In this eleventh installment of a 14-part series of monthly articles, The Combustion Institute recognizes the 2017 Distinguished Papers selected from among the scientific papers presented during the 36th International Symposium on Combustion. Congratulations to Scott Jackson for winning the DPA in the Detonations, Explosions, and Supersonic Combustion colloquium.

The authoritative paper, The dependence of Ammonium-Nitrate Fuel-Oil (ANFO) detonation on confinement, explores methods to better measure the variation of ANFO detonation behavior and determine if models could be developed to better predict those variations.

Non-ideal explosives, especially ANFO, are the most widely used explosives in the world, predominantly for mining applications, that also exhibit extremely complex detonation behaviors. The explosive energy output and detonation velocity (collectively referred to as explosive performance) can vary significantly depending on how they are used, and this variation is currently difficult to predict. Testing and analysis has revealed the explosive performance demonstrated a very strong dependence on the material confining the explosive charge, varying with both the confiner type and thickness.

The immediate impact of the paper demonstrates a scaling relationship to relate the explosive performance to the confiner parameters. That relationship allows better prediction of the ANFO performance in different environments. In the long-term, the discovery of that scientific relationship also opens up new research paths to better understand and predict the complex detonation physics in non-ideal explosives like ANFO.

The beneficiaries of the research in the paper are numerous. Many defense applications and industrial applications will benefit from the research. Specifically, commercial mining industries that use non-ideal explosives can begin to better understand explosive performance.

The paper’s research took place in different parts of New Mexico. Specialized facilities were required for the testing that involved using explosives to accelerate large pieces of metal to over a thousand meters per second (known as a cylinder test). Most of the larger-scale testing was done at Energetic Materials Research and Testing Center (EMRTC), an affiliate of New Mexico Institute of Mining and Technology, United States. Other tests and the analysis was completed at Los Alamos National Laboratory, United States.

Most of the experimental testing was performed between 2011-2012. The analysis routine necessary to interpret the product equation of state from the test data was then developed in 2014 (published as a separate paper in 2015). That prior work provided the basis to compute and analyze the equation of state relationships in the present paper to discover the performance-confiner dependence.

About 1,300 papers were submitted to the 36th Symposium in 14 combustion science colloquia. Those papers were categorized by teams of colloquium coordinators and co-chairs, and then distributed to approximately 1,000 scientific reviewers. One paper in each discipline was awarded the recognition of Distinguished Paper.

The 14 Distinguished Papers undergo committee review for consideration to receive the Silver Combustion Medal that will be awarded during the 37th Symposium in Dublin, Ireland. A paper selected for this honor exemplifies quality, achievement, and significance to advance a field of combustion science. Distinguished papers are selected biennially from among the scientific papers presented during the International Symposium on Combustion and accepted for publication in the Proceedings of The Combustion Institute.