Towards probing velocity distributions in dense granular matter: Utilizing Fiber Bragg Gratings

Marlo Kunzner; Luis Henriques; Fahad Puthalath; Leonardo Facchini; Mohammadhossein Shahsavari; Léa Gommeringer; Martin Angelmahr; Peidong Yu; Matthias Sperl; Till Böhmer; Jan Philipp Gabriel

arXiv · 2512.07321

Towards probing velocity distributions in dense granular matter: Utilizing Fiber Bragg Gratings

Marlo Kunzner·Luis Henriques·Fahad Puthalath·Leonardo Facchini·Mohammadhossein Shahsavari·Léa Gommeringer·Martin Angelmahr·Peidong Yu·Matthias Sperl·Till Böhmer·Jan Philipp Gabriel

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Abstract

Granular gases are commonly characterized through their velocity distribution, which provides access to the granular temperature. In experiments, velocity distributions are typically obtained by particle tracking, which however becomes limited at moderate and high particle densities. As a way forward, we propose a new technique for measuring particle velocities in situ by using a Fiber Bragg Grating (FBG) sensor, which remains applicable at significantly higher particle densities.The FBG sensor detects strain pulses induced by particle-fiber collisions, from which the velocity of the impacting particle can be derived. Applying this method to an ensemble of granular particles allows to extract its velocity distributions as we present for a granular system excited by a vibrational shaker. We validate the extracted velocity distribution against conventional particle-tracking measurements, confirming the reliability of the FBG-based technique.

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Marlo Kunzner, Luis Henriques, Fahad Puthalath, Leonardo Facchini, Mohammadhossein Shahsavari, Léa Gommeringer, Martin Angelmahr, Peidong Yu, Matthias Sperl, Till Böhmer, Jan Philipp Gabriel. 2025-12-11. Towards probing velocity distributions in dense granular matter: Utilizing Fiber Bragg Gratings. https://arxiv.org/abs/2512.07321

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