Resonant Dissipation Research Articles

Two-dimensional viscous study of coupled nonlinear fluid resonances in two narrow gaps

The wave-induced hydrodynamics of coupled nonlinear piston-mode fluid resonances within two narrow gaps between three barges are numerically investigated using a two-dimensional viscous wave flume. This study aims to explore the time-dependent nonlinear interactions between fluid oscillations in the two gaps. The coupled synchronous dynamic behaviors of fluid oscillations during the transient evolution stage are first examined in terms of amplitude and frequency modulation. It is shown that phase dynamics, including phase slipping, trapping, and locking, play significant roles in establishing the coupled synchronous dynamic evolutions of fluid oscillations in the two gaps. The quasi-steady state of the amplitude- and phase-frequency responses of fluid oscillations within the gaps, along with the reflection and transmission waves in front of and behind the three-barge system, are further analyzed. This analysis clarifies the significance of viscous damping energy dissipation and radiation damping energy transfer involved in gap resonance problems. This clarification also explains the performance of fully nonlinear potential flow solvers in predicting fluid resonances in the two narrow gaps. Finally, the nonlinear dynamic features of fluid oscillations are examined. The effects of incident wave nonlinearity, i.e., wave steepness, on resonant frequencies, response amplitudes, energy dissipation, and reflection and transmission coefficients are investigated. Harmonic analysis via Fourier transformation reveals the contributions of first-, second-, and third-order harmonics to the overall response amplitudes. The physical insights gained from this study provide a deeper understanding of the coupled nonlinear dynamics of piston-mode fluid resonances in multiple narrow gaps.

Low-frequency broadband acoustic metamaterial absorber based on nested resonator and synergistic coupled weak resonances

Utilizing absorbers with sub-wavelength thickness for low-frequency broadband noise control is a challenging problem, and rapid on-demand design of structures based on target noise frequency has received continuous attention. In this work, nested cavities are introduced into the typical neck-embedded Helmholtz resonator (NEHR) to obtain the nested neck-embedded Helmholtz resonator (NNEHR), which exhibits better cavity partitioning volume fraction and covers wider sound absorption band. Both theoretical analysis and simulations demonstrate that NNEHR possesses superior acoustic properties: generating an additional absorption peak, lowering the position of the first absorption peak by 11 %, and increasing the absorption coefficient by 4.7 %. Instantaneous velocity fields and thermal-viscous energy dissipation density illustrate that the efficient sound absorption of NNEHR originates from resonant dissipation in the neck and surrounding areas. Furthermore, by combining the theoretical model with genetic algorithms, three sets of NNEHR metasurfaces are optimized. The optimized structures achieve average absorption coefficients of 0.831, 0.913, and 0.885 in the range of 250–550 Hz, 400–1000 Hz, and 500–2000 Hz, with a thickness of only 50 mm, reflecting sub-wavelength, low-frequency broadband sound absorption characteristics. The excellent absorption stems from synergistic coupled weak resonances and higher-order absorption peaks of constituent units, and the overdamping characteristic ensures the realization of the optimal structure with minimal thickness. The contribution of weak resonant units to the total sound absorption performance can be measured by the surface admittance normalized by the total incident area, and the essence of the coupling effect is the strong interaction between units with adjacent absorbing frequencies. The proposed structure exhibits good sound absorption performance and great adjustability, while the genetic algorithm optimization based on the theoretical model demonstrates high efficiency and robustness, providing a methodology for the design and on-demand optimization of low-frequency broadband structures.

