An experimental study of ultrasonic vibration and the penetration of granular material

Abstract

This work investigates the potential use of direct ultrasonic vibration as an aid to penetration of granular material. Compared with non-ultrasonic penetration, required forces have been observed to reduce by an order of magnitude. Similarly, total consumed power can be reduced by up to 27%, depending on the substrate and ultrasonic amplitude used. Tests were also carried out in high-gravity conditions, displaying a trend that suggests these benefits could be leveraged in lower gravity regimes.

Ultrasonic Auger for Narrow-Gauge Borehole Drilling

“…Glass micro-spheres were chosen due to their wellcharacterised properties and uniform spherical shape. The particle size distribution ranged from 150 µm to 250 µm to closely match the distribution of fine-sand [4] used for similar ultrasonics and granular material experiments [2].…”

“…Previous work investigating ultrasonic vibration and granular material utilised the longitudinal mode for a simple penetrator, and showed a large decrease in both total consumed power as well as required overhead force [2]. Continuing this work, the longitudinal mode was also chosen for use with this auger.…”

“…The BADGER device solves this issue by using inflatable air clamps to grip the borehole. As part of a plan to miniaturise the BADGER device for use in narrow-gauge drilling, integration of ultrasonic vibration to the drill head has been considered, due to its force reduction properties [2]. A reduction in the WOB and torque requirements will allow a smaller device to have more manoeuvrability, with less overall mass and complexity of supporting architecture.…”

Ultrasonically Assisted Hammer-Action Penetrators in Planetary Regolith

“…Parallel to this, ultrasonic vibration has been shown to reduce overhead force requirements under progression through granular material (Firstbrook et al 2017).…”

Some Challenges in Gravity Related Research

“…Hypergravity created by centrifuges or by strong magnetic fields can be very illustrative of gravity and how it has an impact on the systems of study. One could use the hypergravity data to build a model and use it to extrapolate values below one g based on the gravity continuum principle, see (e.g., Firstbrook et al, 2017). One could also make use of centrifuges to simulated microgravity or lower gravity by means of the Reduced Gravity Paradigm (Van Loon, 2016).…”