Simulation Engine Research Articles

Energy efficiency potential determination for an oil treatment and stabilization unit at the field

Relevance. The desire to increase the energy efficiency of industrial enterprises and reduce greenhouse gas emissions from their activities. Reducing specific energy consumption at large oil refineries and petrochemical plants is not new and is quite widely used. Dozens of monographs and thousands of articles are devoted to these areas. But it should be taken into account that in the oil refining industry, all crude oil, even that which does not reach the refinery, necessarily passes through oil preparation and stabilization units at the fields. Therefore, in order to create energy-efficient and environmentally friendly processes throughout the entire oil refining chain, it is necessary to increase the energy efficiency of the oil preparation and stabilization units located at the fields. There are very few research works on thermal energy integration of oil preparation and stabilization units. Aim. Determination of target design and energy values for an energy-efficient retrofit project of the heat exchange network for the surveyed oil preparation and stabilization units and of its energy efficiency potential. Methods. Pinch analysis methods are used to determine the target values of an energy-efficient retrofit project. Mathematical modeling of heat exchange processes in the heat exchange network and economic analysis were performed using the Pinch 2.02 software; the Aspen HYSYS software package was used to create a simulation engineering model of the oil preparation and stabilization units. Results. When determining the target values of the heat exchange network retrofit project, the cost of energy and heat exchange equipment, the cost of collectors for splitting process streams, and technical restrictions on the placement of heat exchanger sections were taken into account. The inclusion of fuel gas in the process stream table has allowed the definition of target parameters for the optimal unit heat exchange network design to evolve. In the process of evolution of target values, the energy efficiency potential of the surveyed oil preparation and stabilization units was determined, which shows the possibility of reducing specific energy consumption by 77%. Upon implementation of the heat exchange network retrofit project and achievement of target parameters, the following economic results will be obtained: IRR=42%, NPV=7425780 USD, DPP 4 years. Also, CO2 emissions can be reduced by 30 thousand tons per year. It should be noted that the evolution of target designation and all target values for the reconstruction project were obtained before the implementation of the heat exchange network oil preparation and stabilization units project itself.

A SAC-Bi-RRT Two-Layer Real-Time Motion Planning Approach for Robot Assembly Tasks in Unstructured Environments

Due to the uncertainty and complexity of the assembly process, the trajectory planning of a robot needs to consider the real-time obstacle avoidance problem when it completes the assembly in the unstructured workspace. To realize the safe assembly of assembly robots in dynamic and complex environments, a dynamic obstacle avoidance trajectory planning method for robots combining traditional planning algorithms and deep reinforcement learning algorithms is proposed to improve the robot’s agent and obstacle avoidance ability in dynamic and complex environments. The Bidirectional Rapidly-exploring Random Tree (Bi-RRT) method is utilized as a global planner to plan the global optimal path quickly; considering the real-time nature of the assembly process, the Soft Actor-Critic (SAC) is used as a local obstacle avoider to avoid obstacles more accurately and to find the nearest node generated by the Bi-RRT during the planning process, which is regarded as the goal during the local obstacle avoidance to reduce the model’s complexity. By training and testing in the simulation engine and comparing with SAC, DDPG and DQN algorithms, the method can avoid obstacles in dynamic and complex environments more efficiently, which verifies that the proposed hybrid method can accomplish the high-precision planning task with a high success rate.

Study the Effect of Exhaust Manifold Diameter on the Output Performance of a Four-Cylinder Spark Ignition Engine

As modern engine technology has evolved, optimizing engine performance has become a key research focus for the industry in the face of increasingly stringent environmental regulations and growing demand for energy efficiency. The diameter of the exhaust manifold plays a key role in determining engine performance. This study utilized GT-POWER software to develop an engine simulation model aimed at investigating the effects of different exhaust manifold diameters on engine power, torque, and fuel consumption. The results demonstrated that increasing the exhaust manifold diameter within a specified range significantly reduced fuel consumption at lower speeds, with minimal impact on power and torque. However, at moderate to high speeds, enlarging the exhaust manifold diameter led to a significant increase in power output, an increase in peak torque, and a decrease in fuel consumption, resulting in the shift of peak torque and minimum fuel consumption to higher speeds. These findings provide valuable insights for optimizing engine exhaust manifold design.

