Approval of a computational method for determining thermal loads during accidents accompanied by fireballs

Introduction. Large fires are quite often accompanied by the formation of fireballs (OSH), which create significant thermal loads. As a result of the fire coverage of a container containing an overheated liquid, a physical explosion occurs, which releases a significant amount of fuel forming a fireball. This phenomenon is dangerous because, with a short lifetime, it is capable of causing thermal injuries over considerable distances. The existing methods of predicting the consequences of a fireball, set out in various domestic regulatory documents and foreign literature, do not fully reflect the possible values of thermal loads. In this regard, a computational method for determining thermal loads was developed, taking into account the movement of the fireball.

Goals and objectives. The purpose of this study is to test the developed computational methodology for determining thermal loads, which takes into account the kinematic characteristics of the fireball. The following tasks were solved in the study:

• ● check the operability of the fireball lifting model;
• ● to conduct a comparative analysis of thermal loads according to the developed methodology with the results of calculation of domestic and foreign methods;
• ● conduct a computational experiment on the effect of air mobility (wind effect of 7 m/s) on thermal loads.

Research methods. To check the operability of the OSH lifting model, footage of the formation of a fireball was used. According to the shooting frames, the position of the fireball in space and its kinematic characteristics were tracked. Using kinematic parameters, thermal loads were determined. To assess the adequacy of calculations of thermal loads, a comparative analysis of the results of calculations of the developed computational methodology with the results of calculations using existing domestic and foreign methods was used. To substantiate the application of the developed computational methodology for determining thermal loads, taking into account the kinematic parameters of the fireball, a computational experiment was conducted using the MATLAB software and computing complex.

Results and their discussion. The results of the calculation of kinematic parameters are satisfactorily correlated with the results of mathematical modeling. The obtained values of thermal loads according to the developed computational methodology are in satisfactory agreement with the results of calculations according to existing domestic and foreign methods. Based on the calculations performed in the article, it is shown that a change in gas dynamic flows (wind demolition) leads to a significant change in the damaging factors of fireballs that are formed during fires in emergency situations.

Conclusions. The results of the research made it possible to assess the adequacy of the performance of the improved computational methodology for determining thermal loads in accidents accompanied by fireballs, as well as to justify the relevance of the application of the developed method.

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