Nonlinear Dissipation Research Articles

Nonlinear energy dissipation and transfers in coarsening systems.

During coarsening, small structures disappear, leaving behind only large ones. Here we study the spectral energy transfers in Model A, where the order parameter ϕ evolves via nonconserved dynamics. We show that the nonlinear interactions dissipate fluctuations and facilitate energy transfers among the Fourier modes so that only ϕ(k=0), where k is the wave number, survives at the end and approaches the asymptotic value +1 or -1. We contrast the coarsening evolution for the initial conditions with 〈ϕ(x,t=0)〉=0 and with uniformly positive or negative ϕ(x,t=0).

Influence of Amplitude-Modulated Force and Nonlinear Dissipation on Chaotic Motions in a Parametrically Excited Hybrid Rayleigh–Van der Pol–Duffing Oscillator

The generation and evolution of chaotic motions in a hybrid Rayleigh–Van der Pol–Duffing oscillator driven by parametric and amplitude-modulated excitation forces are investigated analytically and numerically. By using the Melnikov method, the conditions for the appearance of horseshoe chaos in our system are derived in the case where the modulation frequency [Formula: see text] and the forcing frequency [Formula: see text] are the same [Formula: see text]. The obtained results show that the chaotic region decreases and increases in certain ranges of frequency. The numerical simulations based on the basin of attraction of initial conditions validate the obtained analytical predictions. It is also found that in the case where [Formula: see text] is irrational, the increase of amplitude-modulated force accentuates the fractality of the basin of attraction. The global dynamical changes of our model are numerically examined. It is found that our model displays a rich variety of bifurcation phenomena and remarkable routes to chaos. In addition, the presence of the hybrid Rayleigh–Van der Pol damping force reduces the chaotic domain in the absence of amplitude-modulated force. But when the amplitude-modulated force acts on the system, the chaotic oscillations decrease and disappear. Further, the geometric shape of the chaotic attractors considerably decreases in the presence of the amplitude-modulated excitation force. On the other hand, the system presents transient chaos, torus-chaos and torus of different topologies when [Formula: see text] is irrational.

Simultaneous features of ternary hybrid nanoparticles on thermal radiative flow configured by Darcy–Forchheimer porous surface

Due to its remarkable thermodynamic development in various engineering sciences, the dispersion of nanostructures in classical base liquids is receiving greater attention from researchers and scientists. In light of the aforementioned inspirations, the suggested research is associated with using a water-based ternary-hybrid nanofluid that contains three unique nanostructures, silicon dioxide, titanium dioxide and aluminum oxide to optimize the heating process in science and engineering. In this situation, the influence of a chemically reactive magneto-hydrodynamics (MHD) Darcy–Forchheimer ternary hybrid composites transport involving nonlinear radiation across an exponentially permeable stretched surface is highlighted with the model’s physical initial and boundary constraints. The simulation of the heat expression also includes the impacts of nonlinear thermal radiations, energy supply, energy dissipation and magnetic force. Furthermore, the interpretation of Buongiorno’s theory involves spontaneous and thermophoresis diffusions. Entropy analysis is explained using the second law of thermodynamics. We converted the model framework for fluid movement, energy and mass transfer (together with ternary hybrid nanofluid characteristics) into self-similar nondimensional differential equations, that were then further analytically evaluated by using the homotopy asymptotic method (HAM) technique via Mathematica software. The acquired results are illustrated numerically and graphically to study the behavior of fluid flow, heat, concentration distribution, drag force, rate of heat and mass transfer for various emergent components to gain scientific comprehension. With the growing values of magnetic, porosity and Forchheimer number, the nature of the velocity profile goes down.

