Uncertainty analysis of deflagration-to-detonation run-up distance

Three methods were adopted to estimate the deflagration-to-detonation run-up distance in a smooth tube, which comprises of (1) the measurement of the propagation speed of pressure or combustion waves compared with the C-J detonation speed, (2) the time of the onset of detonation by the emission of visible light and the trajectory of pressure wave or combustion waves, and (3) the trajectory intersection with the presence of retonation wave. A nonstationary cross-correlation technique was applied to evaluate the uncertainty in estimating the run-up distance. Evaluation of the pressure wave (pressure wave speed or the pressure wave trajectory) appears to be more suitable to determine the deflagration- to-detonation run-up distance.