Analysis Of Dissipation Research Articles

Investigation of wave dissipation performance in various perforated Caisson designs using the SPH method

ABSTRACT The perforated caisson structure is used in ports and waterways for its wave dissipation performance. This study modifies the traditional SPH method using the Riemann solution and CSPH method to examine the interaction between waves and perforated caissons. A comparative analysis of wave dissipation between single- and double-chambered caissons was conducted, considering various wave conditions. Results show that the best wave dissipation occurs when the perforation ratio of the front plate is higher than that of the back plate, and the front chamber is narrower than the back chamber. Equal chamber widths are beneficial for adapting to diverse wave conditions and minimizing reflection. Additionally, the wave dissipation process of the double-chambered caisson is described in detail, with an analysis of the movement states of characteristic water particles at specific moments.

Power dissipation and thermal analysis of PMSM driver based on SIC MOSFETs

Power dissipation and thermal analysis of PMSM driver based on SIC MOSFETs

Design of Multilayered XOR Gate Using Quantum Dot Cellular Automata

The rapid advancement of microelectronics technology necessitates the development of high-speed, low-power devices. Quantum Cellular Automaton (QCA) is emerging as a promising technology enabling logic circuits with exceptional operating speeds. The XOR gate is crucial in nanocomputing applications, such as nano-processors and nano-communication units, and requires innovative design approaches. This paper presents a novel design of an XOR gate using a multilayered layout methodology within the QCA framework. The circuit’s design and validation are performed using QCADesigner 2.0.3, while energy dissipation analysis is conducted with QCADesigner-E, resulting in an energy dissipation of 15 meV. Comprehensive parameter analysis, including cost functions, highlights the superiority of the proposed design. A comparative analysis with similar existing multilayered designs shows a 55% improvement in QCA-specific quantum cost. Notably, the proposed design eliminates the need for internal nodes within the layout, enhancing the methodology’s applicability to higher-order and more complex circuits.

Design and Energy Dissipation Analysis of a Boring Bar Based on Particle Damping

Design and Energy Dissipation Analysis of a Boring Bar Based on Particle Damping

Dissipative disorder analysis of Homann flow of Walters B fluid with the applications of solar thermal energy absorption aspects

Encountering of entropy generation is meaningful while investigating the energy loss during the operational mechanical system. In particular, the flow of fluid experiencing friction drag and due to which a significant amount of heat transfer occurred. Thus, the thermodynamic system energy conversion is one of the measures of the lost available work and is known as irreversibility. Avoiding of such energy loss can be minimized by introducing the concept of hybridization during the liquid dynamics. This work is initiated to formally characterize and address the significance of irreversible process during the typical Homann flow of viscoelastic liquid. The flow with heat and mass balance aspects are further characterize with the inclusion of thermophoretic and Brownian motion factors. The flow configuration is interpreted in terms of gravitationally affected vertical cylindrical disk, for a better understanding of the impact of irreversible processes, more physical effects in terms of heating source/sink, chemical reaction and solar thermal radiation. New physical impacts are described numerically in terms of flow speed temperatures, nanoparticle volume fraction, displacement thicknesses and entropy generation. Perturbation method is utilized for the reduction of the fourth-order mathematical equation for reducing the problem in to well-posed from ill-posed status. The numerical analysis is carried out by applying one of the built-in commands while using MATLAB software. The buoyancy force factor enhanced the liquid speed, and the concentration of the liquid was determined with uplifted conduct for higher values of chemical reaction parameters. The overall entropy rate is reduced as the Brinkman number and magnetic parameter are increased. The heat transfer flow is increased by internal heat generation. Higher Prandtl and Schmidt numbers significantly affected the isotherms and volume fraction contours.

