This comprehensive study investigates the nuanced aspects of pressurized hydrogen vehicle cylinders during refueling, employing numerical simulation and thermal analysis. The examination encompasses the intricate dynamics influenced by cylinder geometry, mass flow rate variations, and the integration of phase change materials (PCMs). Simulations involving cylinders with diverse length-to-diameter ratios and inlet diameters highlight the impact of these parameters on temperature control. Notably, smaller length-to-diameter ratios prove effective for temperature regulation, while larger inlet diameters mitigate temperature rise. The study further explores the role of varying mass flow rates, revealing that an increasing flow rate during refueling results in the lowest temperature rise. In addition to geometry and mass flow rate considerations, the integration of PCMs is a focal point. Modeling and parametric analysis are employed to assess the feasibility of incorporating these materials. The study contributes valuable insights into optimizing the thermal performance and safety of hydrogen fuel systems. The holistic approach considers the interplay of geometry, mass flow rate dynamics, and the innovative use of PCMs, offering a multifaceted understanding of the factors influencing pressurized hydrogen vehicle cylinders.

In this work, we present a detailed description of a mechatronic modeling and control of a piezoelectric actuator for a scanning tunneling microscopy (STM). Existing work on a piezoelectric actuator in mainly modeled with theoretical process. However, in this paper, we used the bond graph approach. Initially a Bond Graph model of the system is illustrated. The dynamic behavior of piezoelectric actuator and the feedback loop controlling the tip to sample distance is analyzed in detail, including parasitic effects by electrical perturbations. Furthermore, an electronic command has been analyzed and improved for the microscope scanner head; the performance of the system has been modeling by the bond graph methodology the global model is presented and discussed. Under excitation our model has been validated by simulation responses of the system. The simulation results indicate that our goal to optimize the control of piezoelectric motion designed for a scanning tunneling microscope can be realized by using the proposed method.

In this document, we concept a sliding mode control based on the Bond Graph approach, for an active current-distance between the Tip and Sample in our scanning system (STM). However, this work gives a robust model to optimize the displacement of a piezoelectric actuator using in the scanner Head of a scanning tunneling microscope, based on the state equation divided from the Bond Graph approach. In order to control the feedback loop between the tip and the sample, and the internal dynamic behavior of the piezoelectric actuator, for this the Tip-Sample distance was analyzed, including disturbances and parasitic effects of mechanics caused by the movement of the scanner Head. Moreover, we proposed a sliding mode control for our system, the global system was studied and analyzed to use in the digitalization; the performance of the proposed model was detailed and discussed. The simulation under input excitation, show the good results and fast responses in the 20-sim environment, with robust sliding mode command.