Unconditionally Stable Numerical Scheme for Heat Transfer of Mixed Convective Darcy–Forchheimer Flow of Micropolar Fluid Over Oscillatory Moving Sheet

AbstractThis contribution proposes a third-order numerical scheme for solving time-dependent partial differential equations (PDEs). This third-order scheme is further modified, and the new scheme is obtained with second-order accuracy in time and is unconditionally stable. The unconditional stability of the new scheme is proved by employing von Neumann stability analysis. For spatial discretization, a compact fourth-order accurate scheme is adopted. Moreover, a mathematical model for heat transfer of Darcy–Forchheimer flow of micropolar fluid is modified with an oscillatory sheet, nonlinear mixed convection, thermal radiation, and viscous dissipation. Later on, the dimensionless model is solved by the proposed second-order scheme. The results show that velocity and angular velocity have dual behaviors by incrementing coupling parameters. The proposed second-order accurate in-time scheme is compared with an existing Crank–Nicolson scheme and backward in-time and central in space (BTCS) scheme. The proposed scheme is shown to have faster convergence than the existing Crank–Nicolson scheme with the same order of accuracy in time and space. Also, the proposed scheme produces better order of convergence than an existing Crank–Nicolson scheme.

A novel model of non-linear radiative Williamson nanofluid flow along a vertical wavy cone in the presence of gyrotactic microorganisms

ABSTRACT A novel mathematical technique for an unsteady bioconvective flow of Williamson nanofluids over a vertical wavy cone in the presence of non-linear radiation and viscous dissipation impacts is investigated. The cone surface is described by a sinusoidal function while the components of the extra stress tensor are presented in terms of the dynamic viscosity. The irregular wavy surface is referred to the convective boundary conditions and nanoparticle passively controls conditions. The governing equations are presented in general forms then the condition and suitable transformations are used to map the wavy cone to regular domain. A fully implicit finite differences method (FDM) is applied to solve the converted system and wide ranges of independent variables are assumed. . The major outcomes disclosed that the increase in the Williamson number causes a reduction the nanofluid flow while the skin friction coefficient is rising. Further, there is an enhancement in the values of the Nusselt number up to 75% is obtained as Biot number is altered from 0.1 to 0.4. Also, the convective boundary conditions in presence of the non-linear radiations are recommended to enhance the velocity, temperature and rate of the heat transfer.

Impacts of entropy generation in radiative peristaltic flow of variable viscosity nanomaterial

Current analysis highlights the aspects of different nanoparticles in peristalsis with entropy generation. Mathematical equations of considered problem are modelled via conservation laws for mass, momentum and energy. Such equations contain variable viscosity, nonlinear thermal radiation, viscous dissipation, heat generation/absorption and mixed convection aspects. Boundary conditions comprise the second order velocity and first order thermal slip effects. Entropy expression is obtained by utilization thermodynamics. Simplified and dimensionless forms of the considered conservative laws are obtained through lubrication technique. Resulting system of equations subject to the considered boundary conditions is solved numerically via built-in shooting procedure in Mathematica. Such numerical procedure is very suitable to obtain numerical results directly and fastly in the form of graphs. Further all the considered flow quantities are discussed graphically for the significant parameters of interest in detail. Both velocity and temperature are decreasing against large volume fraction parameter. Increasing temperature dependent viscosity effects decrease the entropy and enhance the Bejan number.

A new approach to atmospheric turbulence measurements using HOSE on radar backscattered echoes

A Novel approach has been proposed for the measurement of turbulent energy dissipation rate (ε) from Nonlinear index (NLI) based measurements using the Higher Order Spectral Estimation (HOSE) technique. The higher order spectral analysis, also known as Bispectrum, is useful for identifying nonlinearities present in the signals. Earlier studies used Bispectrum measurements to experimentally study the spectral energy transfer due to wavenumber interactions in a turbulent flow, which is briefly discussed in the manuscript. This is one of the main motivations for considering HOSE on Atmospheric signals. The Bicoherence obtained by this method has been applied to the backscattered signals received from the Mesosphere, Stratosphere, and Troposphere (MST) radar, Gadanki. Here we considered both convective and clear air atmospheric observations for the analysis and calculated the Nonlinear Index (which represents the amount of nonlinearity in signals) obtained from the Bicoherence for each range bin. We observed that the nonlinearity index indirectly provides information about turbulent intensity. An empirical relationship between the nonlinear index and turbulent energy dissipation rate has been established through regression models. The results of the turbulence energy dissipation rate (ε) obtained from the nonlinear index based method have been compared with the turbulence energy dissipation rate (ε) obtained from the spectrum width based method.

