Masayuki Anyoji - Academia.edu (original) (raw)
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Papers by Masayuki Anyoji
Journal of Visualization, Oct 19, 2014
Transactions of The Japan Society for Aeronautical and Space Sciences, 2020
Transactions of the Japan Society for Aeronautical and Space Sciences, aerospace technology Japan, 2011
Transactions of the Japan Society for Aeronautical and Space Sciences, aerospace technology Japan, 2014
Scientific Reports
Flapping flight of animals has captured the interest of researchers due to their impressive fligh... more Flapping flight of animals has captured the interest of researchers due to their impressive flight capabilities across diverse environments including mountains, oceans, forests, and urban areas. Despite the significant progress made in understanding flapping flight, high-altitude flight as showcased by many migrating animals remains underexplored. At high-altitudes, air density is low, and it is challenging to produce lift. Here we demonstrate a first lift-off of a flapping wing robot in a low-density environment through wing size and motion scaling. Force measurements showed that the lift remained high at 0.14 N despite a 66% reduction of air density from the sea-level condition. The flapping amplitude increased from 148 to 233 degrees, while the pitch amplitude remained nearly constant at 38.2 degrees. The combined effect is that the flapping-wing robot benefited from the angle of attack that is characteristic of flying animals. Our results suggest that it is not a simple increase...
Actuators
In this study, an experimental investigation of separation control using a dielectric barrier dis... more In this study, an experimental investigation of separation control using a dielectric barrier discharge plasma actuator was performed on an NACA0015 airfoil over a wide range of Reynolds numbers, angles of attack, and nondimensional burst frequencies. The range of the Reynolds number was based on a chord length ranging from 2.52 × 105 to 1.008 × 106. A plasma actuator was installed at the leading edge and driven by AC voltage. Burst mode (duty-cycle) actuation was applied, with the nondimensional burst frequency ranging between 0.1–30. The control authority was evaluated using the time-averaged distribution of the pressure coefficient Cp and the calculated value of the lift coefficient Cl. The baseline flow fields were classified into three types: (1) leading-edge separation; (2) trailing-edge separation; and (3) the hysteresis between (1) and (2). The results of the actuated cases show that the control trends clearly depend on the differences in the separation conditions. In leadin...
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2021
In this study, we apply the optical flow method to the time-series shadowgraph images of impingin... more In this study, we apply the optical flow method to the time-series shadowgraph images of impinging jets using a high-speed video camera with high spatial and temporal resolution. This image analysis provides quantitative velocity vector fields in the object space without tracer particles. The analysis results clearly capture the details of the coherent vortex structure and its advection from the shear layer of the free jet. Although the results still leave challenges for the quantitative validation, the results show that this analysis method is effective for understanding the details of the physical phenomenon based on the quantitative values extracted from the shadowgraph images.
AIAA Scitech 2020 Forum, 2020
Cyborg and Bionic Systems, 2021
The importance of actuators that can be integrated with flexible robot structures and mechanisms ... more The importance of actuators that can be integrated with flexible robot structures and mechanisms has increased in recent years with the advance of soft robotics. In particular, electrohydrodynamic (EHD) actuators, which have expandable integrability to adapt to the flexible motion of soft robots, have received much attention in the field of soft robotics. Studies have deepened the understanding of steady states of EHD phenomena but nonsteady states are not well understood. We herein observe the development process of fluid in a microchannel adopting a Schlieren technique with the aid of a high-speed camera. In addition, we analyze the behavior of fluid flow in a microchannel that is designed to have pairs of parallel plate electrodes adopting a computational fluid dynamics technique. Results indicate the importance of considering flow generated by electrostatic energy, which tends to be ignored in constructing and evaluating EHD devices, and by the body force generated by the ion-dr...
The Proceedings of Conference of Kyushu Branch, 2018
The Proceedings of Mechanical Engineering Congress, Japan, 2017
Proceedings of the Eighth International Conference on Engineering Computational Technology
Journal of Visualization, 2014
Shock Waves, 2009
ABSTRACT The fragmentation of solid plates impacted by a high-speed projectile has been studied i... more ABSTRACT The fragmentation of solid plates impacted by a high-speed projectile has been studied intensively in the past. However, the ejection and shattering process of fragmented particles have not been well resolved yet. To simulate the earlier stage of particle ejection, we performed an analogue experiment of the ejection of aluminum spheres attached on a thin aluminum plate in a row and impinged at tis reverse side by a high-spee plastic cylinder of 51 mm in diameter. The ejection of spheres was observed by using a high-speed digital camera and also holographic interefrometry. These image analysis revealed the motion of ejected spheres.
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 2014
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 2011
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 2014
AIAA Journal, 2015
The effects of Reynolds number, Mach number, and gas species (air and CO2) on aerodynamic charact... more The effects of Reynolds number, Mach number, and gas species (air and CO2) on aerodynamic characteristics of a thin flat plate and a NACA 0012-34 airfoil were investigated under low-Reynolds-number (Re=0.43×104 to 4.1×104) and high-subsonic-flow (M=0.1 to 0.6) conditions. In addition to lift and drag measurements by a two-component balance system, the pressure-sensitive paint technique was applied to measure pressure profiles on the model surface. For the flat plate, the Reynolds number moderately affects the lift and drag characteristics because of a simple behavior of the leading-edge separation bubble; the length of the separation bubble increases as the angle of attack increases. By contrast, the Mach number and specific heat ratio contribute little to the aerodynamic performance. For the NACA 0012-34 airfoil, the lift curves are highly dependent on the Reynolds number because of the formation, shift, and burst of the separation bubble, whereas the compressibility affects only the stall characteristic...