Wigner Function Method for Describing Electromagnetic Field in Plasma-Like Media with Spatial Dispersion and Resonant Dissipation

The paper gives a systematic presentation of the Wigner function method (Weyl formalism) for modeling the propagation and absorption of electromagnetic waves in anisotropic and gyrotropic dissipative media with spatial dispersion. A general kinetic equation for the Wigner function (tensor) is formulated, and its asymptotic expansion up to the second order for smoothly inhomogeneous and weakly dissipative media is constructed. As a result, a modification of the method of the kinetic equation for rays is proposed, based on the stochastic description of rays, making it possible to increase the accuracy of numerical modeling of wave problems with strong transverse inhomogeneity of the absorption coefficient without increasing the amount of calculations. The technique developed can be used to describe the propagation, absorption, and scattering of electron-cyclotron waves in high-temperature plasma of magnetic traps for controlled fusion in cases where standard modeling methods do not provide the necessary accuracy.

Vibration Mitigation Using 3D-PSTMD for the Offshore Wind Turbine Considering Self-Excitation Behaviors

The self-excitation behaviors can be triggered by the blade rotation of the wind turbine. To mitigate the excessive vibration of offshore wind turbine (OWT) tower under this self-excitation addition with wind–wave loadings, a three-dimensional prestressed TMD (3D-PSTMD) is extended in this study. First, based on the Lagrange equation, the analytical formulations of 1P (rotor rotational speed) and 3P (blade passing frequency) loads from self-excitations are deduced, and more factors under real operational conditions of the OWT are further analyzed using theoretical derivation and numerical simulation. Then, structural aero-hydrodynamic loadings are modelled, and self-resonance phenomenon of the uncontrolled OWT and resonance dissipation capability of 3D-PSTMD are discussed at startup–operation–shutdown state. Finally, the energy harvesting competence of 3D-PSTMD is quantitatively calculated via the classical Wilson-[Formula: see text] algorithm under self-excitations with wind–wave loadings. Results indicate that this dashpot is remarkably able to mitigate the structural resonance responses over 61.3% and 40.5% respectively when under the 1P and 3P loadings, and it can also effectively reduce the bi-directionally horizontal vibrations of OWT under aero-hydrodynamic loadings.

Reflection of the Electromagnetic Wave from the Region of Electron Cyclotron Absorption in Thermonuclear Plasma

A new approach to the problem of the passage of the extraordinary wave through the region of the electron–cyclotron resonance in inhomogeneous plasma was considered in the framework of the full set of Maxwell’s equations, taking into account the effects of spatial dispersion and resonance dissipation. For the model one-dimensional geometry, field distributions were calculated in the vicinity of the cyclotron resonance at the second harmonic for the normal incidence of the extraordinary wave and the reflection, transmission, and absorption coefficients were found depending on the parameters of the resonance region. As a result, the fine effect of the reflection of electromagnetic radiation from the cyclotron resonance region in transparent plasma was described and the results were compared with the observations of this effect in the experiments on the microwave heating of the plasma at the L-2M stellarator.

Reflection of the Electromagnetic Wave from the Region of Electron Cyclotron Absorption in Thermonuclear Plasma

A new approach to the problem of the passage of the extraordinary wave through the region of the electron–cyclotron resonance in inhomogeneous plasma was considered in the framework of the full set of Maxwell’s equations, taking into account the effects of spatial dispersion and resonance dissipation. For the model one-dimensional geometry, field distributions were calculated in the vicinity of the cyclotron resonance at the second harmonic for the normal incidence of the extraordinary wave and the reflection, transmission, and absorption coefficients were found depending on the parameters of the resonance region. As a result, the fine effect of the reflection of electromagnetic radiation from the cyclotron resonance region in transparent plasma was described and the results were compared with the observations of this effect in the experiments on the microwave heating of the plasma at the L-2M stellarator.

Second-harmonic electron-cyclotron resonance heating: A possible impact from mode coupling near the resonance.

