Principle Of Conservation Of Energy Research Articles

Scientific exploring of Marangoni convection in stagnation point flow of blood-based carbon nanotubes nanofluid over an unsteady stretching surface

This study examines Marangoni convection in blood-based carbon nanotubes nanofluid's stagnation point flow over a time-dependent stretching surface. This study is inspired by the emerging importance of nanofluids in a variety of scientific and technical fields due to their unique and varied uses and effective thermal activities. Some examples of potential applications of these fluids include cancer treatment, magnetic refrigeration, drug delivery, and magnetic resonance imaging. Two types of nanoparticles are considered name is single wall carbon nanotube and multi wall carbon nanotube blood is takin as base fluid. Nonlinear partial differential equations are used to simulate the specified flow issue using momentum and energy conservation principles. Using a similarity transformation, the resultant is transformed into nonlinear with reduced dimensions. The relations for velocity profile and temperature distribution are calculated from the developed nonlinear ordinary differential equation by using an approximate analytical technique called the homotopy asymptotic method. Subsequently, these equations are implemented and executed within Mathematica software. The investigation focuses on significant outcomes such as momentum filed, energy filed, Skin friction coefficients, and Nusselt number. Graphs are used to interpret the effects of several factors, including the Marangoni parameter, nanoparticle volume friction, stretching parameter, slip parameter, and Prandtl number. The behavior of Nusselt's number and skin friction coefficient was also checked with the help of graphs and tables. The convergence of the solutions is checked with the help of auxiliary functions as well.

Damage mechanisms and analytical model of CFRP laminate under low-velocity normal and oblique impacts

The present work investigates the energy absorption performance of carbon fibre-reinforced polymer (CFRP) laminates subjected to low-velocity normal and oblique impacts. Experimental tests are conducted on laminates exposed to varying impact energies at both normal and oblique angles. The numerical model is developed to simulate the dynamic response of the CFRP. The research employs a combination of experimental and numerical methods to reveal the underlying damage mechanisms. The changes observed in the oblique impact response are explained through an analysis of the damage mechanisms. Analytical models for each energy absorption mechanism are proposed based on the principles of energy conservation and the theory of large bending deformation of anisotropic materials. The energy absorption performance of the laminates under oblique impacts, considering rebound and penetration conditions, is discussed. It is found that the delamination is the primary energy absorption mechanism of CFRP laminate under rebound conditions, while elastic deformation of fibres is the primary energy absorption mechanism under penetration conditions. Furthermore, the energy absorption performance of the laminate is found to be affected by the peak force and effective thickness of the plate, which change with the oblique angle. This paper makes a significant contribution by utilising experimental, numerical, and theoretical approaches to gain insights into the damage mechanisms of laminates subjected to oblique impacts.

Energy structure perspective as an innovative approach to basic study of different analysis of complex robotic systems

In this paper, the idea of using the energy structure perspective for application in the study of complex robotic systems is presented and expanded. The perspective of energy structure can provide a powerful solution for analyzing robotic systems. In fact, among the special capabilities of this approach, it can apply the energy conservation principle simultaneously by considering the effects of related energy wastes during system operation, the possibility of considering movement restrictions in the equation of the energy structure and applying it in the equation explained the movement of the system simultaneously with the first and second laws of thermodynamics, the calculation of the dynamic energy of the system using its movement restrictions, as well as how to apply energy directly, etc. Based on this, the perspective of energy structure can be helpful in studies related to robotic systems, especially systems with specific complexities and different behavioral and movement aspects. This paper develops the fundamental aspects of this issue.

Energy Structure Theory: A General Unified Thermodynamics Theory

This study, while reviewing some of the established unified equations and fundamentals of the energy structure and providing a detailed interpretation of their physical concepts, expands the relevant equations for new topics and applications, and in fact, establishes novel results and equations from the energy structure analysis. In fact, this paper establishes an energy components-based-general model inspired by the first and second laws of thermodynamics as well as using a new division to the total energy of the system. The established model is completed by extracting the physical direction for the feasible processes based on the energy components of the system. As two of the most important achievements of the energy components approach, using a new quasi-statistical approach as well as a novel energy conservation principle, an entropy equation is gained that has a common basis as the Boltzmann entropy equation as well as a general solution to the different formulations of the second law of thermodynamics is established. The established equations are gained without any limiting assumptions, and are governed to any physical system. Several basic examples have been studied, and matching the obtained results with expected ones is shown.

