CN-122021413-A - Random response analysis of wake flow type hybrid energy collector under pulsating wind excitation

CN122021413ACN 122021413 ACN122021413 ACN 122021413ACN-122021413-A

Abstract

The invention relates to random response analysis of a wake flow type hybrid energy collector under pulsating wind excitation, which comprises the steps of establishing an equivalent electromechanical coupling dynamics model based on a simplified model of 'setting a static upstream blunt body in front of a main blunt body and exciting vibration by utilizing periodic vortex shedding wake flow force', introducing random phases into wake flow vibration excitation to represent random fluctuation of wake flow force under the pulsating wind, deducing an amplitude-phase slow-change modulation equation set and a first-order asymptotic analysis response expression of displacement, voltage and current by adopting a multi-scale method after carrying out dimensionality and parameter scale recalibration on the model, linearizing the slow-change equation under steady-state conditions, combining a moment method and an Earthway differential rule to obtain second-order statistics of amplitude and phase, determining steady moment and average output power of output voltage and output current according to the second-order statistics, and realizing rapid evaluation and parameter design support on the output performance of the wake flow type hybrid energy collector under the random excitation.

Inventors

ZHANG YING
Qin Ruobing
ZHENG KAIXIN
ZHANG JINGWEN
QIN QIANQIAN

Assignees

西北工业大学

Dates

Publication Date: 20260512
Application Date: 20260109

Claims (9)

