Browse Topic: Mathematical models

Items (7,420)
In order to solve the ship emergencies that may occur in the process of tunnel navigation, the tunnel pontoon-type bank wall evacuation channel proposed in a large navigation building is taken as the research object. Based on Pathfinder evacuation software, a numerical model of pedestrian evacuation for 500 passenger ships in emergency situations such as fire in the navigation tunnel is established, and the evacuation simulation analysis and evacuation ability evaluation are completed. The analysis shows that the emergency evacuation time of personnel is at least about 21 minutes, and the bottleneck of emergency evacuation equipment for personnel in the navigation tunnel is at the entrance of the pontoon escape. The results provide guidance and suggestions for the design optimization of the evacuation channel of the tunnel bank wall in the later period.
Tao, RanLi, RanTang, WeibiHu, ZhifangQin, Pan
This study addresses the insufficient tractive trafficability of four-track unmanned amphibious tracked vehicles (UATV) in beach terrain by proposing an optimization strategy based on coordinated suspension height and hitch point adjustment. A mathematical model of vehicle drawbar pull was established to systematically analyze the influence mechanisms of vertical load distribution, suspension adjustment, and hitch point elevation on tractive trafficability. DEM-MBD coupling simulations revealed differentiated traction laws under sandy loam and clay conditions, particularly regarding track overlap effects. Results demonstrate that in sandy loam, rear-axle traversal over front-axle tracks reduces drawbar pull due to soil loosening, whereas track overlap enhances drawbar pull in clay through soil compaction. Nine suspension-hitch configurations were tested, validating optimization strategies: increased front-axle loading (Configuration a) in sandy loam and reduced front-axle loading
Chen, YaoyaoGao, XueWang, WenhaoXu, Xiaojun
According to the working characteristics of the tire changer, the movement characteristics of its rim clamping mechanism are analyzed, and the complex movement structure is abstracted and simplified into four identical six-bar mechanism subunits. One of the subunits is taken as the research object, and the mathematical model of kinematic analysis is established. Using MATLAB software to simulate and analyze the motion law of each component, the mechanical characteristics of the component are analyzed. The optimization of the design parameters of the “six-bar mechanism subunit” is realized, the rim clamping mechanism becomes more stable, and the clamping force follows the diameter of the rim more closely.
Zhao, FengqinZhou, LiyaoWang, MantongHuo, Fengwei
Unmanned Aerial Vehicles (UAVs) are now indispensable in low altitude urban logistics for their efficiency and versatility. In order to boost their practical performance in such a mission, in this paper, we study three typical UAV dispatching problems: (1) single UAV routing with battery constraints, (2) multi UAV task allocation and routing balance and (3) multi UAV minimization of UAVs with hard time window constrains. The mathematical models of each case are constructed, and the optimization algorithm such as greedy algorithm, cluster algorithm, genetic algorithm and simulated annealing algorithm are designed for each case. The simulation shows that greedy algorithm has better optimization in resource utilization and the convergence of the simulated annealing algorithm is better under the complex constraints. This results provide an algorithmic insight for the improved UAV scheduling problem in MUCLL environment.