Significance of nanoparticle radius and inter-particle spacing toward the radiative water-based alumina nanofluid flow over a rotating disk

Abstract The study of nanofluid flow over a rotating disk has significant importance because of its enormous range of implementations, including cancer treatments, chemotherapy, nanomedicines, fermentation sciences, selective drug delivery, food sciences, biosensors, biomedicines, and electronics. Due to these applications of nanofluid, the present problem investigates the magnetohydrodynamic flow of nanofluid with nonlinear thermal radiation and viscous dissipation. In this analysis, the aluminum oxide nanoparticles are mixed with water. Furthermore, the mechanism for inter-particle spacing and radius of aluminum oxide nanoparticles on the dynamics of the two-dimensional flow of nanofluid are investigated. The present problem is modeled in the form of partial differential equations (PDEs), and these PDEs are converted into ordinary differential equations with the help of suitable similarity transformations. The analytical solution to the current modeled problem has been obtained by using the homotopy analysis technique. The main purpose of the present research work is to analyze the behavior of the velocity and temperature of the nanofluid for small and large radius of the aluminum oxide nanoparticles and inter-particle spacing. Also, the role of heat transport is computed for linear and nonlinear thermal radiation cases. The major findings and principal results of this investigation are concluded that the primary velocity of nanoliquid is augmented due to the intensification in suction parameter for both the small and larger radius of aluminum oxide nanoparticles. Furthermore, it is perceived that the heat rate transfer is larger when the Eckert number and nanoparticle volume fraction are higher for both nonlinear and linear thermal radiation cases.

Numerical simulation and regression analysis of MHD dissipative and radiative flow of a Casson nanofluid with Hall effects

The magnetohydrodynamic (MHD) flow of Casson nanofluid has several applications in engineering and medical processes. The present research work is performed to examine the unsteady viscous dissipative and radiative flow of a Casson nanofluid over a stretching sheet under the influence of a transverse magnetic field with a view to highlight the impact of Hall current. The mathematical model comprising of nonlinear coupled PDE is transformed into a set of coupled ODEs using appropriate similarity transformation. The reduced mathematical model in a similar form is then solved by adopting the successive linearization method (SLM). The residual analysis is used to validate the solutions. A parametric study is performed to inquire about the impacts of Hall current, nonlinear thermal radiation, viscous dissipation, and other pertinent flow parameters such as temperature ratio, Brownian movement, thermophoresis on the nanofluid velocities, temperature, and concentration. The effects of pertinent flow parameters are also examined on the skin-friction coefficients, Nusselt number, and Sherwood number. A quadratic regression analysis is presented to estimate the skin-friction coefficient and Nusselt number for different values of effecting parameters. Results reveal that the increasing values of Casson parameter decrease the fluid velocity and temperature, whereas a converse trend is detected in concentration profile, rate of heat transfer and mass transfer.

Double-diffusive peristaltic MHD Sisko nanofluid flow through a porous medium in presence of non-linear thermal radiation, heat generation/absorption, and Joule heating

This article studied a numerical estimation of the double-diffusive peristaltic flow of a non-Newtonian Sisko nanofluid through a porous medium inside a horizontal symmetric flexible channel under the impact of Joule heating, nonlinear thermal radiation, viscous dissipation, and heat generation/absorption in presence of heat and mass convection, considering effects of the Brownian motion and the thermophoresis coefficients. On the other hand, the long wave approximation was used to transform the nonlinear system of partial differential equations into a nonlinear system of ordinary differential equations which were later solved numerically using the fourth-order Runge–Kutta method with shooting technique using MATLAB package program code. The effects of all physical parameters resulting from this study on the distributions of velocity, temperature, solutal concentration, and nanoparticles volume fraction inside the fluid were studied in addition to a study of the pressure gradients using the 2D and 3D graphs that were made for studying the impact of some parameters on the behavior of the streamlines graphically within the channel with a mention of their physical meaning. Finally, some of the results of this study showed that the effect of Darcy number Da and the magnetic field parameter M is opposite to the effect of the rotation parameter Omega on the velocity distribution whereas, the two parameters nonlinear thermal radiation R and the ratio temperature {theta }_{w} works on a decrease in the temperature distribution and an increase in both the solutal concentration distribution, and the nanoparticle's volume fraction. Finally, the impact of the rotation parameter Omega on the distribution of pressure gradients was positive, but the effect of both Darcy number Da and the magnetic field parameter M on the same distribution was negative. The results obtained have been compared with the previous results obtained that agreement if the new parameters were neglected and indicate the phenomenon's importance in diverse fields.