The short-wavelength paraxial asymptotic technique, known as Gaussian beam tracing, is extended to the case of two linearly coupled modes in plasmas with resonant dissipation. The system of amplitude evolution equations is obtained. Apart from purely academic interest, this is exactly what happens near the second-harmonic electron-cyclotron resonance if the microwave beam propagates almost perpendicularly to the magnetic field. Because of non-Hermitian mode coupling, the strongly absorbed extraordinary mode may partly transform into the weakly absorbed ordinary mode near the resonant absorption layer. If this effect is significant, it could impair the well-localized power deposition profile. The analysis of parameter dependencies gives insight into what physical factors affect the power exchange between the coupled modes. The calculations show a rather small impact of non-Hermitian mode coupling on the overall heating quality in toroidal magnetic confinement devices at electron temperatures above 200 eV.

On the computation of resonant tidal dissipation in the liquid layers of planets and stars

AbstractPlanets and stars have liquid layers that can support internal gravity waves and inertial waves respectively restored by the buoyancy and Coriolis forces. Both types of waves are excited by tides, leading to resonantly amplified dissipation. We review the theoretical formalism to compute these resonances and present some challenges and methods to overcome them.

Evaluation of Dynamic Viscosity in the 10 MHz Range Using a General-Purpose Quartz Crystal Microbalance

This study examined the validity of viscosity measurements in the frequency region of 10 MHz using a commercially available quartz crystal microbalance (QCM). Ethylene glycol aqueous solutions were used as model samples. From the changes in the resonant frequency and dissipation parameter before and after the introduction of the sample liquid, we determined dynamic viscosity through Johannsmann's equation and compared it with literature data for zero shear viscosity. As a result, the viscosity estimated by QCM was systematically higher. Based on the analysis of the electrical equivalent circuit of the resonator, we considered that such deviation is due to the energy loss inside the quartz resonator and the non-ideal nature of the interface in contact with the sample liquid. To avoid such non-idealities, we proposed a method of applying a calibration equation to the viscosity value obtained from the Johannsmann equation. This makes it possible to easily measure viscosity in the 10 MHz regions with an accuracy of ± 3 % error.

Tunable acoustic composite metasurface based porous material for broadband sound absorption

This work designs a tunable acoustic composite metasurface, with porous material and a modified microperforated panel (MPP) system. The broadband sound absorption performance of the composite metasurface is evaluated by the analytical theory, numerical simulation, and experiment in the frequency range between 200 Hz and 3500 Hz. The designed composite metasurface has a significant advantage in sound absorption performance compared with a uniform porous material, especially in the low-frequency range. The excellent sound absorption performance is achieved not only by the wavefront controlling with the phase gradient adjustment but also by the resonance dissipation of the modified MPP system. The high-order reflected waves have been converted into surface waves by the wave controlling ability of the designed metasurface for excellent sound absorption at the high frequency of interest. The modified MPP system is formed by a microperforated panel and a coiling-up space cavity to achieve excellent sound absorption in the low-frequency range. By adjusting the length of the coiling silt in the modified microperforated panel system, the absorption peak can move to the frequency of interest. The compact composite metasurface with 3 cm height has remarkably improved the sound absorption of porous material alone from low to high frequency, which could easily replace porous material for better sound absorption in industry.

Hydrodynamic performance of a new-type vertical wall breakwater with inclined culvert on a permeable rubble mound foundation

Vertical wall breakwater with inclined culvert (VWBIC) is a new-type environmentally friendly breakwater proposed in this paper, which is a further development of vertical wall breakwater with horizontal culvert (Lv and Zhao, 2021). To analyze the hydrodynamic performance of the VWBIC on a permeable rubble mound foundation and to propose the optimal structural parameters of the culvert for engineering application, an eigenfunction expansion boundary element method (EEBEM) is used. Besides, newly performed computational fluid dynamics (CFD) results are used to reveal the interaction mechanism between waves and the VWBIC. The results show that when the culvert inclined angle is positive, the VWBIC is more beneficial to engineering application. With an increase in the culvert inclined angle, the VWBIC can effectively reduce wave transmission coefficient of medium and long waves, promote the oscillatory flow of short waves and reduce the wave force on the VWBIC. Meanwhile, through the effects of wave shallowing, resonance and energy dissipation, the permeable rubble mound foundation can significantly reduce the wave reflection and wave force on the VWBIC. Finally, the optimal structural parameters of the VWBIC are obtained. All these indicate that the VWBIC is a more effective structure than vertical wall breakwater with horizontal culvert.

