Aerospace Areas Research Articles

Lightweight and highly heat-resistant copolymerized polyimide foams for superior thermal insulation and acoustic absorption

The development of lightweight and highly heat-resistant polyimide foams (PIFs) remains a great challenge in areas of aerospace, military ships, transportation, and industries. Herein, a series of lightweight and highly thermal-resistant copolymerized PIFs are successfully fabricated by the “stepwise heating-holding” thermal foaming of the copolymerized polyester ammonium salts (C-PEAS), using 3,3′,4,4′-benzophenone tetracarboxylic acid dianhydride (BTDA) and 2,3,3′,4′-biphenyl tetracarboxylic acid dianhydride (α-BPDA) as codianhydride, and p-phenylenediamine (PDA) as diamine. The introduction of α-BPDA increases the rigidity of PI molecule chains and foamability of C-PEAS, and significantly improves the heat resistance of PIFs. The resultant copolymerized PIFs exhibit ultra-low densities (<10 kg·m-3), excellent heat resistance (Tg ranging from 351.2°C to 405.6°C), and high thermal stability. Moreover, they possess high flame retardancies (LOI>44%) and low thermal conductivities (as low as 0.0463 W·m-1∙K-1 at 20°C and no more than 0.0825 W·m-1∙K-1 at 200°C), demonstrating their excellent thermal insulation properties in a wide temperature range. After the continuous heating at 200°C for 40 min, the upper surface of PIFs present low average temperatures less than 60°C. Additionally, the copolymerized PIFs exhibit remarkable acoustic properties with average acoustic absorption coefficients above 0.6 and noise reduction coefficients (NRC) above 0.3. Therefore, the lightweight and highly heat-resistant copolymerized PIFs show great application potentials in the extreme environments of aerospace, military ships, transportation, and industries.

Performance Comparison and Analysis of Four- and Six-Switch Inverter Controls of BLDC Motor Employing Deep Learning

Robust and effective control of brushless dc (BLDC) motors is paramount in modern-day motion control. The BLDC motor is known for its high speed, high torque, small size, low noise, and equally low maintenance requirements compared to the brushed DC motor. Nowadays, it can be found in the areas of robotics, aerospace, military, and industrial machines, among others. In this paper, two inverter topologies, the threephase six-switch driver circuit (TPSSDC) and the three-phase four-switch driver circuit (TPFSDC), are used to drive and control the speed of the BLDC motor. For the control technique, however, a fitting neural network from the deep learning (DL) toolbox is employed to train and improve the speed performance of the motor. Both TPSSDC and TPFSDC are simulated and tested in MATLAB Simulink, and the resultant output is analyzed graphically and analytically. Graphical observation shows that the TPSSDC control approach is superior in terms of reference tracking and has less ripple, and better rise and settling times when compared to the TPFSDC control approach, however, the TPFDC is considered for its low cost and simple circuitry. Numerically, the TPSSDC also outperforms at 1000 rpm with a 1.685 ms rise time and a 1.420 ms settling time compared to the TPFSDC, which rises at 6.526 ms and settles at 5.237 ms. At 3000 rpm motor speed, the TPSSDC is better, having a rise time of 5.815 ms and settling time of 4.048 ms, when compared to the TPFSDC, which rises at 11.277 ms and settles at 10.067 ms.

Bicharacteristic probability of detection of crack under multi-factor influences using alternating current field measurement technique

Alternating Current Field Measurement (ACFM) technique has been widely used in various fields such as oil & gas, aerospace areas. However, during the detection process, the probability of detection (POD) is influenced by multi-factors such as lift-off height, scanning angle and detection speed. In this paper, a bicharacteristic probability of detection (BPOD) model is developed for quantifying the crack detection reliability using integrated Bx and Bz signals in the ACFM technique. A multidimensional BPOD model is established to study the influence of multiple factors on the detection probability of cracks using ACFM technique. A Bayesian network-based method is proposed to reverse the hierarchical impact weights of influence factors on the BPOD of the ACFM technique. The results show that the BPOD model considering both Bx and Bz response signals can evaluate smaller defects than the conventional POD model. The multiple influencing factors can substantially decrease the BPOD of cracks. The hierarchical impact weights on BPOD for cracks are ranked as follows: lift-off height, detection speed, personnel involved in the detection process and scanning angle. This approach can retrospectively find the potential contributors to the missed detections based on the BPOD.

