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In this study, a simulation model of the two-stage helical gear pair-rotor-bearing of the main reducer is developed by Adams software. The simulation results show that the noise mainly comes from the resonance of the system and the contribution of the high-speed gear pair is large when the speed is in the range of 0~3 000 r/min. Furthermore, the vibration test of the main reducer and the real vehicle noise test are also conducted. The test results show that the noise of the main reducer increases obviously when the input speed is 2 138.67 r/min, and the corresponding meshing frequency of the gear pair is 605.96 Hz, verifying the simulation results. Finally, the effect of bearing stiffness on the resonance speed distribution is studied, and the optimization measures of the structural stiffness of the system are proposed. After optimization, the vibration amplitude decreases significantly when the speed is in the range of 1 400~2 200 r/min, and the resonance speed shifts to a higher speed. The relative errors between the test results and simulation analysis results are less than 5%, which verifies the Adams simulation results and the optimization measures, and provides some reference for shortening the development cycle of the electric drive axle main reducer and saving research and development costs.

The impact of flow channel design on mass transport and drainage in proton exchange membrane fuel cells (PEMFCs) is significant, thereby influencing the reaction rate. Based on conventional wavy design, this study introduces two novel hybrid zigzag flow channels (asynchronous and synchronous) with both zigzag sidewalls and bottom wall, aiming in further improving mass and heat transfer, as well as drainage capacity to achieve better fuel cell performance. Numerical simulations demonstrate that the net power densities of both asynchronous and synchronous hybrid zigzag channels show a 28.7% and 44.4% improvement at low voltage, respectively. The implementation of the asynchronous hybrid zigzag flow channel has been observed to result in a notable reduction in pressure drop, amounting to 9.2%, while concurrently enhancing power output by 10.7% in comparison to a conventional zigzag channel. Additionally, the novel hybrid zigzag designs improve mass transfer efficiency at high current density and exhibits better temperature distribution uniformity. Moreover, the volume of fluid simulations illustrate that hybrid zigzag channels are highly effective in removing accumulated water, surpassing the straight channel with a drainage rate exceeding 54%, as well as a lower surface liquid coverage. [ABSTRACT FROM AUTHOR]

The optimization of flow channel structures significantly impacts the performance enhancement of proton exchange membrane fuel cells (PEMFCs). In this paper, the influences of the loop radius, inclination angle, and presence of the island in the Tesla valve flow field on the performance of a fuel cell were investigated numerically. The results indicated that increasing the inclination angle and curvature radius of the Tesla valve increased the voltage by 16.3% and 31.1%, respectively, compared to the parallel flow field at 0.8 A/cm2. Elevating the inclination angle amplified the resistance effect exerted by tributaries on the main stream, consequently fostering channel-to-membrane mass transfer. Increasing the curvature radius contributed to a heightened total oxygen concentration, but also led to water accumulation problems. The removal of islands increased the reactant contact area, but also created more dead zones, resulting in an observed improvement compared to the parallel flow field, but only marginal improvements over the basic Tesla flow field. [ABSTRACT FROM AUTHOR]

Herein, mesoporous Zn-doped g-C3N4 wrapped CdIn2S4 microsphere nanostructures were fabricated using a simple hydrothermal route. It is found that the CdIn2S4/Zn–g-C3N4 nanocomposite exhibits the most efficient photocatalytic activity for hydrogen evolution. The photocatalytic activity of the CdIn2S4/Zn–g-C3N4 composite presents the optimum performance for hydrogen evolution of 101.74 μmol h−1, which is ∼10.8 and 7.3 times that of pure g-C3N4 and bare CdIn2S4, respectively. The results of varied characterization such as TEM and XPS demonstrate that a tight heterojunction has been successfully built in CdIn2S4/Zn–g-C3N4 nanocomposites, which is highly favorable to limit the recombination of photogenerated electron–hole pairs. Furthermore, Zn could partially replace the C element in the g-C3N4 framework and enhance the separation of photo-induced electrons and holes. Moreover, the incorporation of Zn-doped g-C3N4 nanosheets with mesoporous features considerably improves the photo-stability of CdIn2S4 microspheres. We hope that these CdIn2S4/Zn–g-C3N4 nanocomposites with the tight heterojunction structure may provide new insight into designing novel photocatalysts with high efficiency and excellent stability. [ABSTRACT FROM AUTHOR]