Shape, Resonant Frequency and Thermoelastic Dissipation Analysis of Free-Formed Microhemispherical Shells Based on Forming Process Modeling.

Free-form microhemispherical shell resonators have the advantages of high quality factor and mass production. The shape of microhemispherical shells created via this process is based on a single mold and is difficult to adjust, which affects the resonant frequency and quality factor. In this paper, a process analysis model is established through in-depth analysis of the process mechanism and flow of the free-forming method. Based on this model, the influence of the designed preforming parameters on the shape, resonant frequency and thermoelastic dissipation of the microhemispherical shell are analyzed in detail, providing theoretical guidance for parameter design. The results show that the depth and the ratio of internal to external pressure of the substrate’s annular groove affect the height and thickness of the microhemispherical shell, and the structural thickness affects the thickness of the microhemispherical shell; these in turn affect the resonant frequency and thermoelastic dissipation of the microhemispherical shell resonator. In addition, the inner diameter of the substrate’s annular groove mainly affects the radius of the support column of the microhemispherical shell, and the influence on the resonant frequency and thermoelastic dissipation of the resonator is relatively low.

The Gravitational Imprint of an Interior–Orbital Resonance in Jupiter–Io

At mid-mission perijove 17, NASA’s Juno mission has revealed a 7σ discrepancy between Jupiter’s observed high-degree tidal response and the theoretical equilibrium tidal response, namely, the Love number k 42. Here we propose an interpretation for this puzzling disagreement based on an interior–orbital resonance between internal gravity waves trapped in Jupiter’s dilute core and the orbital motion of Io. We use simple Jupiter models to calculate a fractional correction Δk 42 to the equilibrium tidal response that comes from the dynamical tidal response of a g–mode trapped in Jupiter’s dilute core. Our results suggest that an extended dilute core (r ≳ 0.7 R J) produces an interior–orbital resonance with Io that modifies Jupiter’s tidal response in Δk 42 ∼ −11%, allowing us to fit Juno’s k 42. In our proposed self-consistent scenario, Jupiter’s dilute core evolves in resonant locking with Io’s orbital migration, which allows the interior–orbital resonance to persist over geological timescales. This scenario requires a dilute core that becomes smoother or shrinks over time, together with a mode (ℓ, m, n = 4, 2, 1) with resonant tidal dissipation reaching Q 4 ∼ 1000. Jupiter’s dilute core evolution path and the dissipation mechanism for the resonant mode are uncertain and motivate future analysis. No other alternative exists so far to explain the 7σ discrepancy in Juno k 42. Our proposed interior–orbital resonance can be tested by Juno observations of k 42 tides raised on Jupiter by Europa, as obtained at the end of the extended mission (mid-2025), and by future seismological observations of Jupiter’s mode oscillation frequency.

Physically intuitive continuum mechanics model for quartz crystal microbalance: Viscoelasticity of rubbery polymers at MHz frequencies

AbstractEmploying a quartz crystal microbalance (QCM) as a MHz‐viscoelastic sensor requires extracting information from higher harmonics beyond the Sauerbrey limit, which can be problematic for rubbery polymer films that are highly dissipative because of the onset of anharmonic side bands and film resonance. Data analysis for QCM can frequently obscure the underlying physics or involve approximations that tend to break down at higher harmonics. In this study, modern computational tools are leveraged to solve a continuum physics model for the QCM's acoustic shear wave propagation through a polymer film with zero approximations, retaining the physical intuition of how the experimental signal connects to the shear modulus of the material. The resulting set of three coupled equations are solved numerically to fit experimental data for the resonance frequency Δfn and dissipation ΔΓn shifts as a function of harmonic number n, over an extended harmonic range approaching film resonance. This allows the frequency‐dependent modulus of polymer films at MHz frequencies, modeled as linear on a log–log scale, to be determined for rubbery polybutadiene (PB) and polydimethylsiloxane (PDMS) films, showing excellent agreement with time–temperature shifted rheometry data from the literature.

