Mi-An Xue

Numerical Simulation of Sloshing Phenomena in Cubic Tank with Multiple Baffles

A two-phase fluid flow model solving Navier-Stokes equations was employed in this paper to investigate liquid sloshing phenomena in cubic tank with horizontal baffle, perforated vertical baffle, and their combinatorial configurations under the harmonic motion excitation. Laboratory experiment of liquid sloshing in cubic tank with perforated vertical baffle was carried out to validate the present numerical model. Fairly good agreements were obtained from the comparisons between the present numerical results and the present experimental data, available numerical data. Liquid sloshing in cubic tank with multiple baffles was investigated numerically in detail under different external excitation frequencies. Power spectrum of the time series of free surface elevation was presented with the aid of fast Fourier transform technique. The dynamic impact pressures acting on the normal and parallel sidewalls were discussed in detail.

Shock-induced fast reactions of zinc nanoparticles and RDX

Fast reactions of zinc nanoparticles and RDX were investigated in normal incident shock waves. The emergence time and emission spectra intensity of partial products such as NO2, H, C2, O, CO, CH2O, CO2, H2O and ZnO were observed by a TDS5054 oscilloscope. The results indicate that NO2 appears first in each experiment, which is in agreement with the theoretical results. The addition of zinc nanoparticles to RDX can not only shorten the ignition delay time by 20% but also double the shockwave diffusion velocity to 2180 ± 50 m s−1 and triple the temperature to 2020 ± 60 K. The emergence time of products shortens by around 10–40% and the emission spectra intensity of H2O and CH2O rises by about three times and one times, respectively. CO2, H2O and O2 in various concentrations were introduced into the zinc–RDX reaction, respectively, which indicate that O2 made the ignition delay time shorten by over 30%, the effect of H2O was not prominent while CO2 made the ignition delay time lag by around 30%. The results indicate that the Zn–O2 reaction mainly occurs in O2, CO2 and H2O.

Effects of copper micro-particles on the detonation characteristics of RDX powder

The effects of copper micro-particles on the detonation characteristics of RDX powder were investigated in a horizontal shock tube with internal dimensions of 100 mm diameter and 4 m length using an instantaneous spectrum detection apparatus. The emergence time and emission spectral intensity of the main products such as NO2, H, C2, O, CO, CH2O, CO2 and H2O were observed by a TDS5054 oscilloscope. With or without the addition of copper micro-particles into RDX, NO2 appears first in every experiment, which is in agreement with theoretical results. However, the addition of copper micro-particles to RDX can shorten the emergence time by 7–18%; it can also increase the peak blast pressure by about 133%. In addition, O2, H2O and CH2O in various quantities were introduced into this experiment, respectively, which indicate that O2 can obviously affect the results that may shorten the emergence time of NO2 by 31% and increase the peak blast pressure by 167%.