Kyushu University [Chihiro Inoue (Associate Professor) Faculty of Engineering, Department of Aeronautics and Astronautics]

Chihiro Inoue

Last modified date：2023.06.24

Associate Professor / Department of Aeronautics and Astronautics / Faculty of Engineering

Presentations

1.	Tenshiro Ichimura，Chihiro Inoue, In-Situ Real-Time Measurement of Droplets Dynamics Using a High-Speed Streaming Camera, PSFVIP13, 2022.08, [URL].
2.	Soma Tauchi，Chihiro Inoue, Improvement of Performance Prediction Model by Considering Losses in Bipropellant Thruster, 33rd International Symposium on Space Technology and Science, 2022.03.
3.	Yuki Oishi，Chihiro Inoue, Performance Prediction for Pulse-Firing Bipropellant Thruster by Time-Space Variable Stream Tube Model, 33rd International Symposium on Space Technology and Science, 2022.03.
4.	Taro Kimura，Chihiro Inoue, Analysis on bursting mechanism of carbon steel sparks, ISEM2021, 2021.11.
5.	Chihiro Inoue, Yuki Oishi, Yuto Terauchi, Yu Daimon, Go Fujii and Kaname Kawatsu, Direct Formulation and Quantitative Water-Flow Diagnostic for Bi-Propellant Thruster Performance, AIAA Propulsion Energy, 2020.08.
6.	Kaname Kawatsu, Ai Noumi, Naoki Ishihama, Taiichi Nagata,Chihiro Inoue, Go Fujii, Hiroumi Tani, Yu Daimon, Resilient Redundant Spacecraft GN&C System Fault Detection and Diagnostics, Aerospace Europe Conference 2020, 2020.02.
7.	Hiroaki Yoshida, Chihiro Inoue, Normalized Spray Flux Distribution of High-Speed Planar Air-Blast Atomizer, The 11th Kyushu University-KAIST Symposium on Aerospace Engineering, 2019.12.
8.	Hiroaki Yoshida, Chihiro Inoue, Junya Kouwa, and Mitsunori Itoh, Spray Flux Distribution of High-Speed Planar Air-blast Atomizer, International Congress on Gas Turbine, 2019.11.
9.	Kaname Kawatsu, Yu Daimon, Go Fujii, Ai Noumi, Chihiro Inoue, Yuto Terauchi , System-level Integrated Modeling and Simulation Targeting Space Propulsion System for Design Evaluation and Risk Assessment, International Symposium on Space Technology and Science, 2019.06.
10.	Chihiro INOUE，Taiki WATANABE，and Yuzo INOKUCHI, Fragile Coloration Mechanism of Traditional Japanese Sparkler, Senko-Hanabi, International Symposium on Fireworks, 2019.05.
11.	Chihiro Inoue, Go Fujii, Yu Daimon, Characteristic Velocity Modeling of Bi-Propellant Thrusters, Space Propulsion 2018, 2018.05.
12.	C. Inoue, Y. Izato, A. Miyake, and M. Koshi, Growing Bubble Leading Spark Ramifications in Senko-hanabi, The 6th International Symposium on Energetic Materials and their Applications, 2017.11.
13.	Chihiro Inoue, Go Fujii, Yu Daimon, A Mixing Length Scale of Unlike Impinging Jets, 70th Annual Meeting of the APS Division of Fluid Dynamics, 2017.11.
14.	Chihiro Inoue, Koji Nozaki, Go Fujii, Yu Daimon, Water flow diagnostics for predicting bi-propellant thruster performance, 53rd AIAA/SAE/ASEE Joint Propulsion Conference, 2017, 2017.08, We demonstrate an environmentally friendly and easily handling cold flow diagnostics to determine the value of exhaust velocity c^∗ in bi-propellant thrusters, practically useful prior to the hot firing tests. We employ only water as the simulant liquid, and directly measure the local ratios of mixture and flow rate using a conventional patternator with an absorbance spectrometer. The density ratio mismatching to the real propellants of MON/MMH is able to be reasonably compensated. Combining with the chemical equilibrium analysis, we calculate c^∗ at wide range of injection mixture ratio under several injector configurations. The validity of the framework is quantitatively evidenced by comparing with corresponding hot firing tests. This fact deduces that the mixing states of MON/MMH at firing condition is reproducible by water flow diagnostics under the appropriate conversion technique. We also investigate the c^∗ trend resulting from injection conditions by flow visualizations..