Study on desorption mechanism and thermal stability of OTS coating as an anti‐relaxation material

AbstractThis research explores the desorption mechanism and thermal stability of octadecyltrichlorosilane (OTS, CH3(CH2)17SiCl3) coating on quartz slides and in alkali‐metal vapour cells. The morphological thermal‐changes, energy dissipation diversity, and anti‐relaxation characteristic of OTS coatings before and after exposure to Cs atoms by Fourier transform infrared spectroscopy, water contact angle measurement, atomic force microscopy imaging, collision energy dissipation analysis, and free induction decay of Cs atoms are measured systematically. The results show that the OTS coatings exhibit the best thermal stability under the specific process conditions, and the homogeneous and dense structure makes the adsorption of alkali‐metal atoms more stable, which effectively reduces surface energy dissipation and prolongs the relaxation time of Cs atoms. The study provides certain reference for efficient anti‐relaxation coating fabrication and coated cell application.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) based prevalence and dissipation analysis of acetamiprid and bifenthrin in okra after foliar application

ABSTRACT The acetamiprid, and bifenthrin residues levels in the okra crop were assayed using a QuEChERS extraction method combined with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The technique was subsequently checked for linearity, matrix effect, recovery, repeatability, reproducibility, and limit of quantification (LOQ). A salting-out mixture comprising magnesium sulphate, sodium chloride, disodium hydrogen citrate sesquihydrate and trisodium citrate dihydrate offered quick and rapid extraction of acetamiprid and bifenthrin residues from okra. The devised method was found to be linear for the recovery of acetamiprid and bifenthrin with regression coefficients (R2 ) of 0.9577 and 0.9698, respectively. After applying a ready-made mixed formulation of acetamiprid (25 g a.i. ha−1) and bifenthrin (12.5 g a.i. ha−1), the average initial deposits on okra vegetables were 0.175 mg/kg and 0.062 mg/kg, respectively. The residues of acetamiprid and bifenthrin fell below the LOQ of 0.01 mg/kg after 14 and 4 days of foliar spray, respectively. The dissipation kinetics of acetamiprid and bifenthrin followed first-order kinetics with half-life values (t1/2) of 3.74 and 2.18 days, respectively. The comparison between observed levels of acetamiprid and bifenthrin and European Union Maximum Residual Limits reveals it is safe to harvest okra one day after applying the recommended dose. Overall, the salting out conditions followed by liquid chromatography coupled with tandem mass spectrometry may provide a rapid and pragmatic solution for analysts and stakeholders to ensure the adherence to the safety and responsible use of these pesticides in agriculture

Analysis of the Deformation Energy Dissipation in a Layered Medium Under Dynamic Loading (On the Example of Highways)

Analysis of the Deformation Energy Dissipation in a Layered Medium Under Dynamic Loading (On the Example of Highways)

Research of tangential cyclic loading on mechanical properties between cosine contact surfaces

Abstract The investigation of the mechanical properties of contact surfaces under tangential cyclic loading is very important for understanding the stiffness and damping of combined structures. In this paper, using Hertzian contact theory and Coulomb's friction law, the contact mechanical mechanism of a common cosine cylindrical contact model subjected to tangential loading, unloading, and reloading is investigated, and the load-displacement curves (hysteresis curves) and the energy equations of a complete displacement cycle are deduced. The results show that under the action of tangential cyclic load, the shear stress increases immediately, and the micro slip zone outside the contact area gradually expands inward until it becomes a slip zone. At this point, the hysteresis curve changes from a "shuttle shaped" to a "quadrilateral" shape. In addition, nonlinear finite elements are used for static simulation to verify the accuracy of the hysteresis curve, tangential stiffness, and energy dissipation analysis of the cosine contact model under different axial crossing angles. The energy equation's fluctuation with tangential displacement under different conditions, as well as the impact of friction coefficient, axial intersection angle of the contact surface, external load, and cosine surface characteristics on the mechanical properties of the contact surface. With the increase of surface roughness or normal load, energy increases nonlinearly with the increase of displacement. Finally, when the Von Mises stress reaches the yield limit, reciprocating displacement loading will lead to plastic accumulation, resulting in wear and tear.

