Flow in a pressurized, vapor condensation boron nitride nanotube production rig is modeled. A laser provides a thermal energy source to the tip of a boron fiber bundle in a high-pressure nitrogen chamber causing a plume of boron-rich gas to rise. The buoyancy-driven flow is modeled as a mixture of thermally perfect gases (B, , N, , BN) in either thermochemical equilibrium or chemical nonequilibrium, assuming steady-state melt and vaporization from a 1 mm radius spot at the axis of an axisymmetric chamber. The simulation is intended to define the macroscopic thermochemical environment from which boron-rich species, including nanotubes, condense out of the plume. Simulations indicate a high-temperature environment () for elevated pressures within 1 mm of the surface, sufficient to dissociate molecular nitrogen and form BN at the base of the plume. Modifications to the program LAURA, a finite volume-based solver for hypersonic flows including coupled radiation and ablation, are described to enable this simulation. High-pressure synthesis conditions enable formation of BN vapor in the plume, which may serve to enhance formation of exceptionally long nanotubes in the pressurized vapor condensation process.
Laser Vaporization and Plume Chemistry in a Boron Nitride Nanotube Production Rig
Journal of Thermophysics and Heat Transfer ; 27 , 3 ; 369-381
2013-05-28
13 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
Study of the Boron Nitride Laser Ablated Plasma Plume with Nanosecond and Femtosecond Pulses
British Library Conference Proceedings | 2001
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