1. A random response analysis of a wake-flow hybrid energy harvester under pulsating wind excitation, the method comprising: establishing a dimensionless electromechanical coupling dynamics model based on a dynamic balance relation, a charge conservation relation and an electromagnetic induction relation of a main blunt body in the target wake-flow type piezoelectric-electromagnetic hybrid energy collector, wherein the dimensionless electromechanical coupling dynamics model takes wake-flow induced vibration force as an external excitation item, and a static upstream blunt body is arranged in front of the main blunt body of the target wake-flow type piezoelectric-electromagnetic hybrid energy collector; carrying out multi-scale perturbation expansion on the dimensionless electromechanical coupling dynamics model by combining a multi-scale method, a fast time scale, a slow time scale and a partial derivative operator to obtain a first-order approximation equation set and a second-order approximation equation set of the dimensionless electromechanical coupling dynamics model; Determining an amplitude-phase slow-change modulation equation set of a dimensionless electromechanical coupling dynamics model and a first-order asymptotic random response result according to the first-order approximation equation set, the second-order approximation equation set and tuning parameters, wherein the first-order asymptotic random response result comprises a first-order asymptotic analytical formula of voltage and a first-order asymptotic analytical formula of current; based on steady-state conditions, solving an amplitude-phase slow-change modulation equation set by adopting a linearization method, a moment method and an Earthway differential rule, and determining an amplitude second-order statistic of a dimensionless electromechanical coupling dynamics model; And determining a target random response result of the target wake-flow type piezoelectric-electromagnetic hybrid energy collector according to the amplitude second-order statistic and the first-order asymptotic random response result, wherein the target random response result comprises a second-order steady-state moment of output voltage, a second-order steady-state moment of output current and average output power.
2. The method of claim 1, wherein constructing a dimensionless electromechanical coupling dynamics model based on a primary blunt body dynamics balance relationship, a charge conservation relationship, and an electromagnetic induction relationship in the target wake-type piezoelectric-electromagnetic hybrid energy harvester comprises: Determining an equivalent mechanical vibration equation according to the dynamic balance relation of the main blunt body under the action of wake induced vibration force; Determining a piezoelectric circuit equation of a piezoelectric transduction branch based on a charge conservation relationship between a piezoelectric capacitor and a load loop in a target wake-up piezoelectric-electromagnetic hybrid energy collector; Determining an electromagnetic circuit equation of an electromagnetic transduction branch based on an electromagnetic induction relation between coil inductance and loop resistance of a target wake-up piezoelectric-electromagnetic hybrid energy collector; Establishing an initial electromechanical coupling dynamics model by combining an equivalent mechanical vibration equation, a piezoelectric circuit equation and an electromagnetic circuit equation; And carrying out dimensionless treatment on the initial electromechanical coupling dynamics model to obtain the dimensionless electromechanical coupling dynamics model.
3. The method of claim 1, wherein the combining the multiscale method, the fast time scale, the slow time scale, and the partial derivative operator performs multiscale perturbation expansion on the dimensionless electromechanical coupling dynamics model to obtain a first-order approximation equation set and a second-order approximation equation set of the dimensionless electromechanical coupling dynamics model, comprising: Based on the periodic vortex shedding characteristic of wake induced vibration force and the random fluctuation characteristic of fluid speed, converting an external excitation term in the dimensionless electromechanical coupling dynamics model into a random fluctuation excitation term; according to preset parameters, carrying out scale recalibration on damping items, nonlinear stiffness items, electromechanical coupling items and random fluctuation excitation items in the dimensionless electromechanical coupling dynamics model to obtain a remarked dimensionless electromechanical coupling dynamics model; Constructing a multi-scale perturbation unfolding solution of the remarked dimensionless electromechanical coupling dynamics model based on the fast time scale and the slow time scale; determining a derivative operator based on the fast time scale and the slow time scale; and carrying out multi-scale perturbation expansion in the dimensionless electromechanical coupling dynamics model after the recalibration according to the multi-scale perturbation expansion solution and the derivative operator, and sorting the expansion result according to the homogeneous order of preset parameters to obtain a first-order approximation equation set and a second-order approximation equation set of the dimensionless electromechanical coupling dynamics model.
4. A method according to claim 3, wherein the transforming the external excitation term in the dimensionless electromechanical coupling dynamics model into a random fluctuation excitation term based on the periodic vortex shedding feature of wake induced vibration forces and the random fluctuation characteristic of fluid velocity comprises: Transforming an external excitation term acting on the main blunt body into periodic excitation based on the characteristic of periodic vortex shedding wake generated by the static upstream blunt body under the action of fluid; and adding a noise item and an excitation intensity parameter to the phase item of the periodic excitation based on the random fluctuation characteristic of the fluid speed to obtain a random fluctuation excitation item.
5. A method according to claim 3, wherein said determining the amplitude-phase slow-change modulation equation set and the first-order asymptotic random response result of the dimensionless electromechanical coupling dynamics model from the first-order approximation equation set, the second-order approximation equation set, and the tuning parameters comprises: Solving a first order approximation equation set to obtain a complex amplitude general solution of the first order approximation equation set, and a proportional relation between voltage complex amplitude and current complex amplitude in the complex amplitude general solution of the first order approximation equation set and displacement complex amplitude respectively, wherein the complex amplitude general solution of the first order approximation equation set comprises a complex amplitude general solution of dimensionless displacement, a complex amplitude general solution of voltage and a complex amplitude general solution of current; substituting the complex amplitude general solution and the proportional relation of the first-order approximation equation set into the second-order approximation equation set, and eliminating the perpetual terms to obtain the solvability condition of the displacement complex amplitude; Determining a detuning relation between the fluctuation frequency in the random fluctuation excitation item and the natural frequency of the system based on the tuning parameter, substituting the tuning parameter into a solvability condition, and determining a slow-variation evolution equation of the displacement complex amplitude; separating the real part and the imaginary part of the slow-change evolution equation according to the polar coordinate analysis of the complex amplitude to obtain an amplitude-phase slow-change modulation equation set; Based on the complex amplitude general solutions of the amplitude-phase slow-change modulation equation set and the first-order approximation equation set and the proportional relation between the voltage complex amplitude and the current complex amplitude in the complex amplitude general solutions of the first-order approximation equation set and the displacement complex amplitude, respectively, converting the displacement, the voltage and the current in the dimensionless electromechanical coupling dynamics model after recalibration into a form of combining fast oscillation and slow change envelop, and obtaining a first-order asymptotic analytical formula of the corresponding main blunt body displacement, a first-order asymptotic analytical formula of the voltage and a first-order asymptotic analytical formula of the current.
6. The method of claim 1, wherein the solving the system of amplitude-phase slow-change modulation equations based on steady-state conditions using a linearization method, a moment method, and an eatstone differential rule to determine the amplitude second order statistic and the phase second order statistic of the dimensionless electromechanical coupling dynamics model comprises: determining the random excitation intensity parameter as zero, and acquiring a steady-state equation set and a steady-state working point of an amplitude-phase slow-change modulation equation set by combining steady-state conditions; based on a steady-state equation set, a steady-state working point and a disturbance decomposition analysis type, linearizing an amplitude-phase slow-change modulation equation set to construct a linearization random differential equation set of an amplitude disturbance term and a phase disturbance term; Performing moment operation on the linearized random differential equation set by using a moment method and an Earthway differential rule to determine a disturbance second-order statistic equation set, wherein the disturbance second-order statistic equation set comprises a second-order statistic equation of an amplitude disturbance term, a second-order statistic equation of a phase disturbance term and a second-order statistic equation of an amplitude-phase cross disturbance term; And respectively solving a disturbance second order statistic equation set by using the Kramer rule to obtain an amplitude second order statistic.
7. The method of claim 1, wherein determining the target random response result of the target wake-type piezoelectric-electromagnetic hybrid energy harvester based on the amplitude second order statistic and the first order asymptotic random response result comprises: extracting a voltage envelope magnitude based on a first-order asymptotic resolution of the voltage, and extracting a current envelope magnitude based on a first-order asymptotic resolution of the current; combining the amplitude second order statistic with the voltage envelope amplitude to determine the second order steady-state moment of the output voltage; combining the amplitude second order statistic with the current envelope amplitude to determine the second order steady-state moment of the output current; and carrying out weighted proportion on the second-order steady-state moment of the output voltage and the second-order steady-state moment of the output current according to the piezoelectric transduction branch power weight coefficient and the electromagnetic transduction branch power weight coefficient, and determining the average output power.
8. A computer readable storage medium, characterized in that the computer readable storage medium comprises a stored executable program, wherein the executable program when run controls a device in which the storage medium is located to perform the method of any one of claims 1 to 7.
9. A computer program product comprising a computer program which, when executed by a processor, implements the method according to any one of claims 1 to 7.