Enhancing CZTS solar cell performance via back surface field in simulation engineering

Enhancing CZTS solar cell performance via back surface field in simulation engineering

Application of 3D Virtual Digital Visualization Technology in the Simulation and Modeling of Cross-Sea Network Engineering

This paper analyzes the importance of cross-sea interconnection projects and delves into the application of 3D virtual digital visualization technology in the simulation of these projects. The system employs OpenGL technology to render 3D images and supports environmental configuration through dynamic link libraries. The internal design of the system is clear, featuring functionalities such as multi-scene dynamic focusing, multi-data port linkage, BIM information display, event tracing, and process simulation. Compared with traditional construction techniques, 3D virtual visualization technology exhibits significant advantages in graphic rendering, scheme selection, collaboration, and construction methods. The research presented in this paper provides valuable references for optimizing cross-sea interconnection projects and other major infrastructure constructions, demonstrating the immense potential of 3D virtual visualization technology in enhancing construction efficiency and reliability.

Application of physics-informed neural networks (PINNs) solution to coupled thermal and hydraulic processes in silty sands

The accurate modeling of water and heat transport in soils is crucial for both geo-environmental and geothermal engineering. Traditional modeling methods are problematic because they require well-defined boundaries and initial conditions. Recently, physics-informed neural networks (PINNs), which incorporate partial differential equations (PDEs) to solve forward and inverse problems, have attracted increasing attention in machine learning research. In this study, we applied PINNs to tackle hydraulic and thermal transport coupling forward problems in silty sands. A fully connected deep neural network was utilized for training. This neural network model leverages automatic differentiation to apply the governing equations as constraints, based on the mathematical approximations established by the neural network itself. We conducted forward problems and compared the solutions derived from PINNs with those from Finite Element Method (FEM) simulations. The forward problem results demonstrate the PINNs model’s capability in predicting hydraulic transport, heat transport, and thermal–hydraulic coupling in silty sands under various boundary conditions. The PINNs exhibited great performance in simulating the thermal–hydraulic coupling problem. The accuracy of the PINNs solutions shows its potential for simulation in geotechnical engineering.

Heritage BIM and performance simulation interoperability: methodological insights from representative case studies in Cyprus and Italy

ABSTRACT BIM advances for the AEC industry's digital transformation agenda is hindered by poor software interoperability with Building Performance Simulation (BPS) tools. In an effort to identify the causes of this barrier and address possible directions to overcoming challenges, this paper presents two semi-automatic BIM to BPS workflows for heritage buildings, following the employment of the gbXML and the IFC exchange schemas respectively. Each workflow encompasses the integration of dynamic energy simulation data, as well as the conversion of morphologically complex geometries from BIM to the streamlined requirements of the respective numerical simulation engines. These parallel workflows are implemented and assessed through their application for the energy and environmental improvement of two heritage buildings, located in Cyprus and Italy. These buildings are studied as specific cases to drive the development of an energy simulation-based Heritage BIM (HBIM) workflow presented here. The findings of this research offer methodological insights into BIM data integration strategies and best practices in modeling for the schema-based workflows presented. Finally, the paper discusses impending methodological framework improvements and argues for the impact of specific roles and expertize on the process, in an effort to establish an adequate interoperability maturity level of BIM models in said operations.

Free Energy of Membrane Pore Formation and Stability from Molecular Dynamics Simulations.

