This study developed and validated thermodynamic models for 10 kW hydrogen- and ammonia-fueled solid oxide fuel cell (SOFC) systems to investigate the effects of fuel type on system performance, thermal management, efficiency, and exergy characteristics. The developed SOFC stack model was validated against a commercial stack with an average error of less than 10%. The hydrogen-fueled SOFC system achieved a maximum efficiency of 60.0% at 6 kW and 55.39% at 10 kW, whereas the ammonia-fueled SOFC s...

This study explores the application of Conformal cooling channels (CCCs) to reduce warp-age in multilayer thin-shell injection-molded parts while maintaining mold strength. Using a hard disk deflector as a case study, five CCC diameters (0.6–1.4 mm) were analyzed through mold flow and structural simulations. Results show that CCCs effectively reduce warpage to within 0.025 mm, with 0.8 mm and 1.0 mm achieving the lowest warpage of 0.01 mm. Although only the 0.6 mm design meets conventional mold ...

Titanium alloys are commonly used in artificial joint implants due to their excellent mechanical and physical properties; however, long-term implantation can lead to the release of Al and V ions, with vanadium posing toxicity concerns. Titanium alloys also exhibit poor tribological performance, including a high friction coefficient, low wear resistance, and susceptibility to corrosion in body fluids, which can accelerate surface degradation and ultimately contribute to implant failure. In this...

Thermal management is a key barrier to the safe operation of electro-hydrostatic actuators in hypersonic aircraft, where severe aerodynamic heating and time-varying actuation loads can drive permanent-magnet motor temperatures toward critical limits. To address excessive temperature rise, this paper proposes a novel integrated axial Z-shaped liquid cooling channel for the electro-hydrostatic actuator motor housing to enhance heat dissipation performance. A comprehensive mathematical model is est...

Gravity-induced contact between the drill string and the wellbore during directional drilling of long horizontal wells results in significant weight-on-bit (WOB) loss. To address this issue, this paper builds upon previous research and proposes an anti-sticking controller for directional wells. The working principle of the controller is introduced, and experimental studies are conducted to determine the effect of driving speed on the tool state under different flow rates. A coupled dynamic model...

With the more complex downhole conditions, stuck drilling often occurs in downhole drilling system. In order to quickly deal with the stuck drilling accident and resume drilling operation, this study proposes an up-and-down integrated hydraulic jar while drilling. Theoretical analysis is conducted on the collision force based on its working characteristics, and motion simulation analysis of the jar couple is carried out. The dynamic characteristics of the drill string system are determined by es...

Under the technical background of static push vertical drilling tool, the design targeted at its key component - the annular disc valve is carried out. According to the friction force calculation of the disc valve, it is considered to design the valve seat structure in the form of a convex platform. Based on the finite element analysis, the clearance between the upper and lower plate valves and the height of the valve seat convex platform are determined. The annular valve structure and its flow ...

In centrifuge speed control, the gain coefficients of the PID controller (Proportional-Integral-Derivative controller) directly affect control performance and efficiency. Traditional parameter tuning relies on experience and trial-and-error, making it difficult to obtain optimal settings. To overcome this, an RT-PID-IAGA (Real-Time PID optimization based on Improved Adaptive Genetic Algorithm) is proposed. The method constructs a multi-objective fitness function considering speed error, overshoo...

One goal of this research is to find better ways to extrapolate and compute the tails of distributions of sea state parameters. In order to achieve this goal, this paper suggests using a Kernel Density Estimation (KDE) transformation method. The main findings are provided below. The method is applied to forecast the probability distribution tails of four ocean wave datasets measured at three National Data Buoy Center Stations. When compared to the parametric method's prediction results, the sugg...

When predicting the fatigue life of the flexspline in a harmonic reducer using the simulation results from the dynamic numerical model of the harmonic reducer, it is common practice to simplify the flexible bearing structure significantly for convenience. Additionally, the SN curve of the material, obtained from tests conducted by others, is often directly used for calculations. This increases the likelihood of significant errors in the predicted fatigue life of the flexspline. To address this i...

The present paper presents a 3D numerical analysis of a nanoparticle reinforced crystalline metal using a multi-scale simulation technique: the Multi-scale Discrete Dislocation Plasticity (MDDP). This model couples two length scales: discrete dislocation dynamics (meso) and finite element analysis (continuum). The crystalline metal considered is aluminum and nano-sized SiC particles are used for reinforcement. An attempt is made to understand the change in mechanical properties of metal reinforc...