Related Experiment Video
Updated: Sep 30, 2025
09:23
Reactive Inkjet Printing and Propulsion Analysis of Silk-based Self-propelled Micro-stirrers
Published on: April 26, 2019
7.9K
Memory effects in spiral diffusion of rotary self-propellers
Parvin Bayati1,2, Amir Nourhani1,3,4
1Department of Mechanical Engineering, University of Akron, Akron, Ohio 44325, USA.
Physical Review. E
|March 16, 2022
Summary
Self-propelled particle motion, combining rotation and diffusion, creates spiral paths. This study analyzes spiral diffusion under realistic noise conditions, revealing diverse dynamic behaviors based on key physical parameters.
Area of Science:
- Physics
- Statistical Mechanics
- Soft Matter
Background:
- Self-propelled particles exhibit complex trajectories due to coupled rotational and translational motion.
- Previous work analyzed spiral diffusion in the white-noise limit.
Purpose of the Study:
- To extend spiral diffusion analysis to more realistic noise models.
- To investigate the impact of Gaussian memory and Ornstein-Uhlenbeck processes on self-propeller dynamics.
Main Methods:
- Mathematical modeling of self-propeller motion.
- Analysis of stochastic processes with Gaussian memory.
- Incorporation of Ornstein-Uhlenbeck processes for orientational fluctuations.
Main Results:
- The coupling of deterministic rotation and stochastic diffusion results in spiral trajectories.
- A variety of dynamical regimes are observed, including crossovers in angular dynamics.
- These regimes are dependent on inertial timescale, orientational diffusivity, and angular speed.
Conclusions:
- The study provides a more realistic framework for understanding spiral diffusion.
- The findings highlight the influence of noise characteristics on particle dynamics.
- This work contributes to the understanding of active matter systems.
Related Concept Videos
01:10Residual Stresses in Circular Shafts
273
In materials that exhibit elastic and plastic behavior, known as elastoplastic materials, residual stresses can accumulate when these materials experience plastic deformation. This deformation arises from either high levels of shearing stress or significant strains. Residual stresses are internal stresses that persist within a material after removing the external force causing deformation. This phenomenon is demonstrated when observing the behavior of a shaft under torque; notably, the...
273
01:20Plastic Deformation in Circular Shafts
262
When materials are subjected to forces that surpass their yield strength, they undergo a process known as plastic deformation. This results in a permanent alteration or strain in their structure. This concept can be specifically applied to circular shafts, where the deformation leads to a change in its shape. The precise evaluation of this plastic deformation requires understanding the stress distribution within the circular shaft, which is achieved by calculating the maximum shearing stress in...
262
01:30Typical Model Studies
454
Fluid mechanics model studies often utilize scaled-down systems to predict fluid behavior in full-scale environments, such as river flows, dam spillways, and structures interacting with open surfaces. Maintaining Froude number similarity in river models is crucial, as it replicates surface flow features like wave patterns and velocities.
454
01:15Thin-Walled Hollow Shafts
277
In analyzing a thin-walled hollow shaft subjected to torsional loading, a segment with width dx is isolated for examination. Despite its equilibrium state, this segment faces torsional shearing forces at its ends. These forces are quantitatively described by the product of the longitudinal shearing stress on the segment's minor surface and the area of this surface, leading to the concept of shear flow. This shear flow is consistent throughout the structure, indicating a uniform distribution...
277
01:10Deformation in a Circular Shaft
481
One of the distinctive characteristics of circular shafts is their ability to maintain their cross-sectional integrity under torsion. In other words, each cross-section continues to exist as a flat, unaltered entity, simply rotating like a solid, rigid slab. To understand the distribution of shearing stress within such a shaft, consider a cylindrical section inside this circular shaft. This section has a length of L and a radius of R, with one end fixed. The radius of the cylindrical section is...
481
01:18Stress Concentrations in Circular Shafts
280
Consider the elastic torsion formula, which applies to a circular shaft with a consistent cross-section. This formula assumes that the shaft's ends are loaded with rigid plates firmly attached. However, in many cases, torques are applied to the shaft through mechanisms like flange couplings or gears, which are connected by keys inserted into keyways. This application method modifies the stress distribution near the point of torque application, causing it to deviate from the distributions...
280