Preface

We are very pleased to introduce the proceedings of 2023 International Conference on Mechanical, Aerospace and Electronic Systems (MAES 2023). The conference was held from November 24 to 26, 2023, which is co-sponsored by University of Johannesburg, South Africa and University of South Africa, South Africa. MAES provided opportunities for discussions about methods, technologies, systems, and best practices in the different areas of mechanical, aerospace and electronic systems from different places around the world. This conference provides opportunities for the delegates to exchange new ideas and application experiences in hybrid format, to establish business cases or research relations and to find global partners for future collaboration. The proceedings of MAES 2023 cover a range of topics, including, but not limited to applied mechanics, automation, CAD/CAM/CAE, computational fluid dynamics (CFD), aerodynamic’s fundamental concepts, aerodynamics, aerospace robotics and mechatronics, aerospace systems and technology, advances in aeronautics and astronautics, aerospace defense systems, aerospace materials, aerospace propulsion systems, etc. On behalf of the Organizing Committee, a special thanks goes to the keynote speakers that shared their research ideas with us. Thanks are also extended to the authors of the papers selected for presentation and publication. Thanks are as well extended to the paper reviewers and the members of the organizing committee for their contribution and commitment to putting together a conference program that hopefully participants have found beneficial to advance their professional endeavor. List of Conference Committee is available in this pdf.

Evaluating vehicle trafficability on soft ground using wheel force information

In the areas of aerospace and military industry, wheeled vehicles are expected to have the ability of passing various ground surfaces, including lunar soil, sand, marsh, mud flat, etc. This makes vehicle trafficability on soft ground become a very hot research topic. There are very a few difficulties in the present research of vehicle trafficability on soft ground, such as obtaining wheel-ground interaction information, inaccurate identification of soil mechanical characteristics parameters, and single evaluation index. In this paper, a novel approach of evaluating the vehicle trafficability on soft ground using wheel force information is proposed. As parts of the proposed approach, the methods of obtaining wheel force information, identification of soil mechanical characteristics parameters and integated method of trafficability evaluation, are discussed in detail. The proposed approach was validated through a practical test.

GLARE deformation in low-restraint state: Tensile and bending behavior

Fiber metal laminates (FMLs) possess a better weight reduction effect than traditional metal materials due to the coupling properties of heterogeneous materials, showing promise in the areas of aviation and aerospace. At present, the research on FMLs mainly focuses on the deformation properties after curing while the mechanical properties in the low-restraint state, i.e. the laminates are temporarily not cured and are formed under lower constraint stresses, are not studied in detail. Herein, the low-restraint GLARE is taken as a research object and its deformation characteristics and failure mode are studied using uniaxial tensile, bending experiments and numerical simulation in this paper. Moreover, the influence of key parameters, such as temperature, laminate structure and span length, is investigated, as well as the tensile and bending deformation behavior of GLARE in a low-restraint state is obtained. In addition, based on experimental observations, it is found that the low-restraint GLARE produces the phenomenon of interlayer slip, and the interlaminar residual stress is much smaller than the cured laminate, whereas the deformation limit and performance are improved. This paper provides theoretical bases for the in-depth analysis of deformation properties and forming laws of low-restraint GLARE, guiding further applications of laminates.

Effect of 60Coγ ray radiation on electrical properties of SiGe HBTs at low temperatures

In this article, total ionizing dose (TID) irradiation experiments were carried out on germanium-silicon heterojunction bipolar transistors (SiGe HBTs) under different bias and temperature conditions. The electrical performance and noise characteristics of the device were characterized before and after irradiation using a semiconductor parameter analyzer and a 1/f noise test system, respectively. The variation of radiation sensitivity parameters with the TID effect and temperature of the device was obtained, and the mechanism of radiation damage degradation was also identified. Results suggest that the oxide-trap charges and interface states induced by irradiation are the main causes for SiGe HBT electrical parameters degradation. With the decreased temperature, Gummel characteristics and 1/f noise are significantly improved. It's found that oxide-trap charges and interface states generated at 93 K is less than that at 300 K. This work lays the foundation for the application of SiGe HBT in aerospace area.