Well aligned TiO2 nanotube arrays have been synthesized via electrochemical anodization, and Pd-based nanoparticles (NPs) were decorated by electrodeposition with the aid of UV irradiation. A new back-to-back Schottky barrier diode (SBD) was formed by connecting with Ag–(Pd decorated TiO2)–Ti. We found that such an SBD sensor has excellent hydrogen (H2) sensing performances at a working temperature of 80 °C, with a detection limit as low as 1 ppm as well as a quick response time within 10 s at a low bias voltage (0.025 V). I–V curves and electrochemical impedance spectroscopy analysis demonstrate a typical rectification characteristic of SBD as well as a dramatic decrease of the barrier height of SBD during the H2 sensing process. The high H2 sensing performance of a Pd-based NP decorated TiO2 nanotube array film SBD could be attributed to the synergism of the highly ordered nano-porous configurations and the Pd-based NP (with a high catalytic active metallic Pd nanoshell layer) decoration providing the enhancement of H2 spillover effect (and/or electronic sensitization) related redox processes. [ABSTRACT FROM AUTHOR]

To exhaust the potential of energy efficiency and dynamic performance of the dual-motor four-drive powertrain, this study developed a multi-objective real-time optimal energy management strategy considering energy efficiency and flexible torque response. First, a theoretical analysis of energy loss and operating characteristics was performed to elucidate the energy-saving advantages and control challenges of the dual-motor four-drive powertrain. Second, an economic strategy based on the adaptive nonlinear particle swarm optimization (ANLPSO) and optimization freezing tolerance mechanism was devised to realize real-time optimal power distribution. Then, the pre-shifting recognition schedule and gradient torque recovery strategy were developed to achieve flexible torque response during gear shifting. Finally, smooth switching logic was created to assure a seamless transition between the two strategies. Numerous simulation results indicate that compared with the single-motor drive strategy, the proposed strategy can increase energy efficiency by 8.1%, 4.02%, and 9.49% under NEDC, WLTC, and CLTC, respectively. During shifting, the longitudinal acceleration and jerk of the proposed strategy are significantly superior to those of the original strategy, thereby enhancing the vehicle's dynamic performance and ride comfort. The results of the drum experiment validate the efficacy of the proposed method for energy consumption optimization and torque coordination control in the actual vehicle environment. [ABSTRACT FROM AUTHOR]

The development of hybrid technology can effectively solve the problems of the high pollution and energy consumption levels of automobiles. Therefore, an energy consumption prediction and control algorithm for hybrid vehicles based on a minimum equivalent fuel consumption model is proposed. The model's battery power consumption is equivalent to the fuel consumption, and the sum of the engine fuel consumption and the battery equivalent fuel consumption is established as the objective function. By utilizing these factors, an innovative minimum equivalent fuel consumption model was constructed that could be used to measure the energy efficiency of hybrid vehicles. The longitudinal force result of braking force distribution control was obtained, as well as the energy consumption prediction structure of a hybrid electric vehicle. The rolling resistance, air resistance, and climbing resistance of the hybrid electric vehicles were calculated, and the energy consumption control algorithm for hybrid electric vehicles was constructed according to the calculation results. The experimental results indicated that under this research algorithm, the driving energy consumption of hybrid electric vehicles was relatively low and the energy consumption and energy efficiency measurements effectively met the actual demand, and the energy consumption prediction and control results were good. [ABSTRACT FROM AUTHOR]