Research published in the Fire Safety Journal issue 151 explores correlations between small-scale and large-scale testing methods for firefighting foams.
Conducted by the U.S. Naval Research Laboratory and collaborators, the study aimed to determine if small-scale testing could effectively predict large-scale fire suppression performance.
Bench-scale testing offers significant advantages in resource efficiency and scalability compared to large-scale methods, which require extensive fuel and specialized facilities.
By comparing metrics such as extinction times and foam application rates, the study identifies promising correlations, albeit with limitations caused by experimental variances and data gaps.
The study used locally weighted regression (LWR) to correlate large-scale fire suppression metrics, such as those from MIL-PRF-24385 standards, with various small-scale test parameters.
Among the evaluated metrics were the area under the curve (AUC) for extinction profiles, extinction times for specific foam flow rate ranges, and CO2-based extinction times derived from gas profile measurements.
Bench-scale testing showed a stronger correlation when foam application rates exceeded 1500 mL/min, suggesting a compensatory relationship for passive versus active suppression methods.
However, the predictive reliability was lower in certain flow rate ranges, highlighting areas for methodological refinement.
Large-scale tests, such as the 1.8-meter pool fire standard, involve active suppression methods, whereas bench-scale tests use passive methods with smaller, controlled setups.
Foam generation techniques also differ significantly, with large-scale methods producing finer and slower-draining foam structures compared to the bench-scale approach.
These experimental differences impacted correlations, as variations in heat feedback, foam composition, and application methods influence extinction times.
Nonetheless, the study demonstrates that well-designed bench-scale tests can provide valuable insights into large-scale performance.
Despite moderate correlations, the findings emphasize the importance of small-scale testing as a cost-effective screening tool for foam formulations.
Bench-scale tests allow researchers to explore diverse chemical compositions and optimize formulations before progressing to large-scale trials, which are resource-intensive.
Future work aims to enhance the correlation between scales by refining data accuracy and expanding test datasets.
Incorporating advanced metrics, such as gas species profiles and heat flux measurements, may improve predictability and establish a more robust link between bench and large-scale results.
Research detailed in Fire Safety Journal explores correlations between small-scale and large-scale testing of firefighting foams.
Bench-scale tests demonstrated potential as predictive tools for large-scale performance, particularly when foam application rates exceeded 1500 mL/min.
While variations in testing methods and experimental setups limited correlation strength, the study highlights the utility of bench-scale tests for resource-efficient screening of foam formulations.
Future improvements in data accuracy and testing methodologies could further bridge the gap between these scales.