Preface

This Proceedings presents the written contributions of the participants of 2023 3rd International Conference on Computer, Remote Sensing and Aerospace (CRSA 2023) which took place in the form of virtual conference on ZOOM during July 14th to 16th, 2023 in Osaka, Japan. This was the third version of the annual meetings that began in 2021.The three-day scientific program of the CRSA 2023 consisted of keynote speeches, oral presentations, poster presentations and academic investigation with the participation of delegates from China, Japan, UK, USA, India, Algeria, Morocco, Malaysia, among others. Moreover, the objective of CRSA 2023 was to bring together national and international researchers in order to establish a network of scientific cooperation with a global impact in the areas of computer, remote sensing and aerospace; to promote the exchange of creative ideas and the effective transfer of scientific knowledge, from fundamental research to innovation applied to Internet and aerospace solutions and to advance in the development of new research by means of efficient transference of the knowledge between sectors academia and industry.At the keynote speech part of the Conference, one of our keynote speakers Danilo Vasconcellos Vargas (Kyushu University, Japan) made an address on Adversarial Machine Learning: Is Deep Learning Intelligent? He is currently an Associate Professor at Kyushu University, Visiting Researcher at the University of Tokyo and CEO & Founder of MiraiX. His research interests cover Artificial Intelligence (AI), evolutionary computation, complex adaptive systems, interdisciplinary studies involving or using an AI’s perspective and AI applications. Many of his works were published in prestigious journals such as Evolutionary Computation (MIT Press), IEEE Transactions on Evolutionary Computation and IEEE Transactions of Neural Networks and Learning Systems with press coverage in news magazines such as BBC news. The speakers’ brilliant speeches made the attendees feel like bathing in a feast of knowledge.The Proceedings consists of about 30 contributions that were presented as speeches or presentations at the Conference or as publications in the paper volume. All papers published in this volume of Journal of Physics: Conference Series have been peer reviewed through processes administered by the Proceedings Editors. Reviews were conducted by expert referees to the professional and scientific standards expected of the proceedings journal.The topics of papers collected in this volume cover but are not limited to: High Performance Computing, Neural Networks, Geographic Information System, Aeroelasticity and Structural Dynamics, Manned / Unmanned Aviation, etc.We would like to thank the members of reviewers for their kind assistance in reviewing the papers. We would also extend our best gratitude to the keynote speakers for their invaluable contribution and worthwhile ideas shared in the Conference. Special acknowledgements go to the editors and staff of the Journal of Physics: Conference Series for their hard work in making this volume published.We hope that the series conference of CRSA will be even greater than ever before in the future!The Committee of CRSA 2023List of Committee Member is available in this pdf.

M2STaR: A Multimode Spatio-Temporal Redundancy Design for Fault-Tolerant Coarse-Grained Reconfigurable Architectures

Coarse-grained reconfigurable architectures (CGRAs) can provide both energy efficiency and performance for embedded systems, and thus they are increasingly deployed in the areas of aerospace, automotive engineering, and security where reliability is also a main criterion. However, the state-of-the-art fault-tolerant strategies for CGRAs apply either temporal or spatial scheme, including redundancy, periodic detection, workload balancing, and reconfiguration, failing to exploit the feature of dynamic and partial reconfiguration of CGRAs. Also, vulnerable judging circuits and inflexible mode shifting bottleneck the reliability design of fault-tolerant CGRAs. This paper proposes a novel multi-mode fault-tolerant framework for CGRAs, which combines spatial-redundant data-paths with temporal-redundant voters and thus reduces the vulnerable judging circuits while balancing the performance and reliability. This framework can also enable a changing reliability level at runtime via an online configuration transformation method based on pre-compiled patterns. Within the proposed framework, we systematically searched the design space spanning various combinations of the mainstream schemes with a Markov process model to compare the effectiveness and accordingly selected five points as available modes in our design after comprehensive consideration of fault tolerance and time overhead on CGRA. The framework is comprehensively evaluated on a cycle-accurate CGRA simulator, considering both permanent and transient faults. The experimental results show that the fault coverage rate of single transient faults or permanent faults has increased from 71.74% to 93.84%, which means the fault tolerance of the system has been increased by 31.03% compared with the state-of-the-art methods. There is also a great improvement in mean-time-to-failure (MTTF) and reconfiguration latency over baseline designs.

