Vehicle Design Research Articles

Compilation of wheel-rail comprehensive irregularity spectrum for subway vehicle

The irregularity excitation experienced by subway vehicles is mainly the result of the interaction between the track and wheel. However, in the early system design and simulation analysis of subway vehicles, most only used the traditional standard track irregularity spectrum as the input excitation, ignoring or underestimating the contribution of the wheel irregularity. Based on our statistical analysis of 200,000 kilometers of tracking test data of subway vehicle wheel irregularities, we found that the short-wave irregularity caused by the wheels far exceeds the traditional standard track irregularity. The service condition of the vehicle is seriously affected, especially in the final stage of a wheel re-profile period. To address the above issues: Firstly, the sensitive wavelength range (16. 67∼2500 mm) of subway vehicles was derived based on the axle box acceleration spectrum of IEC61373: 2010, which was very close to the wavelength range (50∼2627 mm) of the wheel irregularity spectrum proposed later, demonstrating the importance of compiling a wheel irregularity spectrum; Secondly, based on the large number of tracking test data of wheel out-of-roundness, a calculation method of the wheel irregularity quantile spectrum under the Johnson non-normal transformation system was proposed; Thirdly, according to the different stages of the wheel re-profile period, the wheel irregularity spectrum is introduced to correct the short-wave segments of the traditional standard track irregularity spectrum to compile a wheel-rail comprehensive irregularity spectrum.

Optimal Motion Design for Autonomous Vehicles With Learning Aided Robust Control

Optimal Motion Design for Autonomous Vehicles With Learning Aided Robust Control

Pluralism and the Design of Autonomous Vehicles

This paper advocates for an ethical analysis of autonomous vehicle systems (AVSs) based on a moral epistemic pluralism. This paper contends that approaching the design of intricate social technologies, such as AVSs, is most effective when acknowledging a diverse range of values. Additionally, a comprehensive ethical framework for autonomous vehicles should be applied across two interconnected layers. The first layer centers on the individual level, where each autonomous vehicle becomes a unit of moral consideration. The second layer focuses on the system level, directing moral attention toward the intricate autonomous vehicle system as a whole. Distinguishing the approach from metaphysical pluralism, the paper responds to counterarguments from a moral relativist and value monist perspectives. It concludes by emphasizing the necessity of embracing epistemic pluralism to navigate the complex ethical landscape of AVSs, urging a holistic understanding that transcends individual events and integrates system-level considerations.

Study on the influence of high-temperature thermochemical nonequilibrium effects on the flow field characteristics around shaped wing

With advances in research on hypersonic vehicles, the precise simulation of the effects of thermochemical non-equilibrium has become increasingly important in their design. In light of this, this study explores the influence of high-temperature thermochemical non-equilibrium on the characteristics of the flow field around the hypersonic wings of an aircraft. We initially conducted a numerical simulation by using the model of flow through a cylinder to validate the accuracy and reliability of an 11-species gas model in representing high-enthalpy flow fields. Subsequently, a systematic analysis was conducted on the impact of thermochemical nonequilibrium effects on the temperature, pressure, and enthalpy distribution in the flow field around a symmetric diamond wing under different Mach numbers and angles of attack. The research results indicated that the deeper reason behind the differing thermochemical nonequilibrium effects in the flow field at various Mach numbers lies in the distinct distribution of enthalpy of the air components at different locations, which provided a new perspective for understanding flow field variations from the standpoint of enthalpy. It is disclosed that the thermochemical non-equilibrium significantly altered the characteristics of the flow field, particularly at high Mach numbers and angles of attack, with a significant impact on the aerodynamic parameters of both the windward and the leeward sides of the wing. Through explaining the mechanisms of thermochemical non-equilibrium under flow fields with different structures, this study provides a theoretical foundations for and a fresh perspective on the design of hypersonic vehicles.

Aerodynamic Analysis of Si Jayaraya: A CFD Approach to Energy-Efficient Vehicle Design

Aerodynamic Analysis of Si Jayaraya: A CFD Approach to Energy-Efficient Vehicle Design

Analytical Analysis of Buckling Of Layered Composite Columns

Abstract: Lightweight composite construction is of great interest in the design and manufacture of spacecraft and marine vehicles because of high specific stiffness and strength. In addition, sandwich construction offers enhanced corrosion resistance, noise suppression and reduction in life-cycle costs. There are several issues and questions related to the use of composite construction that require attention and answers. One of the important issues is the prediction of buckling loads, under either static or sudden load application. For the static case, closed form solutions are derived for a symmetric composite column under axial compression and for various boundary conditions. In this study, improved analytical models are developed to characterize interface behavior of layered composite column-type structures. The mechanics models of the bonded interface with and without adhesive layer are established, from which the interface fracture, delamination buckling, free vibration and stress analysis across the adhesive layer of corresponding interface are studied.

Molecular simulation on solubilization of fullerene C60 by C12E6 nonionic surfactants

ABSTRACT Coarse grained simulations were adopted to describe the encapsulation and dispersion of fullerene C 60 by hexaoxyethylene dodecyl ether (C 12 E 6 ) surfactants. The self-organised structures of C 12 E 6 molecules in water were captured and the characteristics of micelles composed of different number of C 12 E 6 molecules were analysed. We found that C 60 molecules alone or in clusters can spontaneously translate into the hydrophobic core of micelles. One monomeric C 60 can explore the hydrocarbon-chain region of the micelles with different sizes, and two different preferential locations of C 60 are observed. The small C 60 clusters can disaggregate after entering the micelle. Larger C 60 clusters can penetrate into the micelle as solid-like nanoparticles, although they are partially disaggregated. When investigating the self-assembly of C 12 E 6 surfactants and C 60 molecules, we found that it is very difficult to disperse C 60 in the micelle monomolecularly. At high molar ratio of C 12 E 6 /C 60 , colloidal nanoC 60 aggregates form with C 12 E 6 surfactants adsorbed on the surface. Our simulations provide an explanation for the different observations in fullerene solubilization in micellar solutions and give a guideline for further solubilization of pristine fullerene or small hydrophobic molecules with surfacant micelles, which is helpful for the design of new micelle-based delivery vehicles.

Axial Crushing and Energy Absorption Integrated Design of Modular Filled Double-Hat Beam Composite Structures.

In order to study the influence of modular filled and composite material forms on the axial crushing and energy absorption properties of structures, modular filled composite structures were constructed, and innovatively applied to the inner side of double-hat beam (DHB) structures in automobiles. The modular filled structures comprise hexagonal, quadrilateral, and triangular sections. By analyzing the collision performance of modular filled DHB structures, significant enhancements were observed in both the sectional characteristics and the specific Mean Crushing Force of modular filled DHBs compared to the conventional double-hat beam structure. These advancements notably improved the plastic deformation characteristics of the structures. Additionally, dynamic weightlessness experiments were conducted to validate the accuracy of the simulation model. Among the proposed schemes, namely QU-5, HE-5, and TR-5, notable improvements in crashworthiness were identified. Specifically, crashworthiness indicators increased by 32.54%, 78.9%, and 116.53%. Compared with other thin-walled structures, modular filled composite DHBs have advantages in axial crushing and energy absorption. By optimizing layout characteristics, the modular filled structures will achieve significant lightweight and energy absorption performance improvements. This work has clear reference value for automotive engineers and scholars to further explore the axial crash safety, platform modularization, and lightweight design of vehicles.

Optimizing vehicle Front-End structure for e-bike rider Safety: An advanced Multi-Objective approach using injury prediction models

A multi-objective optimization method based on an injury prediction model is proposed to address the increasingly prominent safety issues for e-bike riders in Chinese road traffic. This method aims to enhance the protective effect of vehicle front-end for e-bike riders by encompassing a broader range of test scenarios. Initially, large-scale rider injury response data were collected using automated Madymo simulations. A machine learning model was then trained to accurately predict the risk of rider injury under varied crash conditions. Subsequently, this model was integrated into a multi-objective optimization framework, combined with multi-criteria decision analysis, to effectively evaluate and rank various design alternatives on the Pareto frontier. This process entailed a comparative analysis of the design in a baseline scenario before and after optimization, focusing on both kinematic and injury responses of riders. Through detailed injury mechanism analysis, key design variables such as the height of the hood front and the width of the bumper were identified. This led to the proposal of specific optimization strategies for these structural parameters. The results from this study demonstrate that the proposed optimization method not only guides the design process accurately and efficiently but also balances the injury risks across different body parts. This approach significantly reduces the injury risk for riders in car-to-e-bike collisions and provides actionable insights for vehicle design enhancements.

An Elderly-Oriented Form Design of Low-Speed New Energy Vehicles Based on Rough Set Theory and Support Vector Regression

With the current trend of social aging, the travel needs of the elderly are increasingly prominent. As a means of urban transportation, low-speed new energy vehicles (NEVs) are widely used among the elderly. Many studies are devoted to exploring the function of cars and the travel modes that meet the needs of older people. However, in addition to product performance, the Kansei needs of users also play a key role in communication between enterprises and users. Therefore, the problem of how to improve car shapes in the initial stage of design to meet the Kansei needs of elderly users remains to be solved. In order to fill this gap, the design of low-speed NEVs are selected as the study objects so as to explore the relationship between the visual perception of elderly users and car design; thus, a design method for the form of elderly-oriented cars is proposed. Firstly, using the research framework of Kansei engineering, factor analysis is used to cluster elderly-oriented Kansei factors. Second, the cars’ appearances are deconstructed by morphological analysis, and the key design features affecting elderly-oriented satisfaction are identified by a rough set attribute reduction algorithm. Finally, support vector regression is used to establish a mapping model of elderly-oriented Kansei factors and the key design features to predict the elderly-oriented form design of optimal low-speed NEVs. The research results show that selecting “Hub6”, “Headlight9”, “Car side view2”, “Rearview mirror9”, and “Front door10” in the form deconstruction table for low-speed NEVs can elicit optimal emotions in elderly users. The research results enable enterprises to more effectively understand the emotional cognition of elderly users related to the form of low-speed NEVs and improve the purchase desire and satisfaction of elderly users, providing references and guidance for the elderly-oriented design and development of intelligent transportation tools.

Design of an active wing-folding biomimetic flapping-wing air vehicle

In nature, birds and bats dynamically alter their wing shapes to suit various flight environments and tasks. This paper focuses on the design and validation of a biomimetic flapping-wing aerial vehicle, named FlexiWing, which features a unique mechanism for active wing deformation. This mechanism allows the wings to adjust their shapes flexibly in response to flight demands, significantly enhancing attitude control and maneuverability.’ ‘This study began with an in-depth exploration of biomimetic principles, focusing particularly on how birds and bats achieve precise control during flight through active wing deformation. Subsequently, we present a detailed account of the design and fabrication process of the active folding biomimetic flapping-wing aerial vehicle, including the design of mechanical mechanisms and material selection. Utilizing lightweight nylon materials and hollow carbon fiber rods, we successfully constructed a mechanically foldable wing structure. To achieve precise control over the aircraft’s movement, an embedded control system was designed, comprising an onboard embedded flight controller and ground-based equipment. The onboard controller uses a high-performance ESP32-C3 processor and a JY901 inertial measurement unit to acquire real-time attitude information of the aircraft. The control system incorporates Wi-Fi communication technology, enabling operators to send commands via a remote control or personal computer to manage flight modes and attitudes. Ultimately, a series of flight experiments were conducted to validate the performance of FlexiWing. The results demonstrate that FlexiWing exhibits remarkable maneuverability and stability, capable of achieving high-precision attitude control through active wing folding, making it adaptable to complex environments and tasks.’

Scientific benchmarking: Engineering quality evaluation of electric vehicle concepts

We present a simulation tool that utilizes advanced modeling techniques to quantify the customer-relevant features of different battery electric vehicles (BEV) concepts. By incorporating comprehensive longitudinal and lateral dynamics analyses, the tool provides an in-depth understanding of passenger vehicle concepts in various driving conditions. Furthermore, the tool emphasizes evaluating comfort, presenting a holistic view concluding into the overall driving experience. Metrics considering the vehicle’s packaging are employed to assess the comfort aspects of the concepts. Implementing this simulation tool achieves a more systematic and reliable approach to evaluating BEV concepts. The application based on the parameters of 18 state-of-the-art BEV proved its compliance in the presented categories with the results of physical tests performed by reputable magazines with great experience and comprehensice test protocols. Its academic foundation ensures the utilization of state-of-the-art methodologies and the integration of the latest research findings in vehicle dynamics and comfort. This simulation tool offers automotive engineers, researchers, and industry stakeholders a valuable resource for objectively assessing and benchmarking the performance and comfort aspects of BEV concepts. With its ability to provide accurate evaluations and reasoning for weaknesses, this tool has the potential to significantly contribute to the advancement and optimization of future electric vehicle designs by assessing concepts in early development stages before physical prototypes are available, allowing for cost-efficient modifications.

Analysis on the evolution of cavitation and flow field of vehicles entering water vertically at high speed

A numerical method is developed to consider the effects of fluid force and structural deformation on the flow field. The accuracy of the method is verified by experiments. The cavity evolution process are studied, and the characteristics of the velocity and vortex in the calculated flow field region are analyzed. The motion process of the dynamic wall of the cavity around the vehicle is simulated, and the phenomena of vortex distribution in the wake of the vehicle, instability in the wake of the cavity, and multistage closure of the cavity wall are obtained. It is revealed that the closing of the cavity will cause the velocity of the flow field inside the cavity to be reduced, and the return jet generated by the closing of the cavity will hit the vehicle and cause its attitude to be deflected. The peak velocity of the cavity wall appears at the position of cavity closure and the position of head cavity generation. The vortex scale around the vehicle gradually increases from the head of the body towards the top of the water surface. The research in this paper provides reference for the design of water entry vehicle.

A comprehensive review on architectural design and development of flexible photovoltaic solar panel

This review article aims to investigate the potential of flexible solar panels to revolutionize building and vehicle roofing design. The study explores the technology, its advantages over conventional panels, and architectural design considerations for seamless integration into curved surfaces. Flexible solar panels represent an emerging technology with the potential to transform the aesthetics and functionality of buildings and vehicles. Unlike rigid panels, flexible solar cells can conform to curved surfaces, offering new possibilities for architectural design and energy generation. This review comprehensively explores the technology behind flexible solar panels, comparing their characteristics to conventional flat panels. It delves into architectural design considerations, examining various methods and tools employed for optimizing panel shape, arrangement, and integration within the built environment. The findings of this review highlight the significant advantages of flexible solar panels in terms of aesthetic appeal and design flexibility. The ability to seamlessly integrate these panels into curved surfaces opens up new possibilities for architectural innovation. Flexible solar panels have the potential to become an integral component of future building and vehicle design. By overcoming the limitations of traditional solar technology, these panels can contribute to sustainable energy generation while enhancing the visual appeal of structures. Further research and development are necessary to optimize the efficiency and durability of flexible solar panels for extensive adoption.

Advanced UAV Design Optimization Through Deep Learning-Based Surrogate Models

The conceptual design of unmanned aerial vehicles (UAVs) presents significant multidisciplinary challenges requiring the optimization of aerodynamic and structural performance, stealth, and propulsion efficiency. This work addresses these challenges by integrating deep neural networks with a multiobjective genetic algorithm to optimize UAV configurations. The proposed framework enables a comprehensive evaluation of design alternatives by estimating key performance metrics required for different operational requirements. The design process resulted in a significant improvement in computational time over traditional methods by more than three orders of magnitude. The findings illustrate the framework’s capability to optimize UAV designs for a variety of mission scenarios, including specialized tasks such as intelligence, surveillance, and reconnaissance (ISR), combat air patrol (CAP), and Suppression of Enemy Air Defenses (SEAD). This flexibility and adaptability was demonstrated through a case study, showcasing the method’s effectiveness in tailoring UAV configurations to meet specific operational requirements while balancing trade-offs between aerodynamic efficiency, stealth, and structural weight. Additionally, these results underscore the transformative impact of integrating AI into the early stages of the design process, facilitating rapid prototyping and innovation in aerospace engineering. Consequently, the current work demonstrates the potential of AI-driven optimization to revolutionize UAV design by providing a robust and effective tool for solving complex engineering problems.

Hydrodynamic Analysis and Drag-Reduction Design of an Unmanned Underwater Vehicle Based on Computational Fluid Dynamics

Hydrodynamic Analysis and Drag-Reduction Design of an Unmanned Underwater Vehicle Based on Computational Fluid Dynamics

Research on Interior Design of New Energy Vehicles under the Concept of Information Materialization

This research focuses on the interior designing of electric vehicles (EVs), considered as new energy vehicles (NEVs), within the information materialization framework. The idea of information materialization refers to the quantifiable demonstrations of given data within the vehicle interior space, enhancing user interactions and experiences. Considering the State of Charge (SoC) as the crucial designing parameter, the research investigates the several implications of SoC on NEV interior designing. SoC, a critical parameter that reflects the battery's charging level, profoundly influence the merging of SoC data into the vehicle's dashboard or infotainment systems, ensuring seamless accessibility and intuitive interpretations for the driver. Instant alerts and notifications are designed based on SoC levels to provide real-time feedback and guidance to end users, optimizing driving ranges and strategies for charging. Furthermore, the study emphasizes the significance of customization options in SoC displaying formats and accommodates varying users preferences and requirements of visibility. Analysis of empirical and feedback from users, the research confirms the effectiveness of SoC-driven designing intervention in enhancing user experiences, safety, and overall functionalities interiors of NEV. The findings underscore the pivotal role of SoC as a fundamental designing parameter in shaping the next generations of NEV interiors and highlight the need for complete consideration of energy management aspects in future vehicle design endeavors.

Age-dependent changes in phagocytic activity: in vivo response of mouse pulmonary antigen presenting cells to direct lung delivery of charged PEGDA nanoparticles

BackgroundCurrent needle-based vaccination for respiratory viruses is ineffective at producing sufficient, long-lasting local immunity in the elderly. Direct pulmonary delivery to the resident local pulmonary immune cells can create long-term mucosal responses. However, criteria for drug vehicle design rules that can overcome age-specific changes in immune cell functions have yet to be established.ResultsHere, in vivo charge-based nanoparticle (NP) uptake was compared in mice of two age groups (2- and 16-months) within the four notable pulmonary antigen presenting cell (APC) populations: alveolar macrophages (AM), interstitial macrophages (IM), CD103+ dendritic cells (DCs), and CD11b+ DCs. Both macrophage populations exhibited preferential uptake of anionic nanoparticles but showed inverse rates of phagocytosis between the AM and IM populations across age. DC populations demonstrated preferential uptake of cationic nanoparticles, which remarkably did not significantly change in the aged group. Further characterization of cell phenotypes post-NP internalization demonstrated unique surface marker expression and activation levels for each APC population, showcasing heightened DC inflammatory response to NP delivery in the aged group.ConclusionThe age of mice demonstrated significant preferences in the charge-based NP uptake in APCs that differed greatly between macrophages and DCs. Carefully balance of the targeting and activation of specific types of pulmonary APCs will be critical to produce efficient, age-based vaccines for the growing elderly population.Graphical

Integrated Transportation Case: Planning of Future Transport Infrastructure/Connectivity In Dar es Salaam

Urbanization poses significant challenges to transportation systems in rapidly growing cities like Dar es Salaam. This paper examines the potential of Bus Rapid Transit (BRT) and Intelligent Transport Systems (ITS) to address transportation issues in the Ilala municipality. Despite ongoing infrastructure projects, the city lacks a comprehensive master plan to support its projected growth. The research underscores the importance of integrating infrastructure improvements and ITS to optimize the BRT system in Ilala. The study begins with an analysis of the current transportation landscape, highlighting deficiencies in road networks and public transportation that lead to severe congestion and unreliable commutes. Key stakeholders are identified, and the necessity of their involvement in transportation planning is emphasized. The research questions focus on enhancing stakeholder engagement, integrating ITS, and improving road infrastructure design. A mixed-methods approach is employed, including literature reviews, case studies of successful BRT implementations worldwide, and primary data collection through interviews, surveys, and focus groups with various stakeholders. This comprehensive approach provides actionable insights for enhancing urban mobility in Ilala. Future recommendations include upgrading the BRT system to a Level 3 configuration, incorporating elevated BRT sections to separate bus lanes from other traffic, and optimizing the design of lanes, stations, and vehicles to improve efficiency. Additionally, the paper discusses the potential benefits of a well-implemented ITS, providing real-time information to commuters and enhancing overall transportation experience. By addressing these challenges, the research aims to improve the quality of life for Dar es Salaam residents, stimulate economic growth, and contribute to a more sustainable urban environment. The findings and recommendations offer a strategic framework for future transportation planning in Ilala and beyond

Calculation of the main operational characteristics of a tethered high-altitude ship-based system

Objectives. Currently, UAVs are actively used in many military and civilian fields such as object surveillance, telecommunications, radar, photography, video recording, and mapping, etc. The main disadvantage of autonomous UAVs is their limited operating time. The long-term operation of UAVs on ships can be ensured by tethered high-altitude systems in which the power supply of engines and equipment is provided from the onboard energy source through a thin cable tether. This paper aims to select and justify the appearance of such system, as well as to calculate the required performance characteristics.Methods. The study used methods of systemic and functional analysis of tethered system parameters, as well as methods and models of the theory of relations and measurement.Results. The issues of design and implementation of new generation tethered high-altitude ship-based systems were considered. A rational type of aerodynamic design for unmanned aerial vehicles was determined based on existing tethered platforms. The optimal architecture of the tethered system was defined and justified. The paper presents the appearance and solution for placement onboard the ship, and describes its operation. The main initial parameters for designing high-altitude systems such as take-off weight, optimal lift altitude, maximum power required for operation, structure of the energy transfer system, as well as deployment and lift time to the design altitude were selected and calculated.Conclusions. The methodology for calculating the necessary characteristics described in the paper can be used for developing and evaluating tethered high-altitude systems. These systems are capable of performing a wide range of tasks, without requiring a separate storage and launch location, which is especially important in the ship environment. The system presented herein possesses significant advantages over well-known analogues.