Analysis of incident angle influence on the dispersion of fluorine-free foam extinguishing agents
To investigate the impact of incident angles on the spreading behavior of fluorine-free foam extinguishing agents,experimental tests were conducted on a typical angle.Subsequently,numerical simulations were carried out to validate the computational model,which was then utilized to simulate the spreading process at various incident angles.The findings indicate that the spreading dynamics of fluorine-free foam extinguishing agents on the oil surface are primarily governed by gravity initially and later by surface tension.Moreover,the spreading velocity controlled by surface tension is observed to be slower compared to that governed by gravity.Upon complete coverage of the oil surface by the fluorine-free foam extinguishing agent,piecewise fitting results were obtained for the spreading time and incident angle.Specifically,an exponential decline function with R2 of 0.99 was identified within the incident angle of 60° to 75° and a linear decline function with R2 of 1 was identified within the incident angle of 80° to 90°.Furthermore,the overall fitting function for all spreading times and respective incident angles exhibited an exponential decline trend with R2 of 0.99.Notably,the optimal incident angle for the fluorine-free foam extinguishing agent was determined to be at 77° based on efficiency considerations.Moreover,as the incident angle surpasses 75°,the turbulent region expands,extending beyond the oil surface area.Interestingly,for a constant incident angle,the maximum turbulent kinetic energy exhibited by the fluorine-free foam extinguishing agent on the oil surface diminishes over time.The fitting outcome correlating the maximum turbulent kinetic energy with time corresponds to a linear regression decline function with R2 of 0.99.Furthermore,as the incident angle of the foam extinguishing agent escalates,the velocity differentials across various directions diminish,and there is a fluctuation in the maximum spreading velocity—initially decreasing and subsequently increasing.The exploration into the incident angles of fluorine-free foam extinguishing agents not only presents valuable research insights but also offers a practical approach for selecting optimal angles pertaining to foam extinguishing agent applications.
万方数据
维普
