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Manufacture of Pyrotechnic Compositions
Published in Ajoy K. Bose, Military Pyrotechnics, 2021
Other pyrotechnic compositions like tracers, delays, caps, squibs, igniters, priming, booster, relay and fuze compositions, etc. assist in performance of the ammunition but do not exhibit special effects of the pyrotechnic ammunition. For example,Delays do not give visible special effects but provide time interval for next ignition and assist in achieving range, safety, etc.Tracers trace the path of the projectile by providing visible or infrared radiation and assist in firing the ammunition but do not provide special effects as special effects are provided by the main composition in the projectile.Initiatory compositions do not give visible special effects but are important in assisting ignition of the composition.
Influence of different blade vibration modes on fluid fluctuation in the tip vortex region: an experimental study
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2022
Jianlong Ma, Yafan Duan, Ming Zhao
The rotation speed of the blades was indirectly obtained by dividing the generator’s electrical frequency by the number of electrodes. At the beginning of the test, the frequency converter was adjusted according to the required wind speed. After the wind speed stabilized, a synchronous trigger was activated by the trigger control computer (“13” in Figure 1). The smoke generator at the inlet of the wind tunnel continuously sprayed smoke containing tracer particles. When the smoke arrived at the test section, the delay triggers (“9–12” in Figure 1) were activated. The PULSE, TR-PIV, and Norma 5000 systems began to operate synchronously. The sampling frequencies of all three sets of equipment were set to 1000 Hz, with a shooting period of 30 s.