15.	Toshinori Watanabe, Toshihiko Azuma, Seiji Uzawa, Takehiro Himeno, Chihiro Inoue, Unsteady pressure measurement on oscillating blade in transonic flow using fast-response pressure-sensitive paint, ASME Turbo Expo 2017: Turbomachinery Technical Conference and Exposition, GT 2017, 2017.06, A fast-response pressure-sensitive paint (PSP) technique was applied to the measurement of unsteady surface pressure of an oscillating cascade blade in a transonic flow. A linear cascade was used, and its central blade was oscillated in a translational manner. The unsteady pressure distributions of the oscillating blade and two stationary neighbors were measured using the fast-response PSP technique, and the unsteady aerodynamic force on the blade was obtained by integrating the data obtained on the pressures. The measurements made with the PSP technique were compared with those obtained by conventional methods for the purpose of validation. From the results, the PSP technique was revealed to be capable of measuring the unsteady surface pressure, which is used for flutter analysis in transonic conditions..
16.	J. Kouwa, S. Matsuno, C. Inoue, T. Himeno, T. Watanabe, Free-surface Flow Simulation of Unlike-doublet Impinging Jet Atomization, 20th Australasian Fluid Mechanics Conference, AFMC 2006, 2016.01, In liquid-propellant chemical propulsion systems, the liquid fuel and oxidizer are atomized by impinging jet atomization, mixed and combustions will occur due to auto-ignition inside a chamber. It is important for a performance prediction to simulate the primary atomization phenomenon; especially, the local mixture ratio can be used as indicator of thrust performance, so it is useful to evaluate it from numerical simulations. In this research, to predict local mixture ratio distribution downstream from an impingement point, we propose a numerical method for considering bi-liquid and the mixture and install it to CIP-LSM which is a two-phase flow simulation solver with level-set and MARS method as an interfacial tracking method. A new parameter, β, which is defined as the volume fraction of one liquid in the mixed liquid within a cell is introduced and the solver calculates the advection of β, inflow and outflow flux of β to a cell. SMART method is used for the interpolating value in a cell. By validating this solver, we conducted a simple experiment and the same simulation. From the result, the solver can predict the penetrating length of a liquid jet correctly and it is confirmed that the solver can simulate the mixing of liquids. Then we apply this solver to the numerical simulation of impinging jet atomization. From the result, the inclination angle of fan after the impingement in the bi-liquid condition reasonably agrees with the theoretical value. Also, it is seen that the mixture of liquids can be simulated in this result. We validate the numerical method by comparing numerical results with the experimental results with local mass flux and mixture ratio distributions..
17.	Chihiro Inoue, Atsushi Shimizu, Takehiro Himeno, Toshinori Watanabe, Seiji Uzawa, Numerical and experimental investigation on spray flux distribution produced by liquid sheet atomization, ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, GT 2015, 2015.01, Eulerian-Lagrangian hybrid method is implemented for the prediction of liquid atomization phenomena produced by 2 liquid water jets impinging by an angle of 40 deg. in quiet ambient air. To calculate the flow fields with liquid/gas interface, Eulerian analyses are conducted inside a fixed computational grid system. After the atomization occurs, every droplet is converted to a spherical particle. The motion of particles are tracked in Lagrangian form. For the validation of the developed Eulerian-Lagrangian hybrid method, flow visualization by using a high-speed video camera is carried out. To obtain quantitative values of spray characteristics, the liquid mass flux distribution in space is measured by utilizing a patternator. Numerical and experimental results of atomization process and mass flux distribution of spray show a similarity, and thus the developed method is evaluated that it has potential to predict spray characteristics produced by liquid sheet atomization. The developed numerical method can calculate unsteady spray distributions not only at the plane close to the injector but also far downstream. The spray mass flux distribution in the transient state, which is hard to measure by experiment, is demonstrated..