Stability Analysis of Power Grid Connected With Direct-Drive Wind Farm Containing Virtual Inertia Based on Integrated Dissipation Energy Model

Concerning the difficulty in unified modeling of direct-drive wind farm with virtual inertia and the unknown cause of low frequency oscillation, a detailed model of integrated dissipation energy of direct-drive wind farm is built. First, the dissipation energy model of wind generator and the integrated dissipation energy model of direct-drive wind farm containing virtual inertia and PLL is derived and built. On this basis, according to different sources of integrated dissipation energy, it is decomposed into free dissipation energy, resonant dissipation energy and forced dissipation energy. These three components respectively characterize the contribution of inherent damping, generator-grid coupled resonance and generator-grid interaction to the stability of system. And then, how the variation of wind speed and generator location affects the stability of system is analyzed quantitatively using the integrated dissipation energy. Finally, the model of IEEE 10-machine 39-bus system connected with direct-drive wind farm is built in RTDS for hardware-in-the-loop tests. Simulation results verify that, the detailed model exhibits three different oscillation states, and each generator in the wind farm contributes differently to system oscillation. The traditional equivalent model of wind farm only exhibits one oscillation state and cannot reflect the difference in contributions of generators, thus it may wrongly identify the stability of system, even aggravate oscillation.

Complexity of Fermionic Dissipative Interactions and Applications to Quantum Computing

Interactions between particles are usually a resource for quantum computing, making quantum many-body systems intractable by any known classical algorithm. In contrast, noise is typically considered as being inimical to quantum many-body correlations, ultimately leading the system to a classically tractable state. This work shows that noise represented by two-body processes, such as pair loss, plays the same role as many-body interactions and makes otherwise classically simulable systems universal for quantum computing. We analyze such processes in detail and establish a complexity transition between simulable and nonsimulable systems as a function of a tuning parameter. We determine important classes of simulable and nonsimulable two-body dissipation. Finally, we show how using resonant dissipation in cold atoms can enhance the performance of two-qubit gates.

Ultrasensitive Metasurface Biosensors by the Use of Constrained Mie Resonance and Metallic Dissipation

The figure of merit FOM <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">*</sup> is a vital evaluating indicator for optical biosensors' performance. This paper presents a metasurface in the visible regime, which has an extremely high FOM <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">*</sup> up to 304400/RIU higher than the values in many previous reports. In the broad range of the refractive index from 1.30 to 1.49, the refractive index's detection accuracy can reach 0.0001 RIU. For the adsorbed analyte's sensitivity, the biosensor achieves a high FOM <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">layer</sub> up to 91.1/nm and demonstrates excellent feasibility for the trace-amount analysis in biosensing. The high biosensing performance for an adsorbed layer with a thickness of 1 nm can show the potential in molecular layer detection. Its high biosensing performance originates from the excitation of Mie resonance in the dielectric part that can constrain the incident energy into the metal counterpart. In the previous researches, Mie resonances are generally excited in high-refractive-index dielectric nanoresonators. In this work, we find that the low-refractive-index dielectric nanoresonator can excite the Mie resonance under the existence of metal. The proposed metasurface provides a promising way to guide the design of ultrasensitive biosensors.

A Real-Time Method for Improving Stability of Monolithic Quartz Crystal Microbalance Operating under Harsh Environmental Conditions.

