Digital Simulation Method Research Articles

Biomimetic building facades demonstrate potential to reduce energy consumption for different building typologies in different climate zones.

Greenhouse gas (GHG) emissions leading to anthropogenic global warming continue to be a major issue for societies worldwide. A major opportunity to reduce emissions is to improve building construction, and in particular the effectiveness of building envelope, which leads to a decrease in operational energy consumption. Improving the performance of a building's thermal envelope can substantially reduce energy consumption from heating, ventilation, and air conditioning while maintaining occupant comfort. In previous work, a computational model of a biomimetic building façade design was found to be effective in temperate climates in an office context. Through a case study example based on animal fur and blood perfusion, this paper tests the hypothesis that biomimetic building facades have a broader application in different building typologies across a range of climate zones. Using bioinspiration for innovation opens new ideas and pathways for technological development that traditional engineering design does not provide. This study exemplifies the process in a building façade, integrating a new form of insulation, heating and cooling. Methods of mathematical modelling and digital simulation methods were used to test the energy reduction potential of the biomimetic façade was tested in a set of operational applications (office, school, and aged care) and across different climate zones (tropical, desert, temperate, and cool continental). Results indicated that the biomimetic façade has potential to reduce energy consumption for all building applications, with the greatest benefit shown in residential aged care (67.1% reduction). Similarly, the biomimetic building façade showed potential to reduce operational services energy consumption in all climate zones, with the greatest energy reductions achieved in the tropical (55.4% reduction) and humid continental climates (55.1% reduction). Through these results the hypothesis was confirmed suggesting that facades engineered to mimic biological functions and processes can improve substantially decrease building operational energy consumption and can be applied in different building classifications and different climate zones. These results would significantly decrease operational greenhouse gas emissions over the lifetime of a building and provide substantial savings in energy bills. Such facades can contribute to the further reduction in greenhouse gas emissions in a broad range of contexts in the built environment and other areas of technology and design. The flexibility and adaptability of biomimetic facades exemplify how biological strategies and characteristics can augment and improve performance in different environments, since the organisms that inspire innovation are already well-adapted to the conditions on earth. This study also exemplified a method by which other biomimetic building envelope features may be assessed. Further work is suggested to assess economic viability and constructability of the proposed facades.Graphic abstract

Digital Simulation as a Design Method of Artificial Lighting for Prayer Rooms

This article aims to describe the results of the lighting design for the prayer room using a simulation method to answer the needs of function and ambience. In general, the lighting design for prayer rooms does not use an integrated approach. A common problem faced by prayer rooms, especially churches and chapels, is too glaring or too dim in some cases. The results of the community service activities in the form of lighting planning for the Church of Santa Theresia Sedayu and Chapel of SMA de Britto with the digital simulation method expect to provide an overview of designing lighting with a more measured method that can meet the needs of the ambience. Lighting simulation in both cases uses DIALux Evo software. The simulation result shows that the lighting design meets lighting standards and is able to provide a sacred atmosphere. Concerning the study, solving lighting problems with the digital simulation as the method is more scalable and can meet the ambience needs. Field measurements of the lighting design results can be carried out in the future to measure the simulation's level of achievement and validation.

Accurate Clamping Method of Multipoint Flexible Fixture for Large Complex Surface

In the field of aviation and astronautics, large complex surface parts such as aircraft cabin cover are complex, varying in model, and produced in small batch. In order to reduce fixture cost and improve production efficiency, a variable multipoint and multi-DOF supporting fixture is designed. The coordinate system of the complex structure fixture is defined, and the kinematics of the multibody structures driven by air cylinders are modeled according to the topological principle. With the help of this data structure, fast and optimal search for clamping state can be realized. With the dichotomy method, the driving amount of the electric cylinder of the suction cups and the two rotation angles of two rotation axes at the end of the linkages are solved accurately. Based on the digital twin simulation method, the precise clamping motion of flexible fixture is calculated for an aircraft cockpit cover with a software developed by the authors in C++ language on the Visual studio platform. The distance between the clamping point and the surface was verified with a laser tracker. Finally, the practical experiment of a real cockpit cover clamping proves the practicability and effectiveness of the proposed method.