18.	Atsushi Tateishi, Toshinori Watanabe, Takehiro Himeno, Chihiro Inoue, Unsteady flow simulation of leading-edge separation in thinairfoil cascade A modification to turbulence model, ASME Turbo Expo 2015: Turbine Technical Conference and Exposition, GT 2015, 2015.01, Leading edge separation of thin airfoil cascade in subsonic flow at large angle of incidence was simulated by implicit large eddy simulation (ILES) and Reynolds averaged Navier-Stokes (RANS) simulations with various turbulence models. In the ILES simulations with fine grids, the timeaveraged surface pressure qualitatively agreed with the experimental data. The RANS and ILES simulations on the coarse mesh failed to capture a peak of pressure near the leading edge. From spectrum analysis, it was observed that the flow-field was turbulent in the separation bubble. In the failed RANS simulations, the separation bubble was much longer and the turbulence energy near the leading edge was much lower than those in the ILES results. The development of lambdashaped vortex structures and their sudden weakening near the reattachment point was observed in the unsteady simulations. Two possible modifications to existing turbulence models in RANS simulations were proposed based on the comparison of turbulence energy between the ILES and RANS results. It is shown that these modifications improve the bubble length and C_p distributions of RANS simulations, though further validation and modeling are needed for the application to realistic cases..
19.	Atsushi Tateishi, Toshinori Watanabe, Takehiro Himeno, Chihiro Inoue, Multimode flutter analysis of transonic fan using FSI simulation, ASME Turbo Expo 2014: Turbine Technical Conference and Exposition, GT 2014, 2014.01, Fully coupled steady fluid-solid interaction (FSI) and flutter simulations were conducted on a NASA Rotor 67 transonic experimental fan to demonstrate the capability of application for capturing various aeroelastic phenomena in turbomachinery. The effect of blade deformation on the aerodynamic performance was investigated by steady FSI. Aeroelastic modes were determined using the modal identification technique for the vibration of the cascade. The proposed identification method successfully estimated aeroelastic modes without significant uncertainty. Aeroelastic eigenvalues were localized around the structural modes in vacuum forming the "mode family", and there was negligible change in their frequency. The calculated aerodynamic coupling between the structural modes was small. Based on the reconstructed local unsteady aerodynamic force, the major damping sources in the 1F mode family were determined to be the shock motion and supersonic region near the leading edge. From these results, it was confirmed that the developed FSI method was applicable to the analysis of unsteady characteristics of blades in multimode oscillation..
20.	Chihiro Inoue, Toshinori Watanabe, Takehiro Himeno, Seiji Uzawa, Enhancement of impinging atomization by microjet injection, ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT 2013, 2013.12, With increasing focus on environmental effects and the need for fuel diversity in gas turbines, good liquid atomization is increasingly important. It is known that impinging atomization is able to produce fine drops by impingement of fast liquid jets. However, the atomization characteristics deteriorate at lower injection velocities. In this study, for improving atomization characteristics under a wide range of injection velocity, an effective technique is verified utilizing a small amount of gas (microjet) injection. The microjet is supplied from a pressurized reservoir independent of the liquid supply system, and it is injected from the center of the liquid nozzles toward the impingement point. To clarify the flow field and the mechanism of the effectiveness, experimental visualizations and drop size measurements are carried out. It is found that atomization is remarkably promoted when the dynamic pressure of microjet overcomes that of the liquid at the impingement point. By the microjet injection with only 1% of liquid mass flow rate, Sauter mean diameter (SMD) becomes one-tenth of the original SMD. In addition, optimized atomization efficiency is successfully achieved when the dynamic pressure of the microjet is two times that of the liquid at the impingement point..
21.	Takehiro Himeno, Daichi Haba, Katsutoshi Ishikawa, Yutaka Umemura, Chihiro Inoue, Seiji Uzawa, Toshinori Watanabe, Satoshi Nonaka, Experimental investigation on heat exchange and pressure drop enhanced by vertical sloshing, 49th AIAA/ASME/SAE/ASEE Joint PropulsionConference, 2013.09, For the prediction of heat transfer coupled with sloshing in the propellant tanks of launch vehicle, the pressure drop induced by liquid motion in a sub-scale vessel excited in vertical direction was experimentally investigated. The strong correlation between the pressure drop and liquid motion was confirmed in the experiment. The mechanisms enhancing heat transfer were discussed based on the visualization. It was suggested that shear flow and vortices induced by violent motion of liquid should cause the pressure drop in the closed vessel..
22.	Junya Kouwa, Shinsuke Matsuno, Chihiro Inoue, Takehiro Himeno, Toshinori Watanabe, Free-surface flow simulation of impinging jet nozzles for liquid-propellant thrusters, 49th AIAA/ASME/SAE/ASEE Joint PropulsionConference, 2013.09, This paper describes the results obtained by free surface analysis of impinging jet nozzles for a wide range of orifice diameter and jet momentum under non-reactive conditions. The numerical results are compared with experimental results under some conditions. Capability of the present simulation method CIP-LSM to impinging jet atomization is confirmed by comparing the fan-shaped liquid condition after impingement. As a consequence, the present method can simulate the angle of the liquid after the impingement and the impinging modes approximately. The numerical analysis for three sector of simulant thruster is conducted and it is confirmed that interactions between fans are demonstrated..
