Abstract
Soft particulate media include a wide range of systems involving athermal dissipative particles both in non-living and biological materials. Characterization of flows of particulate media is of great practical and theoretical importance. A fascinating feature of these systems is the existence of a critical rigidity transition in the dense regime dominated by highly intermittent fluctuations that severely affects the flow properties. Here, we unveil the underlying mechanisms of rare fluctuations in soft particulate flows. We find that rare fluctuations have different origins above and below the critical jamming density and become suppressed near the jamming transition. We then conjecture a time-independent local fluctuation relation, which we verify numerically, and that gives rise to an effective temperature. We discuss similarities and differences between our proposed effective temperature with the conventional kinetic temperature in the system by means of a universal scaling collapse.
Highlights
Large fluctuations are a distinguishing feature of soft particulate flows, like flows of granular media [1, 2], bubbles and foams [3], and in living matter such as biological tissues [4, 5]
In the fluid state and in the critical region this temperature agrees with an effective temperature that characterizes the probability to encounter different power injections
The proposed effective temperature is sensitive to the inherent properties of the systems, and it potentially qualifies as the effective temperature that has been searched for recently with great urgency [24, 25]
Summary
Large fluctuations are a distinguishing feature of soft particulate flows, like flows of granular media [1, 2], bubbles and foams [3], and in living matter such as biological tissues [4, 5]. Very dense systems are in a jammed state. They only move in response to a strong external force. Less packed systems are in a fluid state. They flow in response to any finite force. The flows are highly intermittent and involve rare, very large fluctuations [6] that can trigger transitions between the jammed and the fluid state [7]. Landslides [8] and avalanches [9] are transitions from a jammed to a fluid state. Clogging of hoppers [10] and breakdown of silos [11] involve the transition from a fluid to a jammed state. Predicting the frequency of appearance of such fluctuations is a question of great practical and theoretical interest
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