Simulating hadronic physics on noisy intermediate-scale quantum devices using basis light-front quantization

The analogy between quantum chemistry and light-front quantum field theory, first noted by Wilson, serves as motivation to develop light-front quantum simulation of quantum field theory. We demonstrate how calculations of hadron structure can be performed on noisy intermediate-scale quantum devices within the basis light-front quantization (BLFQ) framework. Within BLFQ, relativistic quantum field theories take a form that permits direct application of methods for digital quantum simulation of quantum chemistry, which can be readily scaled into the quantum advantage regime. We calculate the light-front wave functions of pions using an effective light-front Hamiltonian in a basis representation on a current quantum processor. We use the variational quantum eigensolver to find the ground-state energy and the corresponding wave function, which is subsequently used to calculate pion mass radius, decay constant, elastic form factor, and charge radius.

A High Precision Modeling Technology of Material Surface Microtopography and Its Influence on Interface Mechanical Properties.

In order to accurately and effectively obtain the contact performance of the mating surface under the material surface topography characteristics, a numerical simulation method of rough surface based on the real topography characteristics and a multi-scale hierarchical algorithm of contact performance is studied in this paper. Firstly, the surface topography information of materials processed by different methods was obtained and characterized by a measuring equipment; Secondly, a non-Gaussian model considering kurtosis and skewness was established by Johnson transform based on Gaussian theory, and a rough surface digital simulation method based on real surface topography was formed; Thirdly, a multi-scale hierarchical algorithm is given to calculate the contact performance of different mating surfaces; Finally, taking the aeroengine rotor as the object, the non-Gaussian simulation method was used to simulate the mating surfaces with different topographies, and the multi-scale hierarchical algorithm was used to calculate the contact performance of different mating surfaces. Analysis results showed that the normal contact stiffness and elastic–plastic contact area between the mating surfaces of assembly 1 and assembly 2 are quite different, which further verifies the feasibility of the method. The contents of this paper allow to perform the fast and effective calculation of the mechanical properties of the mating surface, and provide a certain analysis basis for improving the surface microtopography characteristics of materials and the product performance.

A new intelligent and data-driven product quality control system of industrial valve manufacturing process in CPS

The development of intelligent and data-driven product quality control system are emerging as key engineering technologies for industrial manufacturing process. And many studies have been made to investigate the application of quality control of industrial valve manufacturing process in cyber–physical systems (CPS). The purpose of this article is to provide a quality control and management system by using the modern electronics technology, information technology and network technology. Firstly, we propose an intelligent and data-driven framework model of product quality based on the advanced technology of digital twin (DT) and simulation methods for CPS. Secondly, we emphasize the manufacturing enterprise should hold a data accumulation, and give some useful advises on how to carry out a successful quality analysis system of industrial valve manufacturing process in CPS. Then, as a case, the intelligent method of BP neural network is constructed according to lots of quality characteristics (QCs) of the mechanical and electrical product of industrial valve, and the BP network is trained by using many quality failures of manufacturing process. Finally, the results show that the new quality control system has good accuracy and practicability by the practical example.

Seepage Mechanism of Tight Sandstone Reservoir Based on Digital Core Simulation Method

Recently, tight sandstone oil has played an increasingly important role in the energy strategies of countries around the world. However, the understanding of a microscopic mechanism is still not clear enough, which has been affecting the improvement of the recovery of tight sandstone oil. In this article, a digital core model was established to simulate the pore network of a physical core with CT scan and difference equations were verified by Fourier counting. Then, a combination of orthogonal tests and cubic digital cores was used to experimentally investigate various parameters including pressure, length, permeability, viscosity, and time. By combining the physical experiments with the digital core methods, it can be observed that the state of the micro-crack affects the conductivity of the core, which may be the decisive reason for changing the pressure gradient. The orthogonal test showed that the sensitivity of the parameters was pressure, length, permeability, time, and viscosity in order. The results of the numerical simulations showed that this method can reveal the seepage mechanism of a tight sandstone reservoir, greatly shortening the experimental time and improving flexibility.

