nozzle; for compression foam generating systems – SPRU 50/0.7 fire nozzles and Elkhart Brass ST-185A with compression foam delivery; for automatic fire extinguishing systems – V2, TY 3251, DPU-15, DVN-11 sprinklers. Evaluation of economic efficiency demonstrates the feasibility of using low-expansion air-mechanical foam in extinguishing fires and allows choosing the optimal means for eliminating emergency situations both in terms of safety and cost savings.

Application field of research. The developed methodology for evaluating the fire suppression effectiveness of low-expansion air-mechanical foam can be applied in the development and modernization of domestic technical regulatory legal acts in this field, as well as for studying devices (including newly developed ones) for generating air-mechanical foam under conditions similar to a real fire. Furthermore, using this comprehensive methodology it is possible to select the most effective means for emergency response from a safety and cost perspective.

Neural network assistant for automated diagnostics and first aid support for eye and skin injuries in emergency situations

Gleb Yu. Shamsudinov — 2026-02-25

Purpose. Development and validation of a deep neural network for computer vision tasks, which, under conditions of limited time and resources, allows for the automatic classification of pathological conditions of the eyes and skin resulting from man-made and natural emergencies, as well as animal and insect bites, and the proposal of a first aid algorithm.

Methods. Development of a deep neural network architecture, training the model on an expanded dataset of images of pathological conditions of the eyes and skin, validation of the results using standard computer vision metrics.

Findings. A deep neural network has been developed that demonstrates high accuracy in classifying eye and skin pathologies, including animal and insect bites, on an expanded dataset. A new approach to automating first aid in emergency situations has been presented, which allows for reducing diagnostic time and increasing accuracy in various conditions, including the Ministry of Emergency Situations' activities to eliminate biological and social risks in disaster zones.

Application field of research. The obtained results can be used to implement the model in first aid systems during emergencies, mobile applications and devices for rescuers, as well as to solve other problems in the field of life safety.

Bolting operability in fasteners of tilting support device cranes

Olga O. Smillovenko — 2026-02-25

Purpose. Improving the operability of bolted connections of support and turning devices of cranes by early detection of defects based on a system analysis of factors (causes) affecting the failure of fasteners.

Methods. Analysis of the results of theoretical and experimental studies of the reliability of fasteners of flange connections, taking into account dynamic loads; modeling of the process of loss of functional capability of a bolted connection taking into account load redistribution.

Findings. The main reasons for the failure of bolt assemblies of lifting cranes in the form of non-cyclic dynamics of functional loads, combined impact of various types of loading, which is not taken into account in the design calculation of the thread diameter, as well as the direct influence of subjective factors, have been identified. The recommendations are formulated on the control of bolt connections (in accordance with the Rules for ensuring the industrial safety of lifting cranes), which substantiate and specify the operations for checking: tightening torque, the presence of defects (cracks) in the bolt body, surface areas affected by corrosion.

Application field of research. Installation and operation of lifting cranes equipped with a flange-type rotary support device with bolting.

Emotional burnout among firefighters

Tat'yana N. Tarasevich — 2026-02-25

Purpose. To analyze theoretical and methodological approaches to the problem of individual occupational health with the aim of introducing an independent definition of «individual occupational health». To conduct an empirical study of the occupational health of employees of emergency response agencies and units using the emotional burnout indicator.

Methods. To analyze the theoretical and methodological approaches of domestic and international scientists to the problem of individual occupational health. A.V. Boyko's «Emotional Burnout» methodology was used to study the level of emotional burnout as a component of the occupational health of employees of emergency response agencies and units.

Findings. A definition of professional health is provided as an integrated indicator of an individual's physical and mental health, characterizing their ability to maintain protective mechanisms throughout their professional life in order to achieve high performance in a given work environment. The level of emotional burnout as a component of the professional health of employees of emergency response agencies and units was studied. The emotional burnout phases of «tension», «resistance», and «exhaustion» were not developed in 80, 67 and 87 % of employees, respectively. Low or absent levels of emotional burnout indicate employees' satisfaction with working conditions and good relationships among colleagues, subordinates, and management. Employees of emergency response agencies and units possess stable self-regulation skills and psychological defense mechanisms, indicating high professional reliability and professional health.

Application field of research. The obtained results demonstrate the feasibility of using A.V. Boyko's methodology for the timely detection of increased levels of emotional burnout and subsequent correction of the psychological state, developing the emotional resilience of employees of emergency response agencies and units to maintain their professional health at a high level.

Pedagogical concept for the development of a system of interactive simulation trainers for implementing supervisory and preventive activities in the field of fire safety

Andrey V. Surikov — 2026-02-25

Purpose. To substantiate and develop a pedagogical concept for creating a system of interactive simulation training simulators aimed at increasing the effectiveness of the formation of supervisory and legal competence among future specialists of the State Supervisory Authority.

Methods. The general methodology of the work involved the use of theoretical research methods (analysis and synthesis).

Findings. A review and analysis of scientific and literary sources has been conducted, considering the principles of contextual learning, problem-based learning, cognitive load theory, andragogy, and gamification, as the basis for the pedagogical concept of creating a system of interactive simulation training devices for carrying out supervisory and preventive activities in the field of fire safety. The key principles of the system concept are presented, and the main approaches to its implementation, including the architecture, are defined. The expected educational results of implementing the concept in the educational process are formulated.

Application field of research. The research results obtained can be applied in developing scientific and methodological support aimed at forming the supervisory and legal competence of specialists in state fire supervision authorities.