Explosively driven hierarchical particle jetting

Numerical Simulation of an Explosively Driven HVDC Circuit Breaker

High Voltage Direct Current (HVDC) circuit breakers have to suppress high values of currents at high voltages in absence of current-zero points. This makes the arc interruption more severe than the case of conventional AC networks. For circuit breaking in HVDC networks, a capacitor-inductor set has been inserted in parallel with the circuit breaker to inject reverse current to the interruption ...

Surface oscillation and jetting from surface attached acoustic driven bubbles.

We report on an experimental study of the onset of surface oscillation and jetting of bubbles attached to a rigid surface. The driving frequency is 16.27 kHz and the radius of the spherical capped bubble is 160 ± 5 μm. The acoustic amplitude is increased from 0 to 0.085 bar while the oscillation is recorded with a high-speed camera at 180,000 frames/s over 8100 periods of oscillations. The radi...

Selective spreading and jetting of electrically driven dielectric films.

We study the electrically driven spreading of dielectric liquid films in wedge-shaped gaps across which a potential difference is applied. Our experiments are in a little-studied regime where, throughout the dynamics, the electrical relaxation time is long compared to the time for charge to be convected by the fluid motion. We observe that at a critical normal electric field the hump-shaped lea...

An empirical model for the ignition of explosively dispersed aluminum particle clouds

An empirical model for the ignition of aluminum particle clouds is developed and applied to the study of particle ignition and combustion behavior resulting from explosive blast waves. This model incorporates both particle ignition time delay as well as cloud concentration effects on ignition. The total mass of aluminum that burns is found to depend on the model, with shorter ignition delay tim...

Considerations for Explosively Driven Conical Shock Tube Design: Computations and Experiments