Hydraulic dissipation analysis in reversible pump with a novel double-bend impeller for small pumped hydro storage based on entropy generation theory

Hydraulic dissipation analysis in reversible pump with a novel double-bend impeller for small pumped hydro storage based on entropy generation theory

Repercussions of thermally stratified magnetic dipole for mixed convectively heated Darcy-Forchheimer Carreau-Yasuda nanofluid flow via viscous dissipation analysis

Nowadays nanotechnology is progressing speedily with the passage of time, consequently the research on innovative fluid termed as nanofluid is at its peak. Invention of nanofluid has made a revolution in engineering and chemical processes due to its enhanced heat transmission characteristics along with environmental friendliness as well as financially affordability of nanofluid are causes of its attraction among the research community. In current study the basic aim is to scrutinize a rheological ferrofluid model with magnetic effects. The procedure for conversion of coupled P.D. Es into coupled set of O.D.Es which is performed by use of similarity variables. The numerical scheme used here is bvp4c scheme for obtaining the required numerical outcomes. A comprehensive review of graphical illustration for fluid's temperature, velocity as well as concentration is delivered here. We inspected that with upsurge of parameter for Brownian motion resultantly concentration of fluid declines while increase in thermal profile is noted.

Analysis of flow and energy dissipation in pump turbine with small guide vane opening

In this study, a detailed flow state analysis of a reversible pump turbine (RPT) under small guide vane opening conditions was conducted using both numerical simulation and experimental methods on three analysis planes at 0.5 span. The entropy production rate (EPR) in entropy production theory was utilized to visualize the location and magnitude of energy losses in the flow process. The focus was placed on the coherent vortex structures in the volute, stay vane, guide vane, and runner flow path. The results demonstrate that, throughout the runner’s cycle, the leading edge of the guide vane experiences low-pressure regions with uneven pressure distribution within the runner channel. Velocity streamlines reveal flow separation and vortex generation at the typical guide vane trailing edge, with a maximum velocity reaching 49.7. Analysis of radial force and torque on typical guide vanes and the runner indicates that radial force and torque on the guide vanes do not significantly change, with the radial force coefficient CF r−x varying between 0.254 and 1.3. Major energy losses are concentrated behind the trailing edge of the guide vane, primarily in the form of jet wake. Coherent vortex structures are observed in the volute, stay vane, guide vane, and runner flow path, with slight turbulent wake at the trailing edge of the stay vane, clear shedding vortex streets, and vortex build-up in the bladeless area between the guide vane and the runner.

Numerical solutions and stability analysis of hybrid Casson nanofluid flow with MHD and heat transfer effects

AbstractThis research addresses the complex dynamics of hybrid Casson nanoliquids in flow and heat transfer applications, focusing on the interaction between fluid dynamics and thermal phenomena in the presence of magnetohydrodynamics (MHD), viscous dissipation, and Joule heating. The motivation behind this study stems from the need to enhance the efficiency of heat transfer processes in various engineering applications, such as cooling systems and electronic devices, where hybrid nanofluids can offer superior thermal performance compared to conventional fluids. The novelty of this work lies in its comprehensive numerical investigation of a hybrid Casson nanoliquid over a moving permeable surface, incorporating a detailed analysis of MHD effects, viscous dissipation, and Joule heating. Using the Tiwari and Das model to formulate the governing equations, the study employs similarity transformations to convert these equations into a system of ordinary differential equations (ODEs). MATLAB is then used to derive numerical solutions, with a stability analysis ensuring the physical dependability of these solutions. Key findings reveal that the temperature distribution of the hybrid nanoliquid shows a positive correlation with both Prandtl and Hartmann numbers. Additionally, a positive relationship between temperature and the Eckert number is observed. These insights offer valuable guidance for engineers aiming to optimize heat transfer processes using hybrid nanofluids, highlighting their potential for improved thermal management in practical applications.

Heat dissipation analysis on the designed inner-outer circulation impingement double-layer microchannel heat sinks with chamfers in power electronic cooling system