Theory of Trotter Error with Commutator Scaling

The Lie-Trotter formula, together with its higher-order generalizations, provides a direct approach to decomposing the exponential of a sum of operators. Despite significant effort, the error scaling of such product formulas remains poorly understood. We develop a theory of Trotter error that overcomes the limitations of prior approaches based on truncating the Baker-Campbell-Hausdorff expansion. Our analysis directly exploits the commutativity of operator summands, producing tighter error bounds for both real- and imaginary-time evolutions. Whereas previous work achieves similar goals for systems with geometric locality or Lie-algebraic structure, our approach holds in general. We give a host of improved algorithms for digital quantum simulation and quantum Monte Carlo methods, including simulations of second-quantized plane-wave electronic structure, $k$-local Hamiltonians, rapidly decaying power-law interactions, clustered Hamiltonians, the transverse field Ising model, and quantum ferromagnets, nearly matching or even outperforming the best previous results. We obtain further speedups using the fact that product formulas can preserve the locality of the simulated system. Specifically, we show that local observables can be simulated with complexity independent of the system size for power-law interacting systems, which implies a Lieb-Robinson bound as a byproduct. Our analysis reproduces known tight bounds for first- and second-order formulas. Our higher-order bound overestimates the complexity of simulating a one-dimensional Heisenberg model with an even-odd ordering of terms by only a factor of $5$, and is close to tight for power-law interactions and other orderings of terms. This suggests that our theory can accurately characterize Trotter error in terms of both asymptotic scaling and constant prefactor.

Catalytic ErevCrev′ mechanism at cylindrical wire electrodes: Theory of controlled-potential transients assuming DO = DR, and highly accurate computation of chronoamperograms and cyclic voltammograms

There have been surprisingly few theoretical studies devoted to large-signal controlled-potential experiments for the catalytic ErevCrev′ mechanism (containing a reversible charge transfer and a reversible homogeneous reaction) at cylindrical wire electrodes, and their results were partially doubtful. To fill this gap, a general theory is developed, applicable to any such experiments, under the assumption of equal diffusion coefficients of the redox species (DO = DR) and a pseudo-first order homogeneous reaction. Based on the theory, numerical procedures are elaborated and implemented in C++, for computing special functions related to chronoamperometric and cyclic voltammetric currents. The procedures are fairly fast and highly accurate. In the case of chronoamperometry they provide results with moduli of relative errors at the level of 10−18 or smaller. Similar accuracy is achieved for cyclic voltammograms, as long as the current is not too close to zero, or equal zero. In the latter cases the errors may increase considerably, but relative error moduli not bigger than about 10−13 were observed. The procedures can be useful for validating digital simulation methods for electrochemistry, and for the analysis of experimental data. They are freely available.

3D-моделирование эффекта гидроизостазии с близкой к реальной конфигурацией поверхности Мохо для Охотского моря

Interrelation between global sea level changes during Glacial–Interglacial periods and Earth surface deformations is studied using digital simulation methods. During Earth surface deformations, the deformation amplitude is expected to depend on variable thickness of the upper lithospheric layer. 3D modeling allows to take into account thickness variation of the lithospheric layer. In this work, 3D modeling of hydroisostasy under marine transgression similar to Interglacial ones for the Sea of Okhotsk has been made with creating a mesh on the base close to real bathimetry of the Sea of Okhotsk and Moho surface configuration. Simulation has been done by finite element method by Elmer software suite. As a result, relation between Moho surface configuration and Earth surface deformation was found.

DEVELOPMENT OF A SYSTEM OF AUTOMATIC MOBILE CONTROL OF THE DISTILLATION PROCESS

Subject. System of automatic mobile control of distillation process. Objective. Improving the productivity and energy efficiency of the distillation process by developing an automatic control system that provides mobile control effects on the process, as well as the study of transients in the developed system during major disturbances. Tasks. Development of a system of automatic mobile control of the distillation process, calculation of transients in the developed system, definition and evaluation of quality control indicators. Methods. Methods of simulation digital modeling of automatic control system operation. Results. A system of automatic control of the distillation process has been developed, which provides for discrete and continuous mobile control actions. Discrete effects are changes in the point of introduction of feed into the column; continuous – in changing the ratio of the flow rates of feed flows supplied to the upper and lower parts of the installation. Traditional control effects are also used by changing the heat carrier flow rate in the cube evaporator and irrigation. Optimal traditional and mobile control effects are calculated by the computing control device according to the normalized criterion using a nonlinear predictive model and are realized by influencing the actuators on the supply lines of feed flows, irrigation in the column and the heat carrier in the evaporator. The system involves the use of an adequate mathematical model, for which its periodic identification is performed and the process is monitored by additional measurement of the temperature profile of the column, temperature and pressure on the control plate. In order to maintain the material balance in the liquid and steam phases, it is planned to stabilize the pressure at the top of the column, the levels in the distillate and the cubic product receivers by changing the flow rates, of refrigerant to the condenser, distillate and cubic product. Using the example of a distillation column for separating a methanol-water mixture, the operability of the proposed automatic mobile control system is studied by digital simulation methods. The disturbances consisted of changes in the flow rate, composition, and temperature of the feed. Conclusions. It is proved that the use of the developed system allows to increase the technical and economic indicators of the distillation process and to improve the quality of management. The results can be used in the chemical, petrochemical, oil refining, food industries to control and optimize the processes of binary, multicomponent distillation.