Orbit Predictions Using KS Elements With Earth’s Flattening

Predicting the orbit of a satellite is a fundamental requirement in many areas of aerospace, such as mission planning, satellite geodesy, re-entry prediction, maneuver planning, collision avoidance, formation flying, etc. For near-Earth orbits, the forces due to the non spherical nature of the Earth and atmospheric drag plays an important role and are mainly responsible to bring the satellite back to the Earth. Thus inclusion of the effect of these perturbing forces becomes important for precise orbit computation of near-Earth orbits. Many transformations have emerged in the literature to stabilize the equations of motion either to reduce the accumulation of local numerical errors or allowing the use of large integration step sizes, or both in the transformed space. One such transformation is known as KS transformation by Kustaanheimo and Stiefel [1], who regularized the nonlinear Kepler equation of motion and reduced it into linear differential equations of a harmonic oscillator of constant frequency. In this paper a detailed analysis is carried out for orbit prediction using KS differential equations by including the non spherical gravitational potential of the Earth as the perturbing force. Earths zonal and tesseral harmonics, which produce bands of constant deviation from the spherical field along lines of latitude and longitude, are included to precisely model the Earth’s gravitational potential. Higher order Earth’s flattening terms are included by utilizing the recurrence relations of associated Legendre polynomial and its derivatives. To know the effectiveness of the theory, the results are compared with the real IRS-1A satellite data and the results of other existing solutions for a long duration of nearly a month time. The comparison shows that the KS method provides one of the most and accurate techniques for orbit prediction available at present.

Three-Dimensional-Printed Carbon Nanotube/Polylactic Acid Composite for Efficient Electromagnetic Interference Shielding.

High-performance electromagnetic interference (EMI) shielding materials with ultralow density and environment-friendly properties are greatly demanded to address electromagnetic radiation pollution. Herein, carbon nanotube/polylactic acid (CNT/PLA) materials with different CNT contents, which exhibit characteristics of light weight, environmental protection and good chemical stability, are fabricated using 3D printing technology, where CNTs are evenly distributed and bind well with PLA. The performances of 3D-printed CNT/PLA composites are improved compared to pure 3D-printed PLA composites, which include mechanical properties, conductive behaviors and electromagnetic interference (EMI) shielding. The EMI shielding effectiveness (SE) of CNT/PLA composites could be improved when the content of CNTs increase. When it reaches 15 wt%, the EMI SE of 3D-printed CNT/PLA composites could get up to 47.1 dB, which shields 99.998% of electromagnetic energy. Meanwhile, the EMI shielding mechanism of 3D-printed CNT/PLA composites is mainly of absorption loss, and it generally accounts for more than 80% of the total shielding loss. These excellent comprehensive performances endow a 3D-printed CNT/PLA composite with great potential for use in industrial and aerospace areas.

Processing and characterization of aluminium reinforced metal matrix composite

Indeed, in the areas of aerospace, maritime, transportation, military, and structural applications, composite plays a crucial role in material science. It is composed of two or more phases that are physically and chemically different. The composite exhibits hybrid properties compared to those of the separate components. Materials that are built on a metal matrix are known as metal matrix composites (MMC). The reinforcing component is typically spread in the matrix or continuous component. MMC focuses primarily on applications that need wear resistance and moderately high strength. Aluminum matrix composite reinforced with (Titanium Carbide) TiC particulate is effectively manufactured among MMCs utilising a modified stir casting technique at five various weight% of TiC particle addition. Weight fractions of 3%, 4%, 5%, 6%, and 7% were used. The presence of TiC in the cast aluminium matrix was discovered by the use of colour optical graphs, XRD, and EDS investigation. The ultimate tensile strength clearly improved as the percentage of TiC addition was raised, as seen by the results of the microhardness and tensile tests at 7% of TiC.

Development of Sustainable High Performance Epoxy Thermosets for Aerospace and Space Applications.

There is an imperative need to find sustainable ways to produce bisphenol A free, high performance thermosets for specific applications such as the space or aerospace areas. In this study, an aromatic tris epoxide, the tris(4-hydroxyphenyl)methane triglycidyl ether (THPMTGE), was selected to generate high crosslinked networks by its copolymerization with anhydrides. Indeed, the prepared thermosets show a gel content (GC) ~99.9% and glass transition values ranged between 167-196 °C. The thermo-mechanical properties examined by DMA analyses reveal the development of very hard materials with E' ~3-3.5 GPa. The thermosets' rigidity was confirmed by Young's moduli values which ranged between 1.25-1.31 GPa, an elongation at break of about 4-5%, and a tensile stress of ~35-45 MPa. The TGA analyses highlight a very good thermal stability, superior to 340 °C. The Limit Oxygen Index (LOI) parameter was also evaluated, showing the development of new materials with good flame retardancy properties.