Wang, JiamingGuo, JingDu, NingWei, Mengju
This study focuses on a hydrogen ejector for a proton exchange membrane fuel cell (PEMFC) with a maximum power of 150 kW. Experimental tests were conducted to obtain the operating parameters of the stack under 100 kW and 150 kW conditions, which were used as simulation boundary conditions. A three-dimensional numerical model of the ejector was established and validated. Based on this model, the effects of key structural parameters—including nozzle throat radius (Rnt ), nozzle position (NXP), mixing chamber radius (Rm ), diffuser outlet radius (Rde ), secondary flow inlet radius (Rs ), suction chamber radius (Rf ), and constant-pressure mixing chamber length (Lpm )—on ejector performance were systematically analyzed. The results indicate that Rnt and Rf are negatively correlated with ejector performance, while Rs and Lpm are positively correlated. In contrast, NXP, Rm , and Rde exhibit an optimal range, leading to a single-peak characteristic in ejector performance. This research
Liu, GuoqingTai, ShupengXi, FuqiangLi, ZongjiJi, ShaoboWang, XiuyuWei, Hui
During idling tests of a newly developed sport utility vehicle (SUV) under tropical high-temperature conditions, the condenser surface temperature exceeded the allowable range, degrading the air-conditioning system’s cooling performance. In this study, a three-dimensional computational fluid dynamics (CFD) model of the engine compartment flow field was established using STAR-CCM+. The results reveal that under idling conditions, the kinetic energy of hot air passing through the cooling module was insufficient to overcome the pressure difference between the front and rear sections, thus inducing hot air recirculation (HAR) and increasing the overall compartment temperature. To address the unfavorable flow field characteristics, four structural improvements were proposed and simulated for both flow and temperature fields. Through comparative analysis, the optimal scheme was determined: installing a flow guide baffle above the engine. Simulation results show that the airflow velocity
Shi, HuojieRao, R.H.Chen, J.Zheng, Z.L.
Mitigation of harmful emissions from oil-based engines is essential to avoid environmental pollution and comply with various NOx regulations across the globe. This can be partially achieved by injecting urea to produce ammonia (NH3), which reacts with NOx in a catalyst to produce harmless nitrogen (N2) and water vapor (H2O). However, urea deposition in a selective catalytic reduction (SCR) system poses a significant threat to the NOx removal process by not only reducing the urea conversion rate but also blocking the incoming flow and causing an additional pressure drop. Numerical modeling of this urea deposit formation involves multiphase flow physics coupled with accurate heat transfer calculations. Additionally, since urea decomposes into various by-products like biuret, cyanuric acid (CYA), and ammelide, detailed chemical kinetics modeling is equally important. Accurate and fast computational fluid dynamics (CFD) simulations can help accelerate SCR system design cycles, leading to a
Morab, Sumant R.Khalate, SurajAnsari, ShoaibYang, Pengze
This work investigates the integration of a Sorption Thermal Energy Storage (TES) into the Heating, Ventilation and Air Conditioning (HVAC) system of electric vehicles. The proposed device reduces the energy demand for cabin heating under winter conditions, leading to a driving range increase. The TES dehumidifies the cabin air through a desiccant bed (zeolite 4A), preventing window fogging, enabling higher air recirculation rates, and consequently reducing the required heating power. An experimentally validated numerical model was used to analyze the adsorption and regeneration processes and to identify suitable operating conditions. Regeneration was found to be effective at moderate temperatures (from 120°C), with a counter-current airflow configuration providing faster and more efficient desorption compared to parallel-flow one. A simplified model integrating TES, HVAC unit and cabin was developed and used to compare different configurations. Heating energy consumption with and
Verlingieri, RebeccaCalabrese, LuigiFreni, AngeloMarocco, LucaScudeler, GabrieleDe Antonellis, Stefano
The rising concerns on climate change is accelerating the transition from fossil fuel-based technologies to sustainable energy systems. In this framework, Proton Exchange Membrane Fuel Cells (PEMFCs) are gaining an increasing interest due to their high efficiency and wide range of applications. Nevertheless, these systems experience significant performance losses under high loads, associated with significant heat generation, making thermal management a fundamental design aspect. In this study, a 200-kW low temperature PEMFC was investigated through the development of a 0D – 1D model of a simplified cooling circuit implemented in GT – SUITE environment. The model was used to evaluate the influence of design parameters on the effective efficiency of the system to dissipate the excessive heat. Additionally, a detailed stack-only model, comprehensive of the Membrane Electrode Assembly (MEA) subcomponents, was developed to verify the temperature differences between coolant fluid and
Cecere, GiovanniAntetomaso, ChristianIrimescu, AdrianMerola, Simona
Opposed-piston free-piston engine generators (OFPEGs) are emerging as a promising technology for next-generation hybrid and electrified transportation systems due to their high efficiency, reduced mechanical complexity, and improved noise, vibration, and harshness (NVH) characteristics. However, due to eliminating the conventional crankshaft mechanism and directly coupling a free-piston engine with linear generators, performance of OFPEG systems is governed by a strong coupling between piston dynamics, in-cylinder combustion processes, and electrical loading conditions. This coupling presents substantial challenges for system design, control, and optimization, limiting the further development and application of OFPEGs. Existing researches lack a comprehensive numerical model that integrates detailed in-cylinder thermodynamic process with control system of linear generator, and quantitative analysis of the effect of piston motion trajectory on system performance remains insufficiently
Wang, JiayuMorandi, NicolaLucchini, TommasoFENG, HUIHUAJia, BoruRen, Peirong
Initial weight estimation from Top Level Aircraft Requirements (TLAR) is a critical first step in aircraft design, yet existing empirical methods are inadequate for novel configurations such as those using Liquid Hydrogen (LH2) or Sustainable Aviation Fuels (SAF). This paper presents a hybrid methodology for top-level weight estimation of such unconventional aircraft. The approach is based on modifying a conventional baseline aircraft, integrating a new statistical model with component-specific weight estimations. A multivariate regression model to estimate the empty weight fraction (We/W0) was developed from a dataset of 44 conventional aircraft, yielding an R-squared value of 0.833. This statistical model was integrated with physics-based models for novel components, including cryogenic fuel tanks and fuel systems. The methodology accounts for iterative changes to fuselage structure and parasitic drag. Four configurations were analyzed: fuel types being Jet A1, SAF, LH2 with aft
Goyal, Tushar
This study presents a data-driven approach for strengthening aviation safety by integrating human factors assessment with modern predictive modeling techniques. The work focuses on understanding how human performance, operational conditions, and system-level interactions collectively influence safety risk, and how these interactions can be quantified to support improved design and decision-making. Unlike previous studies that address human factors or predictive modeling in isolation, this research offers a unified framework that links causal human factors indicators with statistical modeling, feature extraction, and machine learning based risk estimation. The novelty of this work lies in the structured pipeline that transforms raw categorical and narrative human factors information into measurable predictors that can be analyzed using structural modeling and machine learning. The methodology includes data preparation, dimensionality reduction, latent pattern discovery, dependence
Valiyaparambil, Praveen
In the field of Aerospace, which has a long Life-Cycle process [20-30Years], Component Obsolescence has become a major problem as it prevents Maintenance & sustenance of a product with committed life-cycle period. Obsolescence Management plays a vital role by deriving strategic plans on proactive obsolescence where the system needs to be supported for several decades. This abstract analyzes the obsolescence challenges in the Aviation industry especially in Avionics System impacted by component obsolescence and present the possible proactive obsolescence management in terms of Engineering, Technology, and business/cost elements. The Obsolescence problem cannot be avoided but the impact of obsolescence and mitigate the risk can be minimized by planning and managing response. The obsolescence risk assessment for the Bill Of Materials (BOM) is a paramount activity to manage obsolescence proactively and cost-effectively. Digital Transformation of analyzing the component obsolescence status
Dharmananyala, RohithMunirathnam, KrishnaMarokeyfrancis, JoisyjoseSadashivaiah, NageshKondamari, Harshitha
Air Traffic Management (ATM) must be familiar with the exact Aircraft Take-off Weights (ATOWs) of airplanes to make the most use of runways, maintain safety margins high, and keep utilization and resources in balance. This paper aims to present a dependable ATOW forecasting methodology that can assist the air transport industry in enhancing operational decision-making. This research used datasets acquired from the EUROCONTROL Performance Review Commission (PRC) 2024 Aircraft Take-Off Weight Estimation dataset featuring 527,000 flights over Europe containing aircraft details, air trips and flight conditions. Technique comprises structured data input, inspection of missing data, timestamp aggregation to identify demand cycles over time, and domain-specific feature engineering using distance_per_minute, block_minutes, taxiout_ratio, and a strong wake turbulence metric The two supervised learning models used were Linear Regression (LR) for understanding and XGBoost for performance
Senthilkumar, N.S, GopalakrishnanGopinath, S
The analysis of wear particles within machinery lubricants constitutes a critical methodology for assessing equipment health and enabling the early identification of potential failures. However, conventional inductive abrasive particle sensors typically exhibit lower detection sensitivity compared to other sensing technologies, limiting their practical application in precision condition monitoring. To address this limitation, this paper introduces an inductive abrasive particle sensor with enhanced sensitivity and throughput, employing rectangular coils, together with a custom-designed signal conditioning circuit. The sensor features two symmetrically arranged rectangular excitation coils and two symmetrically arranged rectangular sensing coils, with their respective axes mutually perpendicular. This unique spatial configuration not only ensures strong magnetic field intensity within the detection region but also significantly enhances magnetic field utilization efficiency. The sensing
Jiang, ZiyangQian, MinHuang, HonglianLu, YanluZhang, JunjianPan, Chengliang
Soft robot systems demonstrate exceptional load-bearing capacity and spatial compliance during operation, with transformative potential in disaster response scenarios requiring adaptive morphology and hazardous material manipulation. By integrating the complementary advantages of soft robotics and particle jamming mechanisms, this study proposes a real-time variable-stiffness soft actuator, while systematically investigating its mathematical modeling framework and stiffness modulation principles. A deformation model for the variable stiffness soft actuator is established, followed by static analysis of the variable-stiffness members using particle jamming theory, with theoretical investigation of their stress distributions. Subsequently, a variable-stiffness driver was fabricated via additive manufacturing (3D printing), resulting in a flexible mechanical digit capable of stiffness tuning, A soft mechanical hand grasping test platform was built, and grasping experiments of objects of
Wang, JianYuan, HaiyangDeng, HaishunChen, Jiaxian
While large language models (LLMs) offer a convenient natural language interface for logistics optimization problems, it remains challenging to directly generate reliable mathematical models and executable code from unstructured text requirements. LLMs tend to produce invalid constraints or syntactically incorrect code. In addition, traditional logistics optimization methods lack the flexibility to adjust warehouse rules or operational goals without manual expert intervention. To address these issues, we propose LOOP (a Language-Model Orchestrated Optimization Pipeline), which automatically translates natural-language requirements into optimization algorithm code while retaining the rigor of classical models and solvers. LOOP leverages task-specific agents to construct accurate mathematical models and adopts a difference-driven code generation approach. First, it synchronizes model changes into executable code via semantic mapping and ensemble difference analysis. Second, it
Ding, RuiqingLi, QianyingLi, Xiaojian
If wear particles generated during the operation of automobile engines are not monitored in time, they will contaminate the lubricating oil, leading to system failures or even accidents. Therefore, real-time wear particle monitoring is crucial for the stable operation of engines. Among mainstream wear particle monitoring sensors, the three-coil inductive sensor demonstrates significant application potential due to its ability to distinguish wear particle materials and strong resistance to environmental interference. However, its insufficient sensitivity to small-diameter wear particles limits further performance improvement. This paper takes the three-coil inductive wear particle monitoring sensor as the research object. First, a mathematical model of the sensor’s operation is established based on the law of electromagnetic induction, clarifying the relationship between structural parameters (such as channel radius, turns, coil spacing, and length) and the peak induced voltage
Yin, HaoZhao, LijunShen, Yitao
The bird strike performance of rotorcraft components must be demonstrated to the airworthiness authority in accordance with the certification requirements of CS 29.631. This necessitates continuous efforts to design and validate birdstrike-resistant structures through a combination of experiments and simulations. In this study, an integrated experimental and numerical investigation is conducted to evaluate the structural response and failure characteristics of the main rotor pitch link subjected to bird impact. In the experimental program, high-speed imaging and strain measurements were used to capture the transient deformation and impact force history. In parallel, a highly nonlinear finite element model was developed using the LS-DYNA solver. The numerical model was validated against experimental results. Results demonstrate that localized plastic deformation and stress concentrations occur near the impact region, consistent with damage patterns observed in real-world incidents. This
Acar, Nagehan NurKambur, Çağdaş
The design, testing, and analysis of a Guided Autorotative Delivery System (GADS) for suppression of incipient wildfires is described. The GADS consists of an unpowered 1 m diameter rotor, a control unit, and a payload of 2.2 kg of fire suppressant powder. On release from a fixed-wing UAV, the rotor passively deploys and enters autorotation, decelerating the payload and allowing precise delivery of the suppressant using cyclic pitch control. A numerical model of the system was developed to calculate the trajectory of the GADS during rotor deployment and descent, in the presence of ambient wind and cyclic pitch inputs. A reduced-scale model of the rotor was tested in a wind tunnel, and an uncontrolled full-scale, 1.5 kg prototype of the GADS was fabricated and tested by dropping from a hovering quadcopter as well as a fixed-wing UAV. The full-scale drop experiments validated the deployment and autorotation stability of the system, and demonstrated that the GADS maintains descent
Chadha, JiaJain, RheaSakamuri, SivaThomas, ThomasSirohi, Jayant
While an enlarged lead time from risk notifications to collisions is widely acknowledged to facilitate safe driving, it remains challenging to effectively notify drivers of invisible risks and non-apparent risks coming from uncertain behaviors on the part of road users. The current study examined whether verbal notifications are able to assist early awareness of predictive risks. We also attempted to identify human and environmental factors that could possibly improve the effectiveness of predictive risk information. Twenty-eight licensed drivers participated in a public road test conducted in two different urban areas on 3 days. They drove predefined courses on which potential risk locations were identified prior to the test, using a sport utility vehicle equipped with an automatic verbal notification system triggered based on the distance to the potential risk locations. After passing through the locations each time, the participants were instructed to verbally evaluate the shift in
Maruyama, MasakiKoyama, KeiichiroEzaki, ToruSakamoto, JunichiSawada, YutaMatsuoka, Takahiro
Accurately modeling and controlling vehicle exhaust emissions, particularly during highly transient events such as rapid acceleration, is crucial for meeting stringent environmental regulations and optimizing modern powertrain systems. While conventional data-driven modeling methods, such as Multilayer Perceptrons (MLPs) and Long Short-Term Memory (LSTM) networks, have improved upon earlier phenomenological or physics-based models, they often struggle to capture the complex nonlinear dynamics of emission formation. These monolithic architectures attempt to learn from all available data, which increases their sensitivity to dataset variability. They often require increasingly deep and complex architectures to improve performance, thereby limiting their practical utility. This paper introduces a novel approach that overcomes these limitations by modeling emission dynamics in a structured latent space. Using a rich dataset combining real-world driving data from a Portable Emission
Sundaram, GaneshGehra, TobiasUlmen, JonasHeubaum, MirjanGörges, DanielGünthner, Michael
Moving ground wind tunnels offer a more accurate test environment for ground vehicle drag coefficient measurement due to their highly realistic representation of the boundary layer phenomenon. However, historically most vehicles have been tested on static ground wind tunnels. As a result, the measured drag coefficient of these vehicles may not be sufficiently realistic for certification purposes. Therefore, it is valuable to build statistical models to estimate moving ground wind tunnel drag coefficient by using information from a static ground wind tunnel and other relevant vehicle characteristics such as presence of aerodynamic devices (spoilers, air dams, etc.). However, to build accurate statistical models, appropriate predictive features must be identified as a first step. In this paper, an aerodynamic feature selection study has been conducted to identify vehicle characteristics that contribute to drag coefficient estimation discrepancies between a static- and a moving ground
Singh, YuvrajJayakumar, AdithyaRizzoni, Giorgio
Longitudinal lumbar acceleration is often overlooked as a key variable when biomechanically assessing lumbar response in rear-end collisions. The objective of this study is twofold: (1) to conduct a comprehensive literature review of peak longitudinal lumbar acceleration to statistically evaluate differences between three surrogate occupant types: human volunteers, post-mortem human subjects (PMHS), and anthropomorphic test devices (ATDs) and (2) to construct a mathematical predictive model of longitudinal lumbar acceleration using peak longitudinal vehicle or sled change in velocity (delta-V) and vehicle acceleration in rear-end impacts. Peak longitudinal lumbar acceleration was obtained from peer-reviewed literature and the Insurance Institute for Highway Safety database. Tests included belted human volunteers, PMHS, and ATD occupants seated upright in unmodified, conventional driver seats. Compared to human volunteers instrumented at L5-S1, BioRID ATDs instrumented at L1 displayed
Zambare, KeyaOgbu Felix, JordanArana Barcala, EmilyWestrom, ClydeCaraan, JohnAdanty, KevinShimada, Sean
A simulation-based aerodynamics model of the Honda Automotive Laboratories of Ohio (HALO) Wind Tunnel, a three-quarter open-jet (ground plane) configuration opened in 2022 for full-scale automotive testing, was initiated to support data fusion for more accurate surrogate models in vehicle engineering programs. The objective was to demonstrate that a matched set of boundary values between the physical wind tunnel and the three-dimensional numerical model yield correct responses for several key flow field quantities, starting with the baseline empty tunnel case: (1) streamwise static pressure distribution, (2) evolution of the free shear layers downstream of the nozzle exit plane, and (3) ground-plane boundary layer development. Pressure-based measurement probes were deployed in these regions using a four-axis overhead traverse to acquire validation data in the large facility, including instrument verification between a 14-hole probe and Pitot-static rake. Detached eddy simulation (DES
Patel, SajanDisotell, KevinEagles, Naethan
Battery thermal runaway is a major safety concern in electric vehicles because of the extreme heat and hazardous gases released during cell failure. These venting events can quickly raise the temperature of the battery enclosure and cabin floor, threatening occupant safety. To address this challenge, this study employs the Design for Six Sigma (DFSS) methodology to design and optimize a thermal protection system that delays and limits heat transfer to the cabin. A physics-based transient heat-transfer model was combined with DFSS principles to systematically evaluate insulation materials, shield layouts, surface emissivity, and layer geometry. An L-18 orthogonal array was used to identify key parameters and quantify their influence on thermal robustness. The optimized architecture reduced cabin-floor temperature rise under severe runaway conditions (600–900 °C vent gas), meeting occupant-egress safety requirements. Findings confirm DFSS as an effective framework for developing high
El-Sharkawy, AlaaAsar, MonaTaha, NahlaSheta, Mai
Trust calibration is vital for safe human–automation interaction but remains largely qualitative. This study develops multiple quantitative frameworks modeling trust as a function of automation reliability. Four progressive models of binary, linear, triangular, and logistic formalize the calibrated trust zone, defining where human reliance aligns with system performance. The framework corrects major misconceptions: that trust is purely qualitative, that low trust–low reliability states are acceptable, and that overtrust and distrust pose equal risk. It establishes a minimum reliability threshold for meaningful trust and identifies distrust as the safer default in high-risk contexts. A case study on an empirical observation of 32 AI applications plotted in the trust–reliability space confirms the analysis, revealing a consistent distrust tendency where reliability exceeds user confidence and other observations. By quantifying trust through reliability, the study reframes it as a
Wen, HeMounir, Adil
Viscoelastic behavior of polymeric materials serves as a critical indicator of their internal structure and chemical composition, offering valuable insights into energy absorption and dissipation mechanisms. This study focuses on the dynamic characterization of polymer foams through both experimental and numerical approaches, aiming to accurately capture their time and frequency dependent mechanical response. Experimental investigations include uniaxial tension and uniaxial compression, which characterize hyperelastic or instantaneous behavior of the material. Stress relaxation tests and Dynamic Mechanical Analysis (DMA) characterize the dependence on time and frequency. A combination of these tests is effectively utilized to create viscoelastic material models that can describe the material response as a function of time and frequency containing a viscous and an elastic part. This paper presents dynamic characterization of polymer foams in finite element simulations. Theoretical
M, Gokula KrishnanLin, ChunfuSavic, Vesna
Hydraulic braking torque and motor braking torque are the main sources of braking torque of new energy vehicles. Hydraulic braking converts vehicle kinetic energy into heat dissipation, and motor braking converts vehicle kinetic energy into electric energy to achieve energy recovery. In the process of vehicle braking, when the wheels tend to lock, it is easy to cause vehicle instability, which seriously threatens the safety of driving. Therefore, how to coordinate the braking torque of the two braking systems to ensure the vehicle braking safety and energy recovery efficiency is still an urgent problem to be solved. In this paper, the electric vehicle equipped with electro-hydraulic compound braking system is taken as the research object, and the electro-hydraulic compound braking coordinated control strategy considering the general braking state and emergency braking state is proposed. Firstly, a 3-DOF vehicle longitudinal dynamic model is established according to the vehicle dynamic
Zhao, BinggenZhao, BingquanZhang, XiaoyangWang, ZhenfengZhao, GaomingHe, ChengkunZhang, JunzhiMa, Changye
Ammonia has emerged as a viable hydrogen energy carrier owing to its superior hydrogen density and mature industrial utilization. However, ammonia faces critical challenges including inadequate ignition characteristics and sluggish combustion kinetics, necessitating supplementary high-reactivity fuels for optimizing combustion. Onboard ammonia decomposition technology resolves this problem through on-demand hydrogen real-time production. Among existing ammonia decomposition methods, gliding arc plasma (GAP) demonstrates exceptional promise for onboard hydrogen production given its high processing flow rate,decent hydrogen conversion rate, and transient response capability. Prevailing research predominantly relies on experimental approaches, with insufficient understanding of the effects of specific electrical field parameters and inlet pressure on system performance. This study established a quasi-one-dimensional numerical model for GAP-assisted ammonia decomposition. A comprehensive
Dong, GuangyuLi, XianZhou, YanxiongXu, JieLi, Liguang
As motorsports evolve with technological advancements, aerodynamics plays a crucial role in race car performance. This review examines the impact of aerodynamics on car design and its evolution, presenting a statistical analysis of existing sports cars. We highlight key performance factors like engine power, top speed, drag, and weight. The key contribution of this review is the critical synthesis of the safety-performance trade-off, especially linking aerodynamic optimizations to the stability and safety of sports cars. Furthermore, we explore mathematical modeling of vehicle aerodynamics to enhance the understanding of performance aspects such as top speed, acceleration, cornering, and braking. This article also provides a review of recent active and passive aerodynamic devices to assist researchers in selecting designs, with an emphasis on the importance of ground effect. We also present recent numerical methods, particularly 3D simulations. The statistical data can help researchers
Eftekhari, HesamAl-Obaidi, Abdulkareem Sh. MahdiEftekhari, Shahrooz
Free-piston engine generator (FPEG), as a novel energy conversion device, has the advantages of good fuel adaptability and high energy utilization. Combustion variation between cycles poses a significant challenge to the running control of an FPEG. A hierarchical control strategy, including motion, combustion, and generation power controllers, is designed in this paper to achieve the stable and efficient running of a hydrogen-fueled opposed-cylinder FPEG prototype. Piston motion is controlled by adjusting the generation current, which is adjusted through iterative learning using piston displacement feedback and adaptive control using piston velocity feedback. Generating power is regulated by controlling the throttle opening angle, which is adjusted through iterative learning. A multidisciplinary joint mathematical model is developed to simulate the dynamic characteristics and verify the control strategy. The simulation results reveals that the dead center position accuracy can be
Wang, JieshengLiu, LiangXu, Zhaoping
This study investigates the feasibility of a novel internal combustion engine (ICE) architecture, termed the membrane engine, in which the conventional piston is replaced by a flexible elastic membrane. Although the concept appears in several patent documents proposing reduced friction, improved sealing, and lower heat losses, no empirical data has been published to support these claims. To the authors’ knowledge, this work presents the first membrane engine built and experimentally tested. The primary aim is to verify whether such an engine can operate as a functional ICE, regardless of its current efficiency or performance level. To support concept validation, a simplified mathematical model was developed to describe the membrane’s deformation and its effect on combustion chamber volume. Unlike conventional piston engines, the membrane introduces a pressure-dependent geometry, enabling a variable compression ratio. The model is not intended to predict performance but to assist in
Allmägi, RolandIlves, Risto
SAE J2998 defines the recommended information content to be included for documenting dynamical models used for simulation of ground vehicle systems. It describes the information that should be compiled to describe a model for the following user applications or use cases: (1) exchange, promotion, and selection; (2) creation requests; (3) development process management; (4) compatibility evaluation; (5) testing-in-the-loop simulations with hardware and/or software; (6) simulation applications; and (7) development and maintenance. For each use case, a model description documentation (MDD) template is provided in the appendices to facilitate model documentation. In addition, an example of a completed model documentation template is provided in the appendices.
Dynamical Modeling and Simulation Committee
Hydrogen Fuel Cell Electric Vehicles (FCEVs) represent a significant trajectory in vehicular decarbonization, harnessing the inherently high energy density of diatomic hydrogen within electrochemical conversion systems. When sourced via renewable pathways, such hydrogen facilitates propulsion architectures characterized by zero tailpipe emissions, enhanced energy efficiency, and extended operational range profiles. Realizing peak systemic efficacy necessitates the synergistic orchestration of high-fidelity fuel cell stack design, resilient compressed gas storage modalities, and nuanced energy governance protocols. To reduce transient stressors and guarantee long-term electrochemical stability, employing multi-scale modeling and predictive simulation, combined with constraint-aware architectural synthesis, is crucial in handling stochastic driving conditions spectra. This study develops a high-fidelity mathematical plant model of a hydrogen Proton Exchange Membrane (PEM) fuel cell
Mulik, Rakesh VilasraoE, PorpathamSenthilkumar, Arumugam
The customer perception of ride comfort with vehicle performance is the most important aspect in a vehicle design. The ride comfort and vehicle performance are influenced by driveline components i.e. propeller shaft phase angle, inclination angle and critical frequency of the driveline system. The optimization of the driveline system is essential to ensure the efficient and smooth power transfer. Propeller shaft is one of the critical components in the driveline to influence the vehicle performance. Propeller shaft characteristics influenced by several factors like vehicle max torque, propeller shaft joint type, materials properties, UJ phase and inclination angle and shaft unbalance value. The optimization of the above parameter within the tolerance limit enables to meet the required performance standard. Various methodologies are available to optimize these parameters to enhance the vehicle performance and comfort leads to customer satisfactions. This study focuses on the analytical
Kumar, SarveshSanjay, LS, ManickarajaKanagaraj, Pothiraj
In driving, steering serves as the input mechanism to control the vehicle's direction. The driver adjusts the steering input to guide the vehicle along the desired path. During manoeuvres such as parking or U-turns, the steering wheel is often turned fully from lock to lock and then released. It is expected that the steering wheel quickly returns to its original position. Steering returnability is defined as the ratio of the difference between the steering wheel position at lock to lock and the steering wheel angle after 3 seconds of release, to the steering wheel angle at the lock position, under steady-state cornering conditions at 10 km/h. Industry standards dictate that the steering system should achieve 75% returnability under these conditions within 3 seconds. Achieving proper steering returnability characteristics is a critical aspect of vehicle design. Vehicles equipped with Electric Power-Assisted Steering (EPS) systems can more easily meet returnability targets since the
Singh, Ram Krishnanahire, ManojJAIN, PRIYAVellandi, VikramanSUNDARAM, RAGHUPATHIPaua, Ketan
Model Based Design (MBD) uses mathematical modelling to create, test and refine systems in simulated environment, primarily applied in control system development. This paper discusses an approach to control gear shifting using shift logic on vehicle level for twin clutch transmission using prototype controller. Twin clutch transmission is a concept with two clutches, one at input end of the transmission called primary clutch and the other at output end of the transmission called secondary clutch. This concept is proposed to counter the challenges with conventional transmission which include increased gear shift time and effort in lower gears, potential rollback of vehicle in uphill condition and chance of missed shifts. The advantages of this concept include reduced gear shift effort and improved synchronizer life with potential for reducing the size of the synchro pack. This paper proposes a methodology to develop shift logic, integrate hardware with software, flashing and calibration
Patel, HiralThambala, PrashanthTongaonkar, YogeshMosthaf, JoergMalpure, Khushal
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