The development and mitigation of backdraft: a real-scale shipboard study

This paper presents the results of a real-scale experimental test series to study the development and mitigation of backdrafts. Experiments consisted of creating backdrafts onboard a US Navy test ship, ex-USS SHADWELL. This s tudy has shown that the key parameter for backdraft development is the fuel mass fraction. The results show that the critical fuel mass fraction, Y-f, required for the development of diesel fuel backdraft is 0.16 for fully vi tiated conditions. The effects of varying adjacent room boundaries and vent ilation conditions are discussed. In general, the intensity of a backdraft is more dependent on the adjacent boundaries than on the ventilation condit ions. The injection of water spray into the fire compartment was shown to b e an effective mitigating tactic that was able to completely suppress backd rafts primarily by means of diluting the atmosphere and reducing the fuel m ass fraction, rather than by a thermal mechanism of cooling. (C) 1999 Elsev ier Science Ltd. All rights reserved.