23.	Chihiro Inoue, Toshinori Watanabe, Takehiro Himeno, Seiji Uzawa, Impinging atomization enhanced by microjet injection - Effect, mechanism and optimization -, 49th AIAA/ASME/SAE/ASEE Joint PropulsionConference, 2013.09, Impinging atomization, which has been widely utilized in liquid rocket propulsion systems, is able to produce fine drops at a rated operation. In contrast, the atomization characteristics deteriorate under off design conditions when injection velocity comes to be slower. In the present study, for improving atomization characteristics at off design conditions, an effective technique is verified utilizing small amount of gas (microjet) injection. The microjet is supplied from a pressurized reservoir and is injected from the center of the liquid nozzles toward the impingement point. To clarify the flow field and the mechanism of the effect, experimental visualizations, drop size measurements and corresponding numerical analyses are carried out. It is elucidated that Sauter Mean Diameter (SMD) becomes one-tenth of the original SMD by the microjet injection with the amount of only 1% of liquid mass flow rate. The dominant non-dimensional number is found to be the ratio of the dynamic pressure (microjet/liquid jet) at the impingement point. The optimized atomization efficiency is achieved when the dynamic pressure ratio is approximately two..
24.	Chihiro Inoue, Toshinori Watanabe, Takehiro Himeno, Seiji Uzawa, Mitsuo Koshi, Consistent theoretical model of mean diameter and size distribution by liquid sheet atomization, ASME Turbo Expo 2012: Turbine Technical Conference and Exposition, GT 2012, 2012.12, A consistent theoretical model is proposed and validated for calculating droplet diameters and size distributions. The model is derived based on the energy conservation law including the surface free energy and the Laplace pressure. Under several hypotheses, the law derives an equation indicating that atomization results from kinetic energy loss. Thus, once the amount of loss is determined, the droplet diameter is able to be calculated without the use of experimental parameters. When the effects of ambient gas are negligible, injection velocity profiles of liquid jets are the essential cause of the reduction of kinetic energy. The minimum Sauter mean diameter produced by liquid sheet atomization is inversely proportional to the injection Weber number when the injection velocity profiles are laminar or turbulent. A non-dimensional distribution function is also derived from the mean diameter model and Nukiyama- Tanasawa's function. The new estimation methods are favorably validated by comparing with corresponding mean diameters and the size distributions, which are experimentally measured under atmospheric pressure..
25.	Takehiro Himeno, Katsutoshi Ishikawa, Yutaka Umemura, Chihiro Inoue, Toshinori Watanabe, Satoshi Nonaka, Yoshihiro Naruo, Yoshifumi Inatani, Kiyoski Kinefuch, Daizo Sugimori, Koichi Okita, Investigation on pressure change induced by cryogenic sloshing, 48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2012, 2012.12, Pressure drops in the non-isothermal sloshing of liquid nitrogen and liquid hydrogen were experimentally investigated. Heat and mass transfer indicated by the pressure change induced by violent sloshing in the cryostat driven by the mechanical exciter were successfully obtained. Based on the visualized image of liquid motion, it was found that splash and wavy surface induced by violent sloshing of liquid should enhance heat transfer around liquid surface and result in pressure drop. It was also suggested that the instability of singlecomponent system with different temperature between the gaseous and liquid phase could make the pressure control more difficult..
26.	Chihiro Inoue, Toshinori Watanabe, Takehiro Himeno, Seiji Uzawa, Mitsuo Koshi, Theoretical prediction of droplet diameters based on energy conservation law, 48th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2012, 2012.12, A theoretical model is proposed and validated for calculating droplet diameters and size distributions. The model is derived based on the energy conservation law including the surface free energy and the Laplace pressure. Under several hypotheses, the law derives an equation indicating that atomization results from kinetic energy loss. Thus, once the amount of loss is determined, the droplet diameter is able to be calculated without the use of experimental parameters. When the effects of ambient gas are negligible, injection velocity profiles of liquid jets are the essential cause of the reduction of kinetic energy. The minimum Sauter mean diameter produced by liquid sheet atomization is inversely proportional to the injection Weber number when the injection velocity profiles are laminar or turbulent. A non-dimensional distribution function is also derived from the mean diameter model and Nukiyama-Tanasawa's function. The new estimation methods are favorably validated by comparing with corresponding mean diameters and the size distributions, which are experimentally measured under atmospheric pressure..