Residual Quantum Effects beyond Mean‐Field Treatment in Quantum Optics Systems

AbstractMean‐field treatment (MFT) is frequently applied to approximately predict the dynamics of quantum optics systems. It simplifies the system Hamiltonian by neglecting the quantum statistics of certain modes that are driven strongly by lasers or couple weakly with other modes. However, the neglected quantum correlations between different modes result in unanticipated quantum effects and might lead to significantly distinct system dynamics. Here, a general and systematic theoretical framework based on perturbation theory in company with MFT is provided to capture these quantum effects. The form of nonlinear dissipation and parasitic Hamiltonian as well as their relationship to the nonlinear coupling rate are predicted. Furthermore, the indicator is also proposed as a measure of the accuracy of mean‐field treatment. As an example, this theory is applied to quantum frequency conversion, in which mean‐field treatment is commonly applied, to test its limitation under strong pump and large coupling strength. The analytical results show excellent agreement with the numerical simulations. This work clearly reveals the residual quantum effects neglected by MFT and provides a more precise theoretical framework for nonlinear optics and quantum optics.

Optimal L2-decay of solutions to the dissipative nonlinear Schrödinger equation in higher space dimensions

We study an optimal L2-decay of solutions to the Cauchy problem of the n-dimensional nonlinear Schrödinger equations with a long-range dissipative nonlinearity. Our purpose is to show that the optimal L2-decay of dissipative solutions is given by (log⁡t)−n/2 in higher space dimensions.

Reconciling nonlinear dissipation with the bilinear model of two Brownian particles.

The Brownian motion of a single particle is a paradigmatic model of the nonequilibrium dynamics of dissipative systems. In the system-plus-reservoir approach, one can derive the particle's equationsof motion from the reversible dynamics of the system coupled to a bath of oscillators representing its thermal environment. However, extending the system-plus-reservoir approach to multiple particles in a collective environment is not straightforward, and conflicting models have been proposed to that end. Here, we set out to reconcile some aspects of the nonlinear and the bilinear models of two Brownian particles. We show how the nonlinear dissipation originally derived from exponential system-reservoir couplings can alternatively be obtained from the bilinear Lagrangian, with a modified spectral function that explicitly depends on the distance between the particles. We discuss applications to the contexts of anomalous diffusion and of hydrodynamic interactions. Our results thus broaden the applicability of the bilinear model.

Blow‐up for a Von Karman equation with nonlinear dissipation, logarithmic source, and acoustic boundary conditions

In this paper, we address a Von Karman equation with nonlinear dissipation, logarithmic source effect, and acoustic boundary conditions. We devote to investigate a blow‐up result of the solutions corresponding to the equation. Owing to the presence of nonlinear dissipation instead of linear dissipation, we have some difficulty in use of the concavity method. Thus, using the energy method, we establish a blow‐up result of the solutions with some positive initial energy.

Recycled Plastic Lumber walls for one and two-story housing: An assessment of their seismic performance

Recycled Plastic Lumber (RPL) is a sustainable material that has been proposed in the last years to develop structural systems for low-rise housing in high-seismic hazard zones to reduce plastic pollution and housing deficit. Recently, experimental and analytical studies have been conducted to determine the behavior and the damage states of RPL walls under cyclic loads, and promising results have been obtained. Based on that results, a Mostaghel’s six-lines hysteretic model was implemented to simulate the nonlinear behavior and energy dissipation capacity of the RPL walls. Subsequently, the seismic performance assessment of the RPL walls was obtained by nonlinear dynamic analyses using the FEMA P-695 far-field ground motions, which allowed develop fragility functions to estimate the probability of exceeding certain damage states as a function of an intensity measure of seismic hazard. The results of this study evidence that the RPL walls have a suitable seismic performance for their implementation in low-rise housing and meet precisely the Basic Safety performance objective established in the design philosophy of the NSR-10 Colombian building code for this kind of buildings.