Monolithic quartz crystal microbalance (MQCM) has recently emerged as a very promising technology suitable for biosensing applications. These devices consist of an array of miniaturized QCM sensors integrated within the same quartz substrate capable of detecting multiple target analytes simultaneously. Their relevant benefits include high throughput, low cost per sensor unit, low sample/reagent consumption and fast sensing response. Despite the great potential of MQCM, unwanted environmental factors (e.g., temperature, humidity, vibrations, or pressure) and perturbations intrinsic to the sensor setup (e.g., mechanical stress exerted by the measurement cell or electronic noise of the characterization system) can affect sensor stability, masking the signal of interest and degrading the limit of detection (LoD). Here, we present a method based on the discrete wavelet transform (DWT) to improve the stability of the resonance frequency and dissipation signals in real time. The method takes advantage of the similarity among the noise patterns of the resonators integrated in an MQCM device to mitigate disturbing factors that impact on sensor response. Performance of the method is validated by studying the adsorption of proteins (neutravidin and biotinylated albumin) under external controlled factors (temperature and pressure/flow rate) that simulate unwanted disturbances.

Field-enhanced polarization in polytype ferric oxides: confronting anisotropy in dielectric ellipsoid dispersion

An analytic dielectric introspection in two cardinal ferric oxide polymorphs, viz. hematite and maghemite, is conducted using a three-fold line of direction. Firstly, dc field-dependent radio/audio-frequency impedance and dielectric spectra of polycrystalline MIM pellets, comprising near-stoichiometric (meticulously characterized) Fe2O3 nanoparticles, are analysed by employing the Cole–Davidson model, Jonscher’s power law and equivalent circuitry to quantify non-Debye dipolar relaxations, small polaron hopping conduction, grain core–boundary resistivity correlations and field-driven delocalization/de-trapping of carriers. Bias-tuned low-frequency enhancement of the dielectric constant by augmenting Maxwell–Wagner polarization is demonstrated for both samples, a prerequisite for conquering classical energy-storage bottleneck. Secondly, the optical dielectric function and associated parameters are evaluated under a density functional theory + U framework, to physically designate particular resonant absorption, dissipation, electronic polarization and decay. In doing so, a new crystallographically consistent and energetically stable vacancy-ordered maghemite-type supercell is constructed to accomplish reasonable computational cost. Thirdly, intrinsic anisotropy in materials sensitive to photonic excitations is videographed by simulating energy-dispersive evolution of the quadric surface to project real/imaginary dielectric tensors. The authors anticipate that this intensive technique will pictorially demonstrate anisotropic deviations in the dielectric ellipsoid, fostering materials physics over linear and nonlinear dielectrics.

An acoustic impedance structure consisting of perforated panel resonator and porous material for low-to-mid frequency sound absorption

In this paper, an acoustic impedance compound structure composed of a perforated panel resonator (PPR) and porous sound absorbing material (PSAM) is designed to improve the sound absorption for low-to-mid frequency. The PPR component is an array cell of multiple Helmholtz resonators based on perforated panel arranged in parallel. By properly introducing a PSAM component that consists of porous material layers and rigid wall into the PPR component, a matched acoustic impedance appears at the coupling of the PPR and PSAM. Thus, the designed composite structure PPR-PSAM achieves an effective wide-band sound absorption through the effect of resonance dissipation by PPR and trapped energy by PSAM. An analytical model based on acoustic-electrical analogy is established to predict the sound absorption, and a finite element model is further proposed to demonstrate the sound absorption mechanism for the PPR-PSAM. Moreover, the influences of structural parameters on the sound absorption of the PPR-PSAM are discussed, and the sound absorption of the PPR-PSAM and the MPP (micro-perforated plate), MPP-PSAM are compared. The normal sound absorption coefficient measured by impedance tube is well agreed with the predicted results. In a limited space of 80 mm, the PPR-PSAM with low perforation rate has an average sound absorption coefficient of more than 0.89 from 200–1600 Hz.