The Chemical Reactivity Study of Organotin(IV) 4-aminobenzoates Using Cyclic Voltammetry and Antioxidant Activity Test by the DPPH Method

Abstract: Chemical reactivity studies of the organotin(IV) carboxylates diphenyltin(IV) di-4-amino-benzoate (1) and triphenyltin(IV) 4-aminobenzoate (2) were conducted using cyclic voltammetry. Then, their antioxidant activities were tested by the 2,2-diphenyl-1-picrylshydrazyl (DPPH) method. Cyclic voltammetry was used to determine the kinetic constants of compounds 1 and 2 for the forward chemical reaction (kf). The constant values of the chemical reaction rate of 1 and 2 on cyclic voltammogram by experiment were obtained by comparing with the values from digital simulation methods obtained using Polar software 5.8.3. The results demonstrated that the constant value of the rate of the subsequent chemical reaction is a function of the rate of its potential (slope = kf/i); that is, 6.481 and 6.069 1/V for 1 and 2, respectively. The type of chemical reaction mechanism that occurs around the surface of the working electrode follows reaction mechanism of electrochemical reaction is quasi reversible and chemical reaction is irreversible (EqCi). The antioxidant activities of compounds 1 and 2 produced IC50 values of 5.91 and 12.57 ig/mL, respectively. These results indicate that both compounds are active as antioxidants. However, their antioxidant activities were lower than that of ascorbic acid, which has an IC50 value of 0.66 ig/mL.

Real-time models of pulsed reflectance profiles of 3D objects in a monostatic laser location system

The cluster structure of the distance profile of an anthropogenic 3D object in a monostatic laser location system is investigated using a digital simulation method. A physically valid method for decomposing the pulsed reflectance profile of a target into continuous and discontinuous components is proposed. A real-time model for the structural components of the temporal profile of the pulsed reflectance profile of the object is realized based on a finite combination of standard pulses. The results of the identification of the parameters of a finite combination of standard pulses using a modified expectation-maximization algorithm are presented.

Lithium–Oxygen Power Source: the Influence of Positive Electrode Thickness on the Overall Discharge Characteristics

Characteristic feature of the discharge process of lithium–oxygen battery cathode with non-aqueous electrolyte is the blockade of pores in the positive electrode by lithium peroxide (Li2O2), an insoluble in the electrolyte and non-conductive substance. Lithium peroxide blocks cathode pores and thus hinders the oxygen entering therein. This complicates, in its turn, further behavior of the reaction. The goal of this work is to understand the following problems: (1) why is the acceptable thickness of the positive-electrode active layer extremely low, and (2) what is the reason of the lowering of specific capacity with the increasing of the active layer thickness. The main properties of the lithium—oxygen battery discharge—the current density, discharge time, specific capacity and the constant of oxygen consumption k*—were calculated using a digital simulation method. It was shown that the necessity of usage of low discharge current density is caused by the small thickness of the cathode region adjacent to the boundary with gaseous phase, in which the formation of Li2O2 occurs. An increase in the cathode thickness induces a decrease in the current density, which, in its turn, leads to increase in parameter k and decrease in the discharge capacity.

Application of passive energy-saving technology for building planning in urban power supply system

In order to overcome the energy consumption problem of energy-saving technology in traditional urban power supply system, a new passive energy-saving technology for building planning is proposed. Based on the Ecotect tool, the best orientation is obtained, the digital simulation method is introduced and combined with the characteristics of the building itself to carry out the digital simulation, so as to realise the design of photovoltaic array. The output cables of solar cell module arrays are connected separately, so that each connection has a certain order, thus improving the fault tolerance of the system. The experimental results show that the proposed method has a high photovoltaic power generation capacity of 1726 kW and a low annual energy consumption of about 15 Wh/m². It is proved that passive energy-saving technology has better performance and higher reliability in power supply system.