Artificial intelligence in the digital twins: State of the art, challenges, and future research topics

Advanced computer technologies such as big data, Artificial Intelligence (AI), cloud computing, digital twins, and edge computing have been applied in various fields as digitalization has progressed. To study the status of the application of digital twins in the combination with AI, this paper classifies the applications and prospects of AI in digital twins by studying the research results of the current published literature. We discuss the application status of digital twins in the four areas of aerospace, intelligent manufacturing in production workshops, unmanned vehicles, and smart city transportation, and we review the current challenges and topics that need to be looked forward to in the future. It was found that the integration of digital twins and AI has significant effects in aerospace flight detection simulation, failure warning, aircraft assembly, and even unmanned flight. In the virtual simulation test of automobile autonomous driving, it can save 80% of the time and cost, and the same road conditions reduce the parameter scale of the actual vehicle dynamics model and greatly improve the test accuracy. In the intelligent manufacturing of production workshops, the establishment of a virtual workplace environment can provide timely fault warning, extend the service life of the equipment, and ensure the overall workshop operational safety. In smart city traffic, the real road environment is simulated, and traffic accidents are restored, so that the traffic situation is clear and efficient, and urban traffic management can be carried out quickly and accurately. Finally, we looked forward to the future of digital twins and AI, hoping to provide a reference for future research in related fields.

Constructing conductive network using 1D and 2D conductive fillers in porous poly(aryl ether nitrile) for EMI shielding

Electromagnetic interference shielding materials with high shielding effectiveness, light weight, and good heat resistance are desperately needed in areas of aerospace, aircraft, and automobiles. Herein, lightweight porous composites foams with satisfactory electromagnetic interference shielding effectiveness (EMI SE) and mechanical strength was prepared using 1D, 2D conductive fillers and poly(aryl ether nitrile) (PEN) by adapting non-solvent induced phase separation (NIP). It is found that the introduction of 1D and 2D conductive fillers could interweave to form conductive network more easily than the presence of 2D conductive filler alone. The EMI SE of 25.8 dB could be reached for composite foam with 5 wt% of graphene and 3 wt% of carbon nano tubes (PEN/5G3C) and the EMI shielding is dominated by absorption attenuation, with PEN/5G3C shows absorption ratio near 90% in the X-band range, which is believed to be attributed to the multiple internal reflection and absorption inside the conductive foam. Moreover, the network of fillers could strongly interact with the polymer matrix and enhance the tensile strength of the porous foams. The tensile strength of PEN/5G3C reached 4.14 MPa, which is 218% higher than that of neat PEN foam. Due to the high thermal resistance (Tg of 256.4 °C), low density (< 0.2 g/cm3) and satisfactory EMI SE, the composite foam based on PEN show great potential as the next-generation high-performance EMI shielding materials.

From building to city level dynamic digital Twin: a review from data management perspective

The development of the digital twin (DT) has been focused greatly after the concept was brought from the manufacturing and aerospace areas. In the architectural, engineering, construction and facility management (AEC/FM) sector, DTs are capable of integrating heterogeneous metadata and cutting-edge technologies like artificial intelligence and machine learning to create a dynamic digital environment for various purposes. Although building information modelling (BIM) appears to be a significant contributor to DTs, one of the major limitations for DT development is how to construct and provide a shared data environment for all stakeholders to collaborate throughout the life cycle. Furthermore, as the stakeholders’ requirements range of DTs expands from a single building to multiple buildings and regional/city levels, the information and data management gaps (e.g., BIM and GIS data integration) are more challenging and critical. To address these gaps, this paper aims to 1) review the current data management for building and city level DTs from a technical perspective; 2) summarise their major data management issues from building to city levels based on the review; 3) introduce the concept of city-level Common Data Environment (CDE) that addresses the issues identified above, and discuss the possibilities of developing a CDE for a dynamic city-level DT.