This study discusses a new design which utilizes chamfers to further improve the thermal performance of inner-outer circulation impingement double-layer microchannel heat sinks by simulations and experiments manufactured with 3-Dimension printing. In contrast to former designed inner-outer circulation impingement double-layer microchannel heat sinks, inner-outer circulation impingement double-layer microchannel heat sinks with chamfer shows significant advantages in improving overall thermal performance in power electronic cooling. The results of simulation are in good agreement with those of experiment in five 3-Dimensional printing tests. It is demonstrated that the introduction of chamfers is effective in controlling the thermal gradient on substrate of heat sinks, and reducing the peak temperature on substrate of inner-outer circulation impingement double-layer microchannel heat sinks with chamfer as a result. The best performance is presented by a 0.2 mm chamfer located on the corner of the inner-outer circulation shaft in inner-outer circulation impingement double-layer microchannel heat sinks with chamfer. Experimental studies and numerical simulations both indicate that inner-outer circulation impingement double-layer microchannel heat sinks with a 2 mm chamfer significantly enhances heat transfer characteristics. In addition, the average Nusselt number for inner-outer circulation impingement double-layer microchannel heat sinks with a 2 mm chamfer is higher than that of other tests. Moreover, inner-outer circulation impingement double-layer microchannel heat sinks with a 2 mm chamfer performs better than other designs in terms of the overall heat transfer performance, which is significantly better than inner-outer circulation impingement double-layer microchannel heat sinks without chamfers.

Implementation of EXOR and Subsequent Modular Circuits for Application at Nanoscale Level

Evolving as an outperforming nanotechnology, quantum-dot cellular automata (QCA) is being efficiently used for the design and development of digital modules. This paper presents a novel design for an ultra-efficient exclusive-OR (EXOR) gate in QCA nanotechnology using the cell translation technique. The analysis for fault tolerance and power dissipation of the proposed design is also assessed. To establish the effectiveness of the proposed design, an extensive comparison with the existing designs is provided. As a test bench implementation, the proposed EXOR gate is available as a module for the development of a parity checker, a full subtractor, and a 4-input binary to gray (B2G) code converter in QCA. The cell count for the proposed design of the EXOR gate, full subtractor, parity checker, and 4-input B2G converter is 8, 35, 24, and 24, and the total area (µm2) is 0.0039, 0.0259, 0.01749, and 0.0129, respectively. The proposed EXOR gate design outclasses the hitherto prevailing designs both in terms of the operational parameters and the dissipation of energy. The design simulations have been performed in QCA Designer 2.0.3, and the energy dissipation analysis has been executed in QCA Designer-E and QCAPro.

Parameter Identification and Energy Dissipation Analysis of Premium Connections Based on the Iwan Model

The premium connection is an important section of the tubing column. Under intricate downhole conditions, axial vibration generates alternating loads that cause energy dissipation between the sealing surfaces of the premium connection, reducing sealing performance. To investigate this issue, the mutual conversion process of sticking, slipping, and macroscopic slipping stages between the sealing surfaces of the premium connection under axial loads must be assessed. In this study, a finite element analysis model of a taper–taper Φ88.9 mm × 6.45 mm P110 premium connection is developed based on the discrete Iwan model’s ontological relationship, and the sealing surface’s force–displacement hysteresis curve is obtained. The equivalent Iwan model for this particular premium connection is constructed by discretizing the hysteresis curve and identifying the model’s four sets of parameters. The correctness of the parameter identification method of the equivalent Iwan model is verified by comparing and analyzing the similarity of the two models. The energy dissipation in the sealing surfaces of the premium connection for different working conditions under dynamic loading is analyzed. This study reveals that the area similarity of the hysteresis curves of the two models is more than 92%, while the positional error is less than 2%. The sealing surface displacement amplitude of the premium connection is between 0.04 mm and 0.07 mm, while the sealing surface energy dissipation increases linearly, which may lead to a decline in sealing performance.

Enhancing dynamic mechanical properties of cemented lithium mica tailings backfill with alkaline rice straw fibers: Experimental investigation and microscopic analysis

Cemented lithium mica tailings backfill (CLMTB) faces dynamic loads from mining operations, affecting its stability. This study investigates the use of alkaline rice straw fibers (ARSF) to enhance CLMTB's dynamic properties. Dynamic impact tests were conducted on CLMTB specimens with varying ARSF contents, revealing that dynamic compressive strength (DCS) increased with ARSF up to 0.45% before decreasing. DCS improved with rising strain rates. The research includes analyses of stress-strain behavior, failure patterns, and energy dissipation during impacts, with scanning electron microscopy revealing the microstructural effects of ARSF on CLMTB. The findings suggest that ARSF effectively mitigates the damaging impacts of loads, significantly reducing crack development in CLMTB.

