A tri-stable energy harvester in rotational motion: Modeling, theoretical analyses and experiments

Limited by the structure, the high-efficiency vibration energy harvesting and vibration suppression have always been a theoretical bottleneck and technical challenge in this field. The nonlinear design of the new vibration structure is an indispensable link in the development of vibration energy harvesting and vibration suppression technologies. Nonlinear technologies not only have the potential to improve the efficiency of the energy harvesters by increasing the useful frequency bandwidth and output power but also have the potential to improve the efficiency of vibration suppressors by reducing the transmission rate and transfer energy. Nonlinear vibration energy harvesting and vibration suppression technologies have been salient topics in the literature and have attracted widespread attention from researchers. The present work provides a comprehensive review on the recent advances in nonlinear vibration energy harvesting and vibration suppression technologies. In particular, the latest developments in multifunctional hybrid technologies are proposed. Various key aspects to improve the performance of nonlinear vibration energy harvesting and vibration suppression systems are discussed, including implementations and configuration designs, nonlinear dynamics mechanisms, various optimizations, multifunctional hybrid, application prospects, and future outlooks.

Nonlinear vibration energy harvesting and vibration suppression technologies: Designs, analysis, and applications

In this paper, by using a stochastic reaction-diffusion-taxis model, we analyze the picophytoplankton dynamics in the basin of the Mediterranean Sea, characterized by poorly mixed waters. The model includes intraspecific competition of picophytoplankton for light and nutrients. The multiplicative noise sources present in the model account for random fluctuations of environmental variables. Phytoplankton distributions obtained from the model show a good agreement with experimental data sampled in two different sites of the Sicily Channel. The results could be extended to analyze data collected in different sites of the Mediterranean Sea and to devise predictive models for phytoplankton dynamics in oligotrophic waters.

Spatio-temporal behaviour of the deep chlorophyll maximum in Mediterranean Sea: Development of a stochastic model for picophytoplankton dynamics

Dynamics and energy generation of a hybrid energy harvester under colored noise excitations

Bifurcations in a fractional birhythmic biological system with time delay

This work presents a general class of prototype birhythmic dynamical systems, which can be extensively used to study the generation of complex bifurcation of limit cycles. Using a delay nonlinear Langevin approach, the stationary probability distribution and the escape problem are investigated under the influences of noise and time delay feedback. We discuss a new mechanism for the translocation of the amplitude in which the energy originates from noise. The results indicate that depending on the parameter space the system exhibits a transition from birhythmic to monorhythmic behavior or amplitude death. Besides, results demonstrated that time delay and feedback intensity as well as noise intensity will induce the appearance of stochastic bifurcation. Moreover, a novel finding is that the mean first passage time non-monotonically depends on the noise intensity and the dominant frequency of the oscillation. This finding represents the evidence of the noise-enhanced stability and stochastic resonant activation in the prototype dynamical system, whose occurrence is maintained for different values of the delay feedback intensity.

Noise-induced phenomena in a versatile class of prototype dynamical system with time delay

The performances of an energy harvester are usually limited. To improve these, the time-delayed feedback control is used in a novel nonlinear hybrid energy harvester for different types of external excitation. Based on the generalized harmonic transformation, the equivalent uncoupled equation, the vibration response, the harvested power and stochastic resonance of the hybrid energy harvester with time-delayed control are analyzed to obtain the standards for appropriate values of different control parameters. The response under harmonic excitation exhibits that time-delayed feedback control technique can stabilize unstable periodic orbits of the attractor to enhance the output power of electromechanical systems. For harmonic excitation or stochastic excitation, the value of the averaging harvested power of the system without time-delayed feedback control is lower than that of the control system, which plays a great realistic significance in the choose of the control parameters for improving the performance of the hybrid energy harvester. In case of combined harmonic and stochastic excitations, the time-delayed feedback control also can enhance stochastic resonance phenomenon, which can lead to a large response and give out a high output power.

Tao Yang

Papers

Noise-induced phenomena in a versatile class of prototype dynamical system with time delay

Time delay improves beneficial performance of a novel hybrid energy harvester