Flexible and Robust Ti3C2Tx/(ANF@FeNi) Composite Films with Outstanding Electromagnetic Interference Shielding and Electrothermal Conversion Performances

Flexible and robust multifunctional electromagnetic interference (EMI) shielding materials are playing an increasingly important role in areas of aerospace, electronic communication, artificial intelligence, and wearable electronic devices. Herein, the magnetic and conductive Ti3C2T x /(ANF@FeNi) EMI shielding composite films are fabricated via in situ growth and vacuum‐assisted filtration methods. The introduction of magnetic FeNi nanoparticles can effectively enhance the electromagnetic recombination losses, leading to improved EMI shielding effectiveness (EMI SE) of the composite films. The obtained Ti3C2T x /(ANF@FeNi) composite films show excellent EMI shielding and electrothermal conversion performances. When the mass fraction of Ti3C2T x and FeNi fillers is 60 wt% and their mass ratio is 4:1, the EMI SE of the composite films (50 μm) reaches 60.7 dB in the X‐band (8.2–12.4 GHz). When a low voltage of 3 V is applied, the surface heating temperature of the composite films quickly reaches 111.2 °C. Moreover, the composite films possess satisfied long‐term heating stability under the constant applied voltage. In addition, the composite films exhibit excellent thermal conductivity and mechanical properties. The thermal conductivity (λ) and thermal diffusivity (α) reach 4.72 W m−1 K−1 and 4.36 mm2 s−1, respectively, and the tensile strength and tensile modulus reach 113.4 MPa and 3.1 GPa, respectively.

Formation Mechanism of Wall Jet Generated by Plasma Actuators in Quiescent Air

Flow control technology using dielectric barrier discharge plasma actuators stimulated by a sinusoidal alternating current (AC) high-voltage power supply has been studied explosively during the last two decades in the aerospace area for promoting the aerodynamics performance of the airplane. For the purposes of uncovering the controlling mechanism and enhancing the control effect of plasma actuators, the formation mechanism of the wall jet produced by plasma actuators in still air is studied by using a high-frequency particle image velocimetry system, a pressure-field microphone, and a high-accuracy phase-lock image freezing Schlieren technique. The discharge of the plasma actuator is mainly involved in the streamer discharge and the glowlike discharge during one sinusoidal AC period. It is found that the acoustic streaming flow generated by the plasma actuator lifts the airflow, and the body force generated by the plasma actuator pushes the airflow, during the streamer discharge stage. In addition, the airflow is drawn by the entrainment and pushed by the induced body force, respectively, during the glowlike discharge stage. Based on the body force and acoustic streaming flow, the influences of the plasma actuator on quiescent air are summarized as lift–push–push behavior.

The development of a high-speed miniature pump with dynamic bearing

Abstract A high-speed miniature pump is proposed for the application in aerospace area, where high efficiency and reliability are expected for the pump under the microgravity operation condition. In this paper, a miniature centrifugal pump with dynamic bearing is selected as the objective for the performance development. The prototype of the miniature pump is manufactured and tested by experiments at the rotational speed of 10,000r/min. The comparison of hydraulic performance near the design operation shows good agreement between the numerical results and experimental data. In order to improve hydraulic performance of the pump, the effects of splitter blades, number of blades, and wrap angle of blades are analyzed numerically. For each operating condition, in order to compare the influence of splitter blades on the performance and the internal flow, the impellers with and without splitter blades are designed respectively. In addition, for the splitter blades, the influence of the splitter blade position and the splitter blade thickness are also investigated. The numerical result shows that the highest efficiency among all the impellers is achieved with the blade number of 5, wrap angle of 160° and with no splitter blades. Moreover, for the impellers with the splitter blades, hydraulic performance of the pump is mainly decided by the main blades, while the splitter blades hardly help to improve the efficiency of the pump. The study is helpful for the further application of the high-speed miniature pump in various societies.

An experimental study on gas and liquid two-phase flow in orientated-type flow channels of proton exchange membrane fuel cells by using a side-view method

Proton exchange membrane fuel cells are widely utilized in the areas of aerospace, military and vehicles. Enhancing the reactant transportation and improving water, heat management can effectively increase the electrochemical reaction rate and power output. Orientated-type flow channels have been proved to be effective on improving mass transporting and enhancing performance. In this study, a flow field plate with transparent observation window, whose channel side wall is designed as transparent side-plates, is fabricated to achieve the side-view observation on liquid movement behaviors inside fuel cells. The visualization results of reactant gas and liquid water generation and flowing behaviors in channel regions are observed through the side direction for the first time. Experimental results infer that: orientated-type flow channels having baffles affect droplet generation, moving and shape in gas flow channels, and higher current densities result in more liquid water generation. The baffle downstream region having sudden expanded region slows down droplet moving, and baffle upstream sides accelerates droplet moving. Moreover, the generated heat of electrochemical reaction cannot satisfy maintaining a higher cell working temperature requirement, and an extra heating procedure is required.