Journal of Visualization, Oct 19, 2014
Transactions of The Japan Society for Aeronautical and Space Sciences, 2020
Transactions of the Japan Society for Aeronautical and Space Sciences, aerospace technology Japan, 2011
Transactions of the Japan Society for Aeronautical and Space Sciences, aerospace technology Japan, 2014
Scientific Reports
Flapping flight of animals has captured the interest of researchers due to their impressive fligh... more Flapping flight of animals has captured the interest of researchers due to their impressive flight capabilities across diverse environments including mountains, oceans, forests, and urban areas. Despite the significant progress made in understanding flapping flight, high-altitude flight as showcased by many migrating animals remains underexplored. At high-altitudes, air density is low, and it is challenging to produce lift. Here we demonstrate a first lift-off of a flapping wing robot in a low-density environment through wing size and motion scaling. Force measurements showed that the lift remained high at 0.14 N despite a 66% reduction of air density from the sea-level condition. The flapping amplitude increased from 148 to 233 degrees, while the pitch amplitude remained nearly constant at 38.2 degrees. The combined effect is that the flapping-wing robot benefited from the angle of attack that is characteristic of flying animals. Our results suggest that it is not a simple increase...
Actuators
In this study, an experimental investigation of separation control using a dielectric barrier dis... more In this study, an experimental investigation of separation control using a dielectric barrier discharge plasma actuator was performed on an NACA0015 airfoil over a wide range of Reynolds numbers, angles of attack, and nondimensional burst frequencies. The range of the Reynolds number was based on a chord length ranging from 2.52 × 105 to 1.008 × 106. A plasma actuator was installed at the leading edge and driven by AC voltage. Burst mode (duty-cycle) actuation was applied, with the nondimensional burst frequency ranging between 0.1–30. The control authority was evaluated using the time-averaged distribution of the pressure coefficient Cp and the calculated value of the lift coefficient Cl. The baseline flow fields were classified into three types: (1) leading-edge separation; (2) trailing-edge separation; and (3) the hysteresis between (1) and (2). The results of the actuated cases show that the control trends clearly depend on the differences in the separation conditions. In leadin...
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, 2021
In this study, we apply the optical flow method to the time-series shadowgraph images of impingin... more In this study, we apply the optical flow method to the time-series shadowgraph images of impinging jets using a high-speed video camera with high spatial and temporal resolution. This image analysis provides quantitative velocity vector fields in the object space without tracer particles. The analysis results clearly capture the details of the coherent vortex structure and its advection from the shear layer of the free jet. Although the results still leave challenges for the quantitative validation, the results show that this analysis method is effective for understanding the details of the physical phenomenon based on the quantitative values extracted from the shadowgraph images.
AIAA Scitech 2020 Forum, 2020
Cyborg and Bionic Systems, 2021
The importance of actuators that can be integrated with flexible robot structures and mechanisms ... more The importance of actuators that can be integrated with flexible robot structures and mechanisms has increased in recent years with the advance of soft robotics. In particular, electrohydrodynamic (EHD) actuators, which have expandable integrability to adapt to the flexible motion of soft robots, have received much attention in the field of soft robotics. Studies have deepened the understanding of steady states of EHD phenomena but nonsteady states are not well understood. We herein observe the development process of fluid in a microchannel adopting a Schlieren technique with the aid of a high-speed camera. In addition, we analyze the behavior of fluid flow in a microchannel that is designed to have pairs of parallel plate electrodes adopting a computational fluid dynamics technique. Results indicate the importance of considering flow generated by electrostatic energy, which tends to be ignored in constructing and evaluating EHD devices, and by the body force generated by the ion-dr...
The Proceedings of Conference of Kyushu Branch, 2018
The Proceedings of Mechanical Engineering Congress, Japan, 2017
Proceedings of the Eighth International Conference on Engineering Computational Technology
Journal of Visualization, 2014
Shock Waves, 2009
ABSTRACT The fragmentation of solid plates impacted by a high-speed projectile has been studied i... more ABSTRACT The fragmentation of solid plates impacted by a high-speed projectile has been studied intensively in the past. However, the ejection and shattering process of fragmented particles have not been well resolved yet. To simulate the earlier stage of particle ejection, we performed an analogue experiment of the ejection of aluminum spheres attached on a thin aluminum plate in a row and impinged at tis reverse side by a high-spee plastic cylinder of 51 mm in diameter. The ejection of spheres was observed by using a high-speed digital camera and also holographic interefrometry. These image analysis revealed the motion of ejected spheres.
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 2014
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 2011
TRANSACTIONS OF THE JAPAN SOCIETY FOR AERONAUTICAL AND SPACE SCIENCES, AEROSPACE TECHNOLOGY JAPAN, 2014
AIAA Journal, 2015
The effects of Reynolds number, Mach number, and gas species (air and CO2) on aerodynamic charact... more The effects of Reynolds number, Mach number, and gas species (air and CO2) on aerodynamic characteristics of a thin flat plate and a NACA 0012-34 airfoil were investigated under low-Reynolds-number (Re=0.43×104 to 4.1×104) and high-subsonic-flow (M=0.1 to 0.6) conditions. In addition to lift and drag measurements by a two-component balance system, the pressure-sensitive paint technique was applied to measure pressure profiles on the model surface. For the flat plate, the Reynolds number moderately affects the lift and drag characteristics because of a simple behavior of the leading-edge separation bubble; the length of the separation bubble increases as the angle of attack increases. By contrast, the Mach number and specific heat ratio contribute little to the aerodynamic performance. For the NACA 0012-34 airfoil, the lift curves are highly dependent on the Reynolds number because of the formation, shift, and burst of the separation bubble, whereas the compressibility affects only the stall characteristic...