Attractors of a Weakly Dissipative System Allowing Transition to the Stochastic Web in the Conservative Limit

This article deals with the dynamics of a pulse-driven self-oscillating system — the Van der Pol oscillator — with the pulse amplitude depending on the oscillator coordinate. In the conservative limit the “stochastic web” can be obtained in the phase space when the function defining this dependence is a harmonic one. The paper focuses on the case where the frequency of external pulses is four times greater than the frequency of the autonomous system. The results of a numerical study of the structure of both parameter and phase planes are presented for systems with different forms of external pulses: the harmonic amplitude function and its power series expansions. Complication of the pulse amplitude function results in the complication of the parameter plane structure, while typical scenarios of transition to chaos visible in the parameter plane remain the same in different cases. In all cases the structure of bifurcation lines near the border of chaos is typical of the existence of the Hamiltonian type critical point. Changes in the number and the relative position of coexisting attractors are investigated while the system approaches the conservative limit. A typical scenario of destruction of attractors with a decrease in nonlinear dissipation is revealed, and it is shown to be in good agreement with the theory of 1:4 resonance. The number of attractors of period 4 seems to grow infinitely with the decrease of dissipation when the pulse amplitude function is harmonic, while in other cases all attractors undergo destruction at certain values of dissipation parameters after the birth of high-period periodic attractors.

Destruction of solutions for class of wave $ p(x)- $bi-Laplace equation with nonlinear dissipation

<abstract><p>An initial value problem is considered for the nonlinear dissipative wave equation containing the $ p(x) $-bi-Laplacian operator. For this problem, sufficient conditions for the blow-up with nonpositive initial energy of a generalized solution are obtained in finite time where a wide variety of techniques are used.</p></abstract>

A Five-Point TENO Scheme with Adaptive Dissipation Based on a New Scale Sensor

In this paper, a new five-point targeted essentially non-oscillatory (TENO) scheme with adaptive dissipation is proposed. With the standard TENO weighting strategy, the cut-off parameter $C_T$ determines the nonlinear numerical dissipation of the resultant TENO scheme. Moreover, according to the dissipation-adaptive TENO5-A scheme, the choice of the cut-off parameter $C_T$ highly depends on the effective scale sensor. However, the scale sensor in TENO5-A can only roughly detect the discontinuity locations instead of evaluating the local flow wavenumber as desired. In this work, a new five-point scale sensor, which can estimate the local flow wavenumber accurately, is proposed to further improve the performance of TENO5-A. In combination with a hyperbolic tangent function, the new scale sensor is deployed to the TENO5-A framework for adapting the cut-off parameter $C_T$, i.e., the local nonlinear dissipation, according to the local flow wavenumber. Overall, sufficient numerical dissipation is generated to capture discontinuities, whereas a minimum amount of dissipation is delivered for better resolving the smooth flows. A set of benchmark cases is simulated to demonstrate the performance of the new TENO5-A scheme.

Noise-dissipation Correlated Dynamics of a Double-well Bose-Einstein Condensate-reservoir System

Abstract: In this work, we study the dissipative dynamics of a double-well Bose-Einstein condensate (BEC) out-coupled to reservoir at each side of its trap. The sub-system comprises of a simple Bose-Hubbard model, where the interplay of atom-tunneling current and inter-particle interaction are the main quantum features. The contact with two separate heat baths causes dissipation and drives the system into a non-equilibrium state. The system is well described by the Generalized Quantum Heisenberg-Langevin equation. We considered two Markovian dissipative BEC systems based on (i) the mean-field model (MF), where the internal noise has been averaged out and (ii) the noise-correlated model (FDT). Physical quantities, such as population imbalance, coherence and entanglement of the system, are computed for the models. The two-mode BEC phases, such as the quantum tunneling state and the macroscopic quantum-trapping state, evolved into complicated dynamics by controlling the non-linear interaction and dissipation strengths. We found that many important quantum features produced by the noise-correlated FDT model are not captured by the mean-field model. Keywords: Double-well BEC, Dissipation, Noise, Markovian, Non-Markovian, Fixed points. PACS: 03.75 Lm, 03.65 Yz, 03.75 Gg, 05.

Domain wall dynamics in cubic magnetostrictive materials subject to Rashba effect and nonlinear dissipation

Domain wall dynamics in cubic magnetostrictive materials subject to Rashba effect and nonlinear dissipation