Understanding the molecular mechanisms of pore formation is crucial for elucidating fundamental biological processes and developing therapeutic strategies, such as the design of drug delivery systems and antimicrobial agents. Although experimental methods can provide valuable information, they often lack the temporal and spatial resolution necessary to fully capture the dynamic stages of pore formation. In this study, we present two novel collective variables (CVs) designed to characterize membrane pore behavior, particularly its energetics, through molecular dynamics (MD) simulations. The first CV─termed Full-Path─effectively tracks both the nucleation and expansion phases of pore formation. The second CV─called Rapid─is tailored to accurately assess pore expansion in the limit of large pores, providing quick and reliable method for evaluating membrane line tension under various conditions. Our results clearly demonstrate that the line tension predictions from both our CVs are in excellent agreement. Moreover, these predictions align qualitatively with available experimental data. Specifically, they reflect higher line tension of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) membranes containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phospho-l-serine (POPS) lipids compared to pure POPC, the decrease in line tension of POPC vesicles as the 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoglycerol (POPG) content increases, and higher line tension when ionic concentration is increased. Notably, these experimental trends are accurately captured only by the all-atom CHARMM36 and prosECCo75 force fields. In contrast, the all-atom Slipids force field, along with the coarse-grained Martini 2.2, Martini 2.2 polarizable, and Martini 3 models, show varying degrees of agreement with experiments. Our developed CVs can be adapted to various MD simulation engines for studying pore formation, with potential implications in membrane biophysics. They are also applicable to simulations involving external agents, offering an efficient alternative to existing methodologies.

Orientation effect and locational variation in elastic-plastic compressive properties of bovine cortical bone.

Bone is a highly heterogeneous and anisotropic material with a hierarchical structure. The effect of diaphysis locations and directions of loading on elastic-plastic compressive properties of bovine femoral cortical bone was examined in this study. The impact of location and loading directions on elastic-plastic compressive properties of cortical bone was found to be statistically insignificant in this study. The variances of most of the compressive properties were also observed to be location and directionality independent except for the locational differences in modulus of resilience (distal to central for longitudinal loading) and plastic work (central to distal for transverse loading) as well as differences in variances of the modulus of resilience and elastic modulus values for two directions of loading. The micro-mechanisms of cortical bone failure for longitudinal and transverse directions of loading were considered to be responsible for the difference in variances in the later properties values as well as for the maximum and minimum coefficient of variation (CV) obtained for compressive properties in two directions of loading. The representative cubical volume at the tested hierarchical level contained all unique microstructural features of the plexiform bone and therefore produced the homogeneous and isotropic elastic-plastic compressive properties of cortical bone. It is expected that the outcome of this study may be helpful in the area of bone tissue engineering and finite element simulation of cortical bone.

Harnessing LPS Metrics for Smarter Resource Allocation and Project Control through Gamification

Question: What is the significance of Last Planner System® (LPS®) metrics in capacity planning and project outcomes? Purpose: This study highlights the vital role of LPS metrics in optimizing resource allocation for improved capacity planning, lookahead scheduling, and waste reduction. Additionally, it showcases the efficacy of simulation-based serious games as an engaging and instructive pedagogical method. Research Method: Simulation-based serious game developed using a discrete-event simulation engine and a user-friendly interface. Findings: This study delineates the differences between individuals exposed to LPS metrics during capacity planning and those without such exposure, and the differences between individuals with and without prior LPS knowledge. Limitations: It’s essential to acknowledge that simulating real project conditions in a game necessitates certain assumptions. Implications: This game can evolve into a valuable educational tool for assessing users’ capacity planning and metric analysis competencies. Multiple versions could also be developed to assess diverse skills vital to project planning and control. Value for practitioners: This paper not only highlights the importance of LPS metrics in capacity and lookahead planning, but also sheds light on the availability of educational and evaluative games. Such games can be embraced by organizations to enhance their current educational and training practices. Keywords: LPS® metrics, capacity planning, resource allocation, serious games Paper type: Full Paper

A versatile deformation-oriented criterion for optimisation-based backcalculation of the pavement moduli and thickness

ABSTRACT Optimisation-based backcalculation problem in order to extract pavement moduli and thickness have been drastically developed nowadays. It not only serves a feasible cost-effective technique but also shapes a special class of non-destructive tests. The historical course of evolution in this field has caused the emergence of a variety of detector criteria. In this regard, the conventional deformation-based variation criterion (CVC), calculates the discrepancies between the deflection of the pavement surface and the deflection computed by the numerical simulation engine. Indeed, the CVC suffers from the lack of knowledge in relevance with the deformation pattern of the pavement surface. To tackle this dim spot, the present research work aims to propose a versatile criterion called ‘deformation-pattern-based variation criterion (PVC)’ to estimate both moduli and thickness of pavement using the IAS metaheuristic optimisation algorithm. Remarkably, the proposed criterion, PVC, not only efforts to find the deflection points of the pavement surface but also strives to adjust a consistent deformation with the variation pattern of the pavement surface. To investigate the efficiency and robustness of the proposed technique, it is implemented on a hypothetical three-layer pavement and a four-layer field pavement. The obtained results confirmed the outperforming of the PVC compared with the CVC in terms of the pavement modulus and thickness estimation.

THE VOLUMETRIC EFFICIENCY OF A SINGLE-CYLINDER SPARK-IGNITION ENGINE AS AFFECTED BY AIR INTAKE TEMPERATURE AND HUMIDITY

Nowadays, there are an increasing demand for energy efficiency and emission reduction by the internal combustion engine. It can be achieved by improving the volumetric efficiency of spark ignition engine. The air intake temperature and humidity give an impact to the volumetric efficiency. Thus, the goal of this study is to investigate the impacts of air intake temperature and humidity on the volumetric efficiency of a single cylinder spark ignition engine. This study was facilitated using Altair HyperStudy. It was executed by full factorial design of experiments (DOE). The effects of engine speed, air intake temperature, and humidity towards the volumetric efficiency was assessed based on one-dimensional engine simulation. The ANOVA analysis showed a positive correlation between engine speed and volumetric efficiency. There is a negative effect found for the air intake temperature. However, a negligible impact of humidity obtained in this study. The optimal configuration for achieving a maximum volumetric efficiency of 0.97 was identified at 4500 RPM, 26 degrees Celsius, and 68.0% humidity. It is suggested by the results that while engine speed has a significant impact on volumetric efficiency, temperature and humidity also play important roles in optimizing engine performance. These insights are valuable for designing and operating more efficient and environmentally friendly engines.

Numerical simulation of a DISI engine with a reduced chemical kinetic mechanism for gasoline–ethanol blends

Numerical simulation of a DISI engine with a reduced chemical kinetic mechanism for gasoline–ethanol blends

Integrative physiology-coupled pilot-centered flight simulation

Maintaining the pilot’s physiological performance envelope within the limits of human capabilities may be crucial for avoiding hazardous physiological episodes in fighter aircraft that compromise safety. The main physiological episode of interest is impaired pilot respiration, better known as hypoxia, caused by a high fraction of inspired oxygen (FiO2) at high altitudes and variation in accelerative gravitational forces (g-forces). This research focuses on coupling FlightGear and Pulse Physiology Engine (Pulse) simulations to recreate and understand hypoxic events related to a combination of high g-forces and high-FiO2. By coupling interactive simulations based on FlightGear and Pulse, hypoxia was recreated from two scenarios: simulated accelerative atelectasis, achieved by using high g-forces output from FlightGear with a modified Pulse tension pneumothorax scenario, and the combination of high g-forces and high-FiO2, based on a prototype OBOGS simulation. Each scenario resulted in hypoxic events after executing three consecutive simulations, validated by the ratio mismatch of pulmonary ventilation ([Formula: see text]) and perfusion ([Formula: see text]) rates, [Formula: see text], due to a reduction in ventilation. Eventually, a detailed atelectasis simulation founded on multi-physics finite elements (FE) is planned in future work, where real-time efficiency is feasible through a deep neural network implementation trained on FE experiments. Using neural networks based on biometrics and pre-existing health conditions, if any, will result in the development of a predictive analytics model to determine whether pilots are susceptible to hypoxia prior to flight.

An OpenSees Surrogate Constitutive Model for High-Damping Rubber Based on Machine Learning.

The complex mechanical properties of high-damping rubber (HDR), a commonly used seismic isolation material in buildings and bridges, present a significant challenge in civil engineering. In a previous study, the authors proposed an HDR constitutive model that combines a Gated Recurrent Unit (GRU) and an attention mechanism, offering novel insights into the mechanical properties of HDR. The constitutive model was simplified first to facilitate the deployment of the proposed constitutive model within the finite element analysis environment. Then, the simplified constitutive model was converted into a uniaxial material format suitable for use within the open system for earthquake engineering simulation (OpenSees). In OpenSees, the uniaxial material was named HDRGA material, and the code for the HDRGA material header and source files was written. Finally, an HDR surrogate constitutive model was developed in OpenSees. To validate the precision of the HDRGA material in characterizing the mechanical attributes of HDR, a two-node model and a single-pier model were devised, and their accuracy was verified through a comparative analysis of test results and nonlinear time history calculation results, respectively. The results demonstrate that the developed HDRGA material is capable of performing well under earthquakes.

Semirational Design of a UDP-Glycosyltransferase from Nicotiana tomentosiformis for Efficient Biosynthesis of Rebaudioside M2.

Rebaudioside M2 (RebM2) is characterized as 13-[(2-O-β-d-glucopyranosyl-3-O-β-d-glucopyranosyl-β-d-glucopyranosyl)oxy] ent-kaur-16-en-19-oic acid-[(2-O-β-d-glucopyranosyl-6-O-β-d-glucopyranosyl-β-d-glucopyranosyl) ester], an isomer of rebaudioside M with a 1 → 6 sugar linkage. The product was found in the biotransformation of rebaudioside D (RebD) catalyzed by a glycosyltransferase from Nicotiana tomentosiformis (NtUGT). Herein, guided by consensus engineering and molecular dynamics simulations, a variant NtUGTF72L/L123P/L157P with enhanced activity and thermostability was obtained. It exhibits a strikingly reduced Km (22.47 mM to 0.15 mM) toward RebD, and the catalytic efficiency was over 5000-fold higher than that of the wildtype. When an Arabidopsis sucrose synthase AtSuSy was used for UDP-glucose recycling, NtUGTF72L/L123P/L157P effectively converted 80 g/L RebD to 90.14 g/L RebM2. In a one-pot three-enzyme reaction involving an engineered glycosyltransferase UGTSL2N358F, which catalyzed the conversion of RebA into RebD, 78.8 g/L of RebM2 (with a yield of 84.56%) was produced from 70 g/L of RebA, avoiding the use of the naturally rare and poorly soluble RebD as the starting material. This work will provide a promising biocatalyst for RebM2 biosynthesis on a large scale and create an opportunity to accelerate the exploration of the biological activity of RebM2 and its potential as a candidate for superior SG sweeteners.

Open-jet testing: Investigating turbulence and geometric scale effects on surface pressures in the atmospheric boundary layer

Bluff body aerodynamics is essential for the design and safety of structures exposed to wind forces. Traditional atmospheric boundary layer wind testing often fails to replicate the complex turbulence characteristics of real-world flows, necessitating innovative testing methodologies. We developed an open-jet testing approach and conducted experiments on scaled models (1:7.6 and 1:10) at Reynolds numbers ranging from 0.5 × 106 to 1 × 106, significantly higher than those typically achieved in conventional testing. This methodology produced integral length scales approximately ten times larger than those observed in traditional methods, resulting in 25%–300% higher peak pressures than those from small-scale tests, closely aligning with full-scale field data. Our findings emphasize the necessity of testing under complete atmospheric boundary layer turbulence to ensure accurate wind pressure predictions. Insights into the effects of advanced flow on separation, reattachment, and pressure distribution inform new experimental protocols and have significant implications for the design and safety of structures in wind-prone regions. By establishing a robust benchmark for future experimental and computational simulations in wind engineering, this approach promotes the development of safer, more resilient, and economically viable building designs capable of withstanding extreme wind events exacerbated by climate change, contributing to sustainable infrastructure advancement.

DESIGN AND STATIC ANALYSIS OF PRISMATIC PRESSURE VESSELS ACCORDING TO TS 13445-3 STANDARD

The focus of the presented work is on the design and analysis of prismatic pressure vessels. Engineering calculations, design parameters and performance criteria of pressure vessels are available in the literature in detail, but there are deficiencies in the evaluation of the manufacturing processes of prismatic pressure vessels and the mathematical formulae required by these processes in the light of standards. In this context, it was investigated how a special prismatic pressure vessel, a square profile hyperbaric oxygen chamber, could be optimised in terms of structural strength, stress distribution and safety requirements. The material selection and design of such a chamber has been evaluated using DBA and DBF methods. The performance of the prismatic hyperbaric oxygen chamber in current applications is explained, supported by various engineering analyses and simulations. It was observed that the cabin designed in accordance with TS 13445-3 standards is 2 times safe under operating conditions and the amount of displacement is commercially acceptable. It is shown with SolidWorks analysis.

Integrated modelling and simulation method of hybrid systems based on X language

AbstractModel‐based systems engineering is now leading the way in supporting the design of complex products or systems. The integration of modelling and simulation of continuous‐discrete hybrid systems is the key of model‐based systems engineering. But the existing languages, formalisms and tools cannot support the unified modelling and simulation of hybrid systems and therefore reduces the efficiency of complex system development. To address this issue, this paper develops a design method of complex hybrid systems, which integrates modelling and simulation of the continuous‐discrete hybrid behaviour. Specifically, the authors provided a modelling method of hybrid systems based on the X language, a simulation method based on XDEVS, and a compilation algorithm to transform the hybrid model constructed with X language into XDEVS simulation files. In this way, the X language hybrid model can be automatically translated into XDEVS simulation files by a compiler. The simulation files can then be simulated by the XDEVS simulation engine. The obtained simulation results will be used to verify whether the design scheme meets the design requirements of the hybrid system. Finally, the correctness and feasibility of the proposed method are verified using a car‐driving model.

Exploring Eco-Friendly Paths: A Comparative Study of Emissions in Medium Speed Diesel Engines Utilizing Alternative Fuels through Simulation Analysis

In the ship industry, emissions from marine activities have been shown to influence air quality and climate, with pollutants such as sulphur dioxide (SO2), nitrogen oxides (NOₓ), and Carbon Dioxide (CO2). the International Maritime Organization (IMO) has implemented MARPOL Annex VI to reduce emissions from maritime activities, one of which is using alternative fuels. With the need of sustainable energy source of reducing emissions, the evaluation of alternative fuels becomes crucial. This study presents a comparative analysis of performance and environmental emissions from medium speed diesel engines utilizing different fuels, namely Biodiesel (B10-100), Heavy Fuel Oil (HFO), and Ultra Low Sulphur Fuel Oil (ULSFO) under various engine speed. the research was carried out using the Diesel-RK application with Internal Combustion Engine simulation that integrates thermodynamics and emission prediction algorithms to accurately represent the combustion process and subsequent pollutant formation. Parameters such as engine load, injection timing, and fuel properties are systematically varied to assess their impact on emissions of nitrogen oxides (NOₓ), sulfur dioxides (SO2), and carbon dioxide (CO2). Results indicate distinct performance and emission profiles for each fuel type in various engine speed. All Biodiesel and ULSFO demonstrates increasing NOₓ emissions compared to HFO with an average of 51.4%. However, they exhibit lower CO2 and SO2 compared to HFO with average of 3% for CO2 and 98.8% for SO2, this is due to higher oxygen content that can promote more efficient combustion, and both Biodiesel and ULSFO contains lower sulphur content.