Numerical analysis of energy dissipation due to eddy currents in a vibrating beam

Vibration attenuation is a key aspect of mechanical engineering. One method to achieve this is through eddy currents, which can be generated in a vibrating system when a magnetic field is present, creating forces that oppose motion. This study examines a mechanical system consisting of a thin cantilever beam vibrating in a uniform and time-invariant magnetic field under steady-state conditions to understand the nature of energy dissipation and the relationship between motion, eddy currents, and damping forces. The calculation of eddy currents generally requires the use of complex numerical procedures. However, for systems with simple geometry, such as a cantilever beam, a recent numerical procedure based on the finite difference method, known for its simplicity in implementation, has been adapted and expanded to determine eddy currents under motional induction. A numerical application has been developed in which the vibration of a specific beam is characterised by its bending or torsional mode shapes, and the nature of the corresponding dissipative forces is analysed. Results indicate that the eddy currents are an effective means of dissipating energy at lower-order modes. Additionally, the direction of the applied magnetic field can induce coupling between bending and torsional vibrations.

Analysis of heat generation and viscous dissipation with thermal radiation on unsteady hybrid nanofluid flow over a sphere with double-stratification: Case of modified Buongiorno's model

PurposeThis work uses entropy generation analysis to numerically analyze magnetohydrodynamics (MHD) unsteady flow, heat and mass transfer. The study considers changing viscosity, thermal radiation, viscous dissipation, mass suction, heat generation, and stratification processes in a hybrid nanofluid around a spinning sphere. A two-phase nanofluid flow model (Buongiorno model) is used to tackle the current challenge. Both the free stream velocity and the sphere's angular velocity changed over time. Design/methodology/approachThe case study's complicated partial differential equations are transformed into simpler ordinary differential equations utilizing similarity transformation. Implementing the fourth-order Runge-Kutta Fehlberg method with a shooting scheme in MATHEMATICA has allowed us to get numerical solutions for ordinary differential structures. FindingsThe many aspects of these regulated physical characteristics have been elucidated and thoroughly examined via the use of charts and tables. For increasing values of unsteadiness parameter, the velocity profiles in the x-direction grow while they decrease in the z-direction. On the other hand, the temperature profile exhibits a dual pattern, and the concentration profile decreases. As the chemical reaction parameter climbs from 0.25 to 1.0, the Sherwood number for the nanofluid rises by 6721.39% and for the hybrid nanofluid, 3818.9%. When Nr increases from 0.2 to 0.8, nanofluid Nusselt number climbs 22.5% and hybrid nanofluid's Nusselt number rises 21.9%. The Brinkmann number and nanoparticle volume percentage are strongly associated with entropy production. Entropy generation is dual for the temperature difference, magnetic, radiation, and changeable viscosity parameters. The findings are also compared to those from the existing literature and are in excellent agreement with them.

Efficient quantum-dot adder optimisation and analysis for future circuits

ABSTRACT In recent years, the rapid scaling of transistors has necessitated the exploration of advanced alternatives to Complementary metal oxide semiconductor(CMOS) technology for future progress. Quantum-dot cellular automata(QCA) technology has emerged as a promising solution, offering highly dense, high-speed, and low-power circuits. Among the critical digital building blocks, adder circuits play a crucial role in arithmetic and logic units. Consequently, optimising these circuits in terms of area, delay, and quantum cost is essential for the development of efficient designs. This paper presents effective multi-layer n-bit ripple carry adder(RCA) circuits, utilising full adder(FA) circuit. The outputs are generated in distinct layers and verified using the QCADesigner-Ev2.2 tool with bi-stable and coherence vector energy setups, employing Euler and Runge-Kutta methods.Additionally, the proposed designs are evaluated for various design metrics at three different scale factors(1,0.8889,and 0.7778), corresponding to cell sizes of 18 × 18 nm , 16 × 16 nm , and 14 × 14 nm respectively. The temperature’s impact on the average output polarisation of the FA is explored. The research demonstrates an n-bit-RCA surpassing existing designs with cost optimisations of 89.5%, 86%, and 90.3% for 4-bit,8-bit and 16-bit circuits, respectively. The paper also provides a thorough energy dissipation analysis for the proposed adder design.