Description

Random response analysis of wake flow type hybrid energy collector under pulsating wind excitation Technical Field The invention relates to the technical field of response analysis of hybrid energy collectors, in particular to random response analysis of a wake-flow hybrid energy collector under pulsating wind excitation. Background Along with the improvement of the environment-friendly, low-carbon and long-endurance operation requirements in the aerospace field, the aircraft faces higher requirements on the aspects of endurance, maintenance convenience and safety, and the limitations of the traditional battery on the aspects of difficult energy supplementing in remote environments, low residual electric quantity recovery efficiency, thermal runaway and other safety risks are gradually highlighted, so that the engineering requirements of 'autonomous and sustainable energy supply' are difficult to fully meet. Accordingly, energy harvesting techniques are proposed for capturing and converting energy from the aircraft surroundings (e.g., light, heat, vibration, airflow) to provide auxiliary or self-powered power sources. In the existing energy collection technology, the flow induced vibration energy collector can directly utilize airflow kinetic energy to induce structural vibration, and converts mechanical energy into electric energy through mechanisms such as piezoelectricity and electromagnetism, so that the piezoelectric-electromagnetic hybrid energy collector formed by further fusion can improve energy capture density and output capacity under the condition that volume increase is not obvious. Wake-induced vibration is a type of common flow-induced vibration that generates vibrations as a fluid passes over a bluff body, creating a wake at its tail, and the pressure generated by these wake causes the tail structure to be periodically subjected to alternating airflow pressures. However, the following technical problems still remain in the current research on wake-type hybrid energy collectors: 1) The working condition randomness is considered to be insufficient, namely uncertain factors such as flow speed pulsation, flow direction time variation and the like commonly exist in an actual fluid environment, but the current research is still mainly based on deterministic dynamic analysis under a stable working condition of a laboratory, and the random disturbance influence of the actual working condition is difficult to accurately obtain. 2) The random characteristic of wake excitation leads to complex response, namely, in practical application, wake force tends to show random fluctuation, a nonlinear structure of a system is overlapped again, electromagnetic energy collection can be influenced by mechanical impact, coulomb friction, harmonic excitation, gaussian white noise and other complex external excitation, so that dynamic response and output are more complex, and reliable evaluation of output voltage, current and power is influenced. 3) The analysis characterization means facing statistics is lacking, namely engineering design focuses more on steady-state statistical characteristics (such as mean value, mean square value/variance, average power and the like) of output, but under the condition of coexistence of random excitation and electromechanical coupling, amplitude, voltage/current statistical moment and average output power cannot be directly obtained from a model, so that parameter design and performance evaluation often depend on a large number of numerical simulations. It should be noted that the information disclosed in the above background section is only for enhancing understanding of the background of the invention and thus may include information that does not form the prior art that is already known to those of ordinary skill in the art. Disclosure of Invention The invention provides random response analysis of a wake-flow type hybrid energy collector under pulsating wind excitation, a computer readable storage medium and a computer program product, which can effectively overcome the defects in the prior art. Other features and advantages of the invention will be apparent from the following detailed description, or may be learned by the practice of the invention. According to a first aspect of the present invention there is provided a random response analysis of a wake-type hybrid energy harvester under pulsating wind excitation, the method comprising: establishing a dimensionless electromechanical coupling dynamics model based on a dynamic balance relation, a charge conservation relation and an electromagnetic induction relation of a main blunt body in the target wake-flow type piezoelectric-electromagnetic hybrid energy collector, wherein the dimensionless electromechanical coupling dynamics model takes wake-flow induced vibration force as an external excitation item, and a static upstream blunt body is arranged in front of the main blunt body of the target wake-flow type piezoelectric-el