Submicron aluminium particle size influence on detonation of dispersed fuel-oxidizer powders

• Autorzy: Tulis A.J. , Sumida W.K. , Dillon J. , Comeyne W. , Heberlein D.C.
• Języki publikacji: EN

Abstrakty

EN

A 7.32 m 152 mm I.D. horizontal detonation tube incorporating a 1.83 m long stainless steel highly-instrumented section was used to evaluate the use of submicron atomized aluminium (Al) involving the detonation of lactose-aluminium-ammonium perchlorate (CHO/Al/AP) powder mixtures dispersed in gaseous nitrogen. Piezoelectric pressure transducers and fiber-optic/photo-diode sensors spaced at 152 mm intervals provided shock- and flame-front arrival times and pressure measurements. Laser beams and video cameras assessed concentrations and homegeneity of the powder dispersions and provided calibration data for the explosive detonation initiation charges. Investigation involved powders of micro-sized CHO and 7.5-um AP, with two types of Al powders: Type 40XD flaked Al (4 m2/gS/M) and submicron Alex Al (nominal 100 nm, 500 m2/g S/M) obtained from the Argonide Corp. A pressurized vessel and appropriate nozzles dispersed candidate powders into a flowing stream of nitrogen gas. Nominal powder concentrations of 3 kg/m3 were investigated. Experiments were conducted with a constant 30 weight percent AP with variable CHO:Al ratios so that the Al varied from 7 to 35 weight percent. For comparative purpose, analytical TIGER Code Chapman-Jourget (CJ) computations were conducted. Both flaked and Alex Al powders in CHO/Al/AP powder formulations at CHO:Al ratos of 80:20, 70:30, 60:40 and 50:50 resulted in detonation characteristics that agreed well in regard to detonation velocities but were substantially lower in regard to detonation pressures when compared to analytical values. Results indicated consistent improvement in detonation velocities with Alex Al over the flaked Al, but inconsistent behaviour in detonation pressures relative to CHO:Al ratios. It is suggested that the influence of S?M is a major factor in that the two orders of magnitude greater S/M of the Alex Al over the flaked Al provides considerably greater temperature equilibration within the detonation zone. Furthermore, based on observations and a video camera, the blast outputs from the detonation tube into the atmosphere from these experiments were substantially different for the two types of Al. the flaked Al appeared to result in a fireball whereas the Alex appeared to cause an extension of detonation into the atmosphere.

• Wydawca: Komitet Termodynamiki i Spalania PAN
• Czasopismo: Archivum Combustionis
• Rocznik: 1998
• Tom: Vol. 18 nr 1-4
• Strony: 157--164
• Opis fizyczny: Bibliogr. 5 poz., rys., tab.

Twórcy

autor

Tulis A.J.

autor

Sumida W.K.

autor

Dillon J.

autor

Comeyne W.

autor

Heberlein D.C.

• IIT Research Institute, Chicago, IL, USA