Recurrent Graph Convolutional Network-Based Multi-Task Transient Stability Assessment Framework in Power System

Reliable online transient stability assessment (TSA) is fundamentally required for power system operation security. Compared with time-costly classical digital simulation methods, data-driven deep learning (DL) methods provide a promising technique to build a TSA model. However, general DL models show poor adaptability to the variation of power system topology. In this paper, we propose a new graph-based framework, which is termed as recurrent graph convolutional network based multi-task TSA (RGCN-MT-TSA). Both the graph convolutional network (GCN) and the long short-term memory (LSTM) unit are aggregated to form the recurrent graph convolutional network (RGCN), where the GCN explicitly integrate the bus (node) states with the topological characteristics while the LSTM subsequently captures the temporal features. We also propose a multi-task learning (MTL) scheme, which provides joint training of stability classification (Task-1) as well as critical generator identification (Task-2) in the framework, and accelerate the process with parallel computing. Test results on IEEE 39 Bus system and IEEE 300 Bus system indicate the superiority of the proposed scheme over existing models, as well as its robustness under various scenarios.

Estimation of the condition and approaches to the rehabilitation of the geological environment disordered as a result of construction and anthropogenic activities

Introduction. The paper considers the issue of estimation of disordered areas as a result of construction and anthropogenic activities and suggests strategies for solving this problem by the example of the Samara region. Materials and methods. The article applies the generally accepted methods and research conducted by employees of Samara State Technical University. The sources of initial data are reports of state authorities. The subjects of the study are engineering-geological environmental elements, industrial facilities, polluting components and surface and Groundwater bodies. Results. The paper proposes a ranking-system for estimation of disorder areas and classification by areas of economic activity. The article provides the classification of the impact of technological losses of enterprises, the activity of which leads to the disruption of the geological environment. A resource and ecological approach for technogenic deposits of various substances and a strategy for their use and subsequent environmental restoration are proposed. The research presents the results of technogenic deposit 3D simulation as well as approaches to their interpretation. Conclusions. The developed approach and methodological basis for the analysis of the geological system, including the technogenic lens allow evaluating, analyzing, and predicting the migration of human-made lenses formed as a result of construction and economic activity. A resource-based and ecological approach was used for the simultaneous collection of pollutant fluids and the rehabilitation of the geological environment. The article recommends to use 3D digital simulation methods to increase the efficiency of research and predict the number of substances in the depths. The methods apply to human-made deposits, subject to the determination of the ambiance filtration characteristics by water and fluid. It is proposed to use biodegradable surfactants as a method of geological environment rehabilitation. This choice is stipulated by the fact that surfactants allow “washing” the rocks without increasing the burden on the environment. An alternative method is proposed for predicting fluid migration due to the description of the geosystem as a system of forced oscillations. The method allows predicting the periods of the most efficient oil production and designated engineering protection methods.

General methods for digital quantum simulation of gauge theories

A general scheme is presented for simulating gauge theories, with matter fields, on a digital quantum computer. A Trotterized time-evolution operator that respects gauge symmetry is constructed, and a procedure for obtaining time-separated, gauge-invariant operators is detailed. We demonstrate the procedure on small lattices, including the simulation of a 2+1D non-Abelian gauge theory.

Quantum algorithm for simulating an experiment: Light interference from single ions and their mirror images

We widen the range of applications for quantum computing by introducing digital quantum simulation methods for coherent light-matter interactions: We simulate an experiment where the emitted light from a single ion was interfering with its mirror image [Eschner et. al., Nature 431, 495 (2001)]. Using the quantum simulation software q1tsim we accurately reproduce the interference pattern which had been observed experimentally and also show the effect of the mirror position on the spontaneous emission rate of the ion. In order to minimize the number of required qubits we implement a qubit-reinitialization technique. We show that a digital quantum simulation of complex experiments in atomic and quantum physics is feasible with no more than seven qubits, a setting which is well within reach for advanced quantum computing platforms.

Electrochemistry of Br−/Br2 Redox Couple in Acetonitrile, Methanol and Mix Media of Acetonitrile–Methanol: An Insight into Redox Behavior of Bromide on Platinum (Pt) and Gold (Au) Electrode

Abstract Electro-oxidation of Br− on platinum and gold electrode was studied in acetonitrile, methanol and mix media of acetonitrile–methanol. The mechanism of Br− oxidation in these media was investigated using CV, Semi Integration Cyclic Voltammetry, and Digital Simulation technique. Since, Br− oxidation mechanism on platinum involves the formation of Br3 − as intermediate, therefore, Kstab for Br3 − formation in the mixed media was estimated using digital simulation, Nelson and Iwamoto method. Redox mechanism of Br− and Br2 on gold (Au) electrode was also investigated in protic solvent such as H2O, methanol, ethanol, 1-butanol, and formic acid. It was ascertained that Br− oxidation on gold (Au) electrode in these above protic solvents involve [AuBr2]− intermediate rather than Br3 −.