Classical Evolution without Evolution

The well-known argument of Page and Wootters demonstrates how to “derive" the usual quantum dynamics of a subsystem in a global state which is an eigenstate of the total Hamiltonian. I show how the same argument can be made in classical physics by using a formalism that closely resembles the quantum one. This is not surprising, since the Hamilton–Jacobi formulation of classical dynamics is precisely motivated by the logic of timeless dynamics. Ultimately, the key to obtaining dynamics without dynamics is the principle of energy conservation which leads to correlations between times pertaining to different subsystems. The same can, of course, be said about all other conserved quantities, and we show how to address this problem in its full generality so as to realise rotation without rotation, translation without translation and so on. The classical and quantum interpretations do, however, have one major difference and this is the Church of the Higher Hilbert Space interpretation of mixtures, which only exists in quantum physics. We discuss a few consequences of this point.

A novel analytical framework for assessing the impact response of SFRC beam

This paper presents a novel model for predicting the impact response of steel fiber reinforced concrete (SFRC) beams. The model utilizes the principles of energy conservation and impulse-momentum theorem to calculate the maximum reaction force and peak impact force. A tensile behavior model for simulating the concrete behavior is proposed considering the effect of volume fraction of steel fibers and the effect of strain rate on the concrete properties. Additionally, the conventional beam theory, along with a cross-section-layered approach, is used to express the total beam's reaction forces vs deflection relationship. Afterwards, the model calculates the maximum midspan deflection of SFRC beams subjected to impact loading by applying the principle of conservation of energy and considering the effect of strain rate. The proposed model is compared with 121 impact tests, and the results show that the model can estimate the maximum reaction force of SFRC beams with acceptable accuracy.

Effect of valve on ballistic performance in supercritical CO2 pneumatic launch

To investigate the impact of the launch valve on the performance of the supercritical CO2 pneumatic launch, a numerical model was developed based on the principles of mass and energy conservation. Specifically, the thermos-physical properties of real gas were used to describe CO2 during the launch process. Expansion experiments were conducted to validate the numerical model's accuracy. The study also examined the effects of the valve's opening mode, full opening time, and full opening area on launch performance. The findings indicate that when using the same launch valve, a decrease in the full opening time of the valve leads to an increase in the average temperature of the low-pressure chamber. Additionally, injecting the medium into the low-pressure chamber at a faster rate results in improved working responsiveness and energy conversion efficiency. Once the valve reaches a certain size, further increases offer little benefit. The parabolic valve is the optimal choice for both overload and final velocity. However, if the aircraft can handle it, a quick-opening valve will result in a shorter launch time and higher final velocity. This study offers theoretical guidance to improve the precision of aircraft cold launches.

Computations for efficient thermal performance of Go + AA7072 with engine oil based hybrid nanofluid transportation across a Riga wedge

The demand for efficient heat transportation for the reliable functioning of mechanical processes is rising. The hybrid nanofluid emulsion is a related new concept in this research field. This communication pertains to mass and thermal transportation of Graphene oxide (Go) + AA7072 to be dissolved homogeneously in the bulk engine oil. In order to demonstrate the effectiveness of this hybrid nanofluid, a simple nanofluid Go/engine oil is also discussed. The flow of fluids occurs due to stretch in the wedge adjusted with Riga surface. The design of a hybrid nanofluid manifests the novelty of the work. The system of partial differential equations that are based on conservation principles of energy, momentum, and mass are transmuted to ordinary differential form. Numerical simulation is carried out on the Matlab platform by employing the Runge-Kutta approach along with a shooting tool. The influential parameters are varied to disclose the nature of physical quantities. The flow is accelerated with higher attributes of the modified Hartmann number, but it decelerates against the Weinberg number. The fluid's temperature rises with increment, in the concentration of nano-entities. The velocity for hybrid nanofluids is slower than that of mono nanofluids and the temperature distribution for hybrid nanofluids is greater than that of mono nanofluids. The fluid temperature increases with the concentration ϕ2 of AA7072.

Model Establishment of Chip Air Cooling Process and Its Proportional Integral Differential Tuning

Abstract Chip junction temperature is a key factor affecting the normal operation of the chip. The development of integrated circuit technology brings about high integration and low cost, but it also puts forward higher requirements for the cooling system. This paper focuses on the air cooling of the chip, builds a hardware test platform based on MCS-52, the general name of the intel series microcontroller unit, and sets up a mathematical model of the air cooling process of the chip on the matlab platform based on the principle of energy conservation, heat transfer theory and finite element method. By proposing the equivalent convective heat transfer coefficient, the thermal resistance of the system can be well estimated. This model can easily realize the joint simulation of chip, heat radiator, and control strategy, which overcomes the disadvantage that traditional finite element simulation software are difficult to combine with control strategy. In addition, based on the model, the proportional integral differential (PID) control parameters are automatically optimized, achieving excellent temperature control effect, and proving the feasibility of optimizing the control parameters through the model.

Biomass solar fast pyrolysis with a biomimetic mini heliostat field and thermal receiver for nitrogen heating

Biofuels may significantly influence the world's transition from hydrocarbons to renewable energies. Pyrolysis uses thermal energy in an anaerobic ambiance to crack biomass and create biofuels (bio-oil and synthesis gas). This work reports a detailed computational study of a novel system to develop fast biomass pyrolysis with concentrated solar energy. A fluidized bed reactor was coupled to a solar thermal receiver to heat the inert fluid (nitrogen) using a biomimetic mini heliostat field which provides the required thermal energy. A detailed kinetic model for the pyrolysis of lignocellulosic biomass was solved simultaneously with a set of differential equations based on mass, momentum, and energy conservation principles. An Eulerian-Eulerian approach was considered with three phases. The computational model was compared with data reported in the literature for the fluidized bed reactor and heat transfer in the solar thermal receiver with good agreement. Concentrated solar fluxes on the receiver, nitrogen outlet temperatures, temperature contours inside the reactor, concentration contours of relevant gases, and global product percentages (Tar, Char, and Gas) are reported. The products reach an almost constant composition of Gas, Tar, and Char after 6 s of reaction, indicating the annual operational stability of the solar pyrolysis plant in terms of biofuel production.

Momentum work and the energetic foundations of physics. I. Newton’s laws of motion tailored to processes

Modern physics is based on Newton’s laws of motion, which describe interaction via forces. In this paper, we argue that interaction needs to be described in terms of processes. By introducing the momentum work and the associated momentum energy in mechanics, we present a coherent formulation of the process equations for mechanics and thermodynamics. This naturally leads to a simple derivation of the Lorentz-transformed mass, according to which any object changes its mass in real terms when its velocity is changed. Momentum work requires a revision of Newton’s laws of motion. For the first time in the history of physics, the elastic collision between objects, such as particles, can be described as a temporal process, not as interaction via force = counter-force. The mechanism of energy conversion during the elastic collision and other mechanical processes, such as free fall, becomes clear and demonstrates the validity of the principle of energy conservation on microscale at any point in time. The results suggest that physics can be rebuilt on a more coherent footing of dynamic processes up to quantum-process thermodynamics.

Integration of CFD simulated abrasive waterjet flow dynamics with the material removal model for kerf geometry prediction in overlapped erosion on Ti-6Al-4V alloy

Complex surfaces in difficult-to-machine materials can be milled by maneuvering the abrasive waterjet (AWJ) according to the local part geometry by suitably overlapping the kerf cross-sectional profiles (CPs). The CP of a kerf milled in a single pass (i.e., trench) and overlapped pass (i.e., cavity) erosion by the AWJ are the building blocks that need to be known apriori for developing a jet path strategy to achieve a complex surface. This demands an efficient model for the kerf CP prediction. The present work proposes a novel framework for overlapped kerf CP prediction, wherein the jet characteristics of the AWJ exiting the focusing tube are evaluated from the two-phase flow computational fluid dynamics simulation coupled with the material removal model developed based on energy conservation principles. Towards incorporating the non-linearities observed in the kerf formation from the overlapped experimental trials into the model for CP prediction enhancement, the following are considered: (i) a hypothesis: ‘secondary erosion by the jet on the previously eroded kerf increases material removal’, (ii) the varying jet-material property of the ductile material (Ti-6Al-4V alloy), and (iii) local particle impact angles. Furthermore, the variation in the above mentioned non-linearities is incorporated into the model under the change in the AWJ conditions. From the results, it is observed that the proposed models predicted (i) the trench CP with a mean absolute error (MAE) of 27 μm, and the maximum erosion depth (hmax) with an error < 2%, and (ii) cavity at different overlaps (7% – 82%) and jet traverse rate (3000 mm/min – 5000 mm/min) with a MAE of 47 μm, and the hmax with an error < 6%. The predicted geometry of the CP correlates well with the experimental ones, with an average R2 of 0.98 and 0.95 in single- and overlapped- pass erosions.

Thermodynamics in Stochastic Conway’s Game of Life

Cellular automata can simulate many complex physical phenomena using the power of simple rules. The presented methodological platform expresses the concept of programmable matter, of which Newton’s laws of motion are an example. Energy is introduced as the equivalent of the “Game of Life” mass, which can be treated as the first level of approximation. The temperature presence and propagation was calculated for various lattice topologies and boundary conditions, using the Shannon entropy measure. This study provides strong evidence that, despite the principle of mass and energy conservation not being fulfilled, the entropy, mass distribution, and temperature approach thermodynamic equilibrium. In addition, the described cellular automaton system transitions from a positive to a negative temperature, which stabilizes and can be treated as a signature of a system in equilibrium. The system dynamics is presented for a few species of cellular automata competing for maximum presence on a given lattice with different boundary conditions.

A general kinematic approach to the seismic stability assessment of slopes

Most of the current studies concerning slope stability assume a toe failure mechanism, which fails to capture the full complexity of slope collapse. In this study, a more comprehensive approach is developed for analyzing seismic slope stability by defining an instability behavior coefficient that considers different failure patterns, including toe, face, and base failure. The proposed coefficient is integrated with a kinematic method of limit analysis to establish a three-dimensional (3D) collapse mechanism that can describe all possible instability behaviors. The impact of earthquake forces on instability behaviors and slope stability is assessed in a modified pseudodynamic manner, which is capable of accounting for the spatiotemporal feature of seismic acceleration. A horizontal slice method is executed for calculating earthquake-induced work rates, as well as a double integral technique to compute dissipation rates due to soil resistance along the sliding surface and work rates generated by soil weight. By applying the principle of energy conservation, the lower-bound solutions of stability numbers are derived, and a further critical solution can be obtained by the combination of the Marine Predators Algorithm and the Nelder-Mead Simplex Algorithm. The proposed method is confirmed to be accurate and effective through comparisons with previous solutions. In addition, a parametric study reveals the effect of the dynamic characteristics of seismic waves on slope stability and instability behaviors. The general approach developed in this study offers a more comprehensive and accurate way to assess seismic slope stability.

Synchronizing Teaching Resources of Energy Conservation Principle in Mechanical Engineering Courses- Year 2 Updates

The conservation of energy, mass, and momentum are three governing laws of physics that are regularly uttered in teaching engineering courses. Mechanical energies in the form of kinetic and potential forms are the most common forms of energy in dynamics. Fluid flow energies relating to pressure, velocity, elevation, fluid friction, pump, and turbine are covered in fluid dynamics. In thermodynamics course, the first law deals with heat energy and work that can alter internal energy in a system. In all these courses, the conservation of energy states that the amount of energy remains constant, that means that energy is neither created nor destroyed but transferable from one form to another, keeping the total energy same within a fixed domain. Students are initially exposed to energy balance equation in their first Thermodynamics course. In this course, emphasis is placed upon those parameters of specific interest related to energy to this subject. We attempted to tie the concepts of the energy balance equation through 1st Law in thermodynamics to those emphasized in Fluid Mechanics. This was accomplished by taking the students from the starting point of the thermodynamics’ first law for Energy Balance equation to the finished Fluid Mechanics’ Bernoulli’s equation. In the following semester, students were again taken through the process of converting the 1st Law of thermodynamics to Bernoulli’s equation of fluid mechanics. Direct and indirect assessments were then conducted to measure students’ understanding on the energy and its conservation. Through a series of questionnaire and their feedback, Students were found to be more knowledgeable in the conservation of energy through the synchronization of energy balance concepts in these two courses. This presentation is a part of work-in-progress project that we first presented at 2022 WVAS meeting.

Gyroscope oscillation depends on a rotor speed velocity

In engineering, all moving rotating objects exhibit gyroscopic effects resulting from the action of an external torque on a rotating object. Gyroscopic effects are the action of a set of inertial moments and movements of an object around three axes of a three-dimensional Cartesian coordinate system. Moments of inertia are created by centrifugal and Coriolis forces, as well as the moment of change in angular momentum, which is expressed by their kinetic energy. The values of the moments of inertia directly depend on the speed of rotation of the object and its rotation around the axes. A short-term effect of an external load on a running gyroscope with displaced support can be manifested by its oscillations. The physics of gyroscope oscillations is not well explained in publications. This article describes the oscillations of a gyroscope by the action of the external torque which is its potential energy converting into kinetic energy of the inertial torques of the gyroscope. The conversion is carried out by the principle of mechanical energy conservation which is the same as for oscillations of a spring with a load.

Study of the Failure Mechanism of an Integrated Injection-Production String in Thermal Recovery Wells for Heavy Oil

The integrated injection-production string is the core tool used in thermal recovery wells for heavy oil, the mechanical behavior of which is complex due to the coupling effect of downhole temperature and pressure and the load induced by steam huff and puff operations. In this paper, an analysis model that calculates the temperature and pressure field during steam huff and puff operations has been established based on the basic principles of energy conservation and heat transfer. Then, the force distribution and strength check of the integrated injection-production string were analyzed. The fatigue damage of the string was evaluated by considering dynamic loads during the injection process. The corrosion life of the string was predicted. Finally, the failure mechanism of the integrated injection-production string in thermal recovery wells for heavy oil was illustrated. The results showed that the strength of the string and vibration fatigue are not the main causes of failure, but corrosion is the main reason for string failure. The residual strength of the corroded string was greatly reduced, which is the fundamental reason for the failure of the string. This paper is of guiding significance to the optimization of design and safety evaluations of the integrated injection-production string in thermal recovery wells for heavy oil.

Fragment theoretical model of concrete blocks subjected to blast loads

Concrete, a typical engineering construction material, will fracture and fragment when subjected to blast loads. In this study, the blast experiments on concrete blocks were carried out using 30kg of explosive B at different stand-off distances, and the concrete fragments were recovered, sieved, weighed, and counted to obtain information of the fragments in different particle size groups. Moreover, the propagation process of the blast energy was analyzed based on the blast theory, and the deformation energy of the concrete blocks subjected to the blast loads was calculated according to the deformation energy theory. The Griffith fracture theory was employed to estimate the energy dissipation during the fragmentation of the concrete blocks, and the initial kinetic energy of the concrete fragments was determined by combining it with the kinematics theory. Subsequently, a fragment theoretical model was developed based on the principle of energy conservation. The validity of the proposed fragment theoretical model was verified by comparing the statistical data of the blast experiments. The present fragment theoretical model can predict the fragmentation degree of concrete members reasonably and effectively and calculate the particle sizes and quantity of concrete fragments under unknown blast load conditions.

Analytical solutions for thermal effects of suspension bridges based on a surrogate model with longitudinal restraint stiffness

Ambient temperature variation has a significant influence on the deformation of main cables and the internal force of towers of long-span suspension bridges. Currently, the finite element method (FEM) is mainly used for these calculations. This paper intends to present an analytical solution of the thermal effects on suspension bridges. First, three typical temperature patterns are defined. Then, a surrogate model is established by replacing the longitudinal restraint stiffness of the main cable and the tower lateral stiffness with a set of equivalent horizontal springs. The stiffnesses of the suspended cables are formulated according to the energy conservation principle, while the tower lateral stiffnesses are obtained by incorporating the pure bending and Euler buckling solutions, namely considering the effect of the axial force placed on the tower top. Following the force equilibrium conditions, two governing equations are built, which can calculate the variations in the longitudinal displacement of the tower top caused by the temperature variation. After that, some other significant thermal effects, such as the horizontal force of the main cable, the sag of the main cable and the bending moment of the tower bottom, are obtained. Finally, the analytical solution is verified through the field test data of the Tsing Ma Bridge in Hong Kong and the FEM results of four typical examples. The proposed surrogate model offers a quick and easy approach for thermal effect analysis with acceptable accuracy. It is helpful to clarify the mechanical nature of temperature effects to facilitate the preliminary bridge design.

A model of a nonisothermal two‐phase flow of compressible fluids

We introduce a simple model of the time evolution of a binary mixture of compressible fluids including the thermal effects. Despite its apparent simplicity, the model is thermodynamically consistent admitting an entropy balance equation. We introduce a suitable weak formulation of the problem based on a combination of the entropy inequality with the total energy conservation principle. Finally, we show compactness of any bounded family of weak solutions and establish a global existence result.