27.	Takehiro Himeno, Daizo Sugimori, Katsutoshi Ishikawa, Yutaka Umemura, Seiji Uzawa, Chihiro Inoue, Toshinori Watanabe, Satoshi Nonaka, Yoshihiro Naruo, Yoshifumi Inatani, Kiyoski Kinefuchi, Ryoma Yamashiro, Toshiki Morito, Koichi Okita, Heat exchange and pressure drop enhanced by sloshing, 47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2011, 2011.12, For the prediction of heat transfer coupled with sloshing phenomena in the propellant tanks of reusable launch vehicle, the pressure drop induced by heat transfer and the dynamic motion of liquid in sub-scale vessels were experimentally observed and numerically investigated. The correlation between the pressure drop and liquid motion was confirmed in the experiment. The mechanisms enhancing heat transfer were discussed based on the computation. It was suggested that splash and wavy surface induced by violent motion of liquid cause the pressure drop in the closed vessel. In addition, as the preliminary investigation, non-isothermal sloshing of liquid nitrogen and liquid hydrogen were successfully visualized and pressure drop depending on the gaseous species was discussed..
28.	Chihiro Inoue, Toshinori Watanabe, Takehiro Hiemno, Seiji Uzawa, Numerical and experimental study on liquid jet atomization at near-field of coaxial type injector, 47th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit 2011, 2011.12, Aiming at elucidating the flow characteristics of liquid jet at a coaxial type injector, experimental visualization and theoretical analysis as well as numerical simulation were carried out. For computing atomization phenomena, a numerical method has been developed, and it was firstly verified through quantitative comparisons with corresponding experiment of pinch off. It was confirmed that the method can compute inertia force, interfacial tension, viscous force and gravity force adequately, all of which generally affect atomization phenomena. Then, it was experimentally confirmed that fast gas flow enhanced atomization of liquid jet. Numerical analysis showed satisfactorily good agreement with corresponding experimental results. When the gaseous injection velocity became slow at constant mass flow rate, the atomization was suppressed, which was coincident with linear stability analysis of two dimensional liquid/gas parallel flow. It was clearly represented that installation of recess enhanced atomization due to straight gas flow guided by the recess. When the fast gas blew close to liquid jet, the amplitude of instability wave grew, and, additionally, impact of gas on liquid resulted in promotion of atomization..
29.	Chihiro Inoue, Toshinori Watanabe, Takehiro Himeno, Seiji Uzawa, Effects of nozzle inner flow on liquid sheet dynamics and primary atomization, 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery 2010, ISROMAC-13, 2010.12, Aiming at elucidating the relationship between injector inner flow, especially injection velocity profiles, and atomization characteristics of liquid sheet, experimental measurement, numerical and theoretical analysis were carried out. Liquid spacial distribution produced by atomization of axisymmetric sheet, which was created by collision of two water jets in opposite direction, was experimentally obtained utilizing paternator. The amplitude of the liquid sheet oscillation was theoretically developed. The numerical results of three dimensional unsteady atomization process through Kelvin-Helmholtz type instability showed qualitative resemblance with corresponding experimental results and theoretical analyses. It was clarified that non-uniform injection velocity profile resulted in velocity distribution with inflection point inside the sheet, thus the sheet became unstable and enhanced atomization. The effect of injection velocity profile on atomization of two dimensional plane jet was also clearly represented..
30.	Chihiro Inoue, Toshinori Watanabe, Takehiro Himeno, Liquid sheet dynamics and primary breakup characteristics at impingement type injector, 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2009.12, Aiming at elucidating the relationship between injection conditions, especially injection velocity profiles, and atomization characteristics of liquid sheet at the impingement type of injector, numerical analysis, experimental observation and theoretical analysis were carried out. For computing atomization phenomena, a numerical method has been developed. The method was verified through quantitative comparisons with corresponding experiment of pinch off. Then experimental and theoretical studies were performed on atomization of axisymmetric liquid sheet, which was produced by collision of two water jets in opposite direction. The numerical results of the atomization process through Kelvin-Helmