Browse Topic: Logistics
The turbine hybrid electric propulsion system is an important form of green aviation. Unlike the single form of aviation power scheme, the hybrid energy system is flexible in architecture, uses two or more energy forms, and has diverse energy sources. Under different mission requirements, it needs to meet the requirements of mass balance, energy balance, and power demand, etc. Therefore, The control and distribution management between different energy systems have become the key to hybrid power, and power management technology is one of the key challenges in the development of aviation hybrid power control systems. This paper reviews the current structural forms of aviation turbine hybrid electric propulsion systems, analyzes the current research status of power management technology for aviation hybrid systems, and points out that the online power management method based on optimization is the best power management technology solution for turbine hybrid electric propulsion systems
To explore the impact of guiding and warning visual combination factors at the entrance sections of highway tunnels on drivers’ visual characteristics and driving behavior, this study recruited 16 drivers to conduct on-road vehicle experiments at the entrance sections of the Yunling Tunnel’s left bore (with visual combination factors) and right bore (without visual combination factors). Seven visual characteristics and driving behavior indicators, including pupil diameter and vehicle speed, were collected and statistically analyzed. Representative indicators such as pupil diameter, standard deviation of fixation point position, and vehicle speed were selected to establish a trend surface model of visual characteristics and driving behavior. The results indicate that when driving at the entrance section of the left bore, drivers’ pupil diameter and fixation duration were significantly lower than those at the entrance section of the right bore. With the increase in the sweeping view
With the rapid development of China’s logistics and transportation industry, how to reasonably and efficiently use drones to carry out logistics and distribution business under the background of UAM has become a focus of attention for social enterprises. It is urgent to propose a feasible logistics drone take-off and landing sites layout planning method based on reality. The article first explains the principles and connotations of the layout of logistics unmanned aerial vehicle take-off and landing sites, dividing logistics distribution scenarios into three sub scenarios: urban end of pipe distribution, medical material distribution, and short distance logistics transportation. Then, based on strong constraint conditions, preliminary site selection is carried out for each sub scenario. The HRW-Kmedoids algorithm is used to optimize the site selection points for each sub scenario, and the final site selection and alternative points are obtained. The Huangpu District of Guangzhou is
To meet the requirements for efficient evacuation during tunnel navigation, the pontoon of the tunnel bank wall evacuation channel in a large-scale navigation building is taken as the research object. The water body and water wave are simulated using the coupled Euler-Lagrangian method and the push-plate wave method, respectively. The water boundary is processed using the viscoelastic artificial boundary method, and a simulation analysis model of the pontoon under the combined action of water waves and load is established. The results show that the average relative vertical displacement of the pontoon is basically the same under the condition of water wave and no water waves, but the fluctuation range of the pontoon is larger under the condition of water waves. When there are water waves and different loads, the maximum Mises stress distribution of the pontoon is essentially the same, and both are less than 80 MPa, meeting the strength requirements and demonstrating the rationality of
As acoustic requirements for NVH trim components become increasingly constrained by mass, cost, and sustainability targets, traditional approaches to inner dash design based on spatially averaged Transmission Loss (TL) metrics are reaching their practical limits. In fully built vehicles, the acoustic performance of the inner dash is governed by its global insulation capability but also by strong spatial heterogeneity and its interaction with spatially distributed noise sources such as the power unit, gearbox, and tyre-road excitation. This paper presents a test-based methodology for the spatial optimisation of inner dash acoustic performance using reciprocal holography. By applying a calibrated sound power source within the vehicle cabin and measuring the reciprocal response in the engine bay and wheel-arch regions, a high-resolution spatial Transmission Loss “hologram” of the inner dash is obtained under in-situ conditions. The resulting spatial data enables the identification of
There's a well-known video from San Francisco in 1906 that comes up repeatedly in mobility discussions here in the 21st Century. If you haven't seen A Trip Down Market Street, it depicts the absolute bonkers variety of transportation methods used on Market Street back then: cable cars, horsecars, streetcars, pedestrians, automobiles and more. Past is prologue in a world that is adding scooters, delivery robots and other last-minute delivery vehicles to our streets. At the 2026 New York International Auto Show in April, Honda displayed its latest option in the form of the Fastport eQuad Prototype. The eQuad was originally unveiled at Eurobike 2025 and technically comes from Fastport, a micromobility venture from the Honda New Business Innovation Lab that was established to work on projects with global logistics companies. Jamie Davies, chief of operations for Fastport, called the group a kind of startup within Honda. “Three years ago,” Davies told SAE Media in New York, “a small group
This SAE standard establishes the requirement for suppliers to plan a reliability program that satisfies the following three requirements: a The supplier shall ascertain customer requirements b The supplier shall meet customer requirements c The supplier shall assure that customer requirements have been met
Stricter environmental legislation is driving ever-more-demanding performance targets for gasoline particulate filters (GPFs). This study constructs a multi-scale filtration model based on fractal characteristics, taking into account particle size distribution and particle deposition, to investigate the influence of the microstructure of porous media on GPF performance and analyze the impact of structural parameters on capture efficiency and pressure drop. The results show that: (1) Increasing the wall thickness can improve the capture efficiency and pressure drop, and a thicker wall has a stronger inertial interception capacity for larger particles. (2) A reduction in porosity markedly alters both filtration efficacy and flow pressure drop. For particles in the intermediate size range (0.1-0.5 μm), the capture efficiency of a low-porosity structure is more sensitive to the diffusion deposition of small particles, while the inertial collision efficiency of large particles is higher. (3
Traditional safe-life methodologies for rotorcraft structural components rely on deterministic safety factors to account for uncertainty in loads, material properties, and operational usage. While effective for ensuring safety, these approaches lead to early retirement lives and reduced aircraft availability. This paper presents an updated digital twin-based probabilistic framework for rotorcraft component fatigue life assessment that integrates a probabilistic stress–life (S-N) material model, machine learning-based load estimation from flight data, and Monte Carlo uncertainty propagation. The approach is demonstrated for a critical location on the CH-146 Griffon main rotor yoke. Compared with earlier work, the present study advances the framework through independent validation of the load-estimation model and application to available in-service flight data from multiple mission categories. A probabilistic sensitivity analysis is used to examine the separate and combined effects of
This study evaluates whether a statewide layered medical-drone architecture can improve time-critical EMS logistics in Florida by delivering blood products, AEDs, and critical support devices. We define Time-To-Clinical-Support (TTCS) as the interval from incident recognition to first effective therapy and use Florida EMS benchmark intervals, county-level population and centroid distance data, and p-median hub placement to model system performance. Scenario analysis compares 20-, 40-, and 60-hub deployments and estimates order-of-magnitude effects on AED TTCS and survival gains under explicit assumptions for availability, cruise speed, dispatch overhead, and bystander uptake. The results indicate that a mid-scale network may reduce delay sufficiently to produce meaningful clinical benefit, provided it is integrated with EMS dispatch, medical direction, cold-chain controls, and hurricane-resilient infrastructure. Regulatory pathway constraints, incomplete county-level OHCA data, and
Efforts to increase lift and range capabilities of Mars rotorcraft have determined through comprehensive analysis of chord-scaled rotors that a 6-bladed rotor with a thrust-weighted solidity of 0.3 (high solidity) offers significantly improved thrust and efficiency in a Martian environment. However, while the optimal blade number and thrust-weighted solidity configuration is important, optimization of chord and twist distributions as well as airfoil shape is necessary to fully optimize a rotor. This study utilized the Evolutionary aLgorithm for Iterative Studies of Aeromechanics (ELISA) genetic algorithm to optimize chord and twist distributions in conjunction with Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRADII) analysis and optimized airfoil shape in conjunction with OVERFLOW analysis. This work was conducted under the Mars Exploration Program's High Solidity Testing task and supports both scientific and exploration concepts, such as the Chopper
A velocity potential-based finite state model (VPBFSM) has been developed to analyze an isolated rotor in ground effect. The model represents the ground using mass source distributions and imposes the non-penetration of flow boundary condition at the ground. In this paper, VPBFSM predictions of the inflow distribution are compared with experimental results for full and inclined ground effect cases using a model-scale rotor. The VPBFSM shows good agreement with the experimental results and captures the expected trend of decreasing inflow as the rotor approaches the ground, with a larger reduction on the side closest to the ground. Differences in magnitude are observed, but remain acceptable and are attributed to reduced-order modeling assumptions in the VPBFSM and uncertainty in the experimentally derived inflow measurements.
Ultrasonic welding (UW) provides a rapid and efficient method for joining composite components by inducing resin flow through thermally driven diffusion and crystallization at the bonded interface. However, in the absence of a multiphysics modeling framework or a digital twin approach, current practice still depends on extensive trial-and-error testing to determine key welding parameters such as vibration amplitude, weld time, weld pressure, hold time, and downspeed. While in-situ thermal cameras can monitor surface temperatures, the internal temperature at the bonded interface is often significantly higher, introducing the risk of thermal degradation and inconsistent bond quality. To overcome these limitations, GEM developed a high-fidelity multiphysics model to establish a quantitative relationship between process parameters and the evolving temperature field within welded thermoplastic parts. The model integrates coupled mechanical, thermal, and acoustic physics to simulate high
This paper presents two distinct Lagrangian models developed for efficient rotorcraft inflow prediction: an Extended Vortex Ring Wake (EVRW) model and a Viscous Vortex Particle Method Actuator Disk (VVPM-AD). The EVRW model represents wake vorticity as circular rings with a harmonic distribution of bound circulation, thereby avoiding explicit coordinate-by-coordinate calculations. In contrast, the VVPM-AD discretizes shed vorticity into an independent Lagrangian particle cloud. This formulation naturally captures wake roll-up and viscous effects via a meshless Large Eddy Simulation solver, eliminating the need for empirical core-radius formulations. Validated against experimental data, these separate modeling tracks provide a scalable toolkit that balances computational speed with simulation fidelity.
This study evaluates the capability of Simcenter™ Flightstream™, a viscous surface-vorticity compressible-flow panel method, for predicting aerodynamic performance of rotorcraft configurations. Simulations are performed on the ROBIN-mod7 fuselage, PSP rotor, and combined rotor-fuselage system under conditions consistent with available experimental data. Results are compared against experiments and high-fidelity CFD methods, including DES, URANS, and IBM-ASM. For the isolated fuselage, Simcenter Flightstream accurately captures surface pressure distributions, particularly in attached flow regions. For the isolated rotor, thrust, torque, and figure of merit trends show strong agreement with reference data. In the rotor-fuselage configuration, the solver successfully captures interaction effects and predicts performance within experimental uncertainty. Notably, Simcenter Flightstream achieves these results with one to two orders of magnitude lower computational cost compared to high
A Study was conducted by the Army Science Board (ASB) from January 2015 to October 2015 under the sponsorship of the HQDA G-3/5/7. (Ref.1) The reference task title for the Study was "Army Science and Technology for Army Aviation 2025-2040." As stated in the Terms of Reference (TOR) signed by the Secretary of the Army, the overarching objective of the study was to identify and assess Science and Technology (S&T) enhancements capable of being fielded for Army Aviation Aircraft during 2025-2040 time frame that would: Increase Army Aviation's expeditionary capabilities to support full-spectrum military operations, and reduce its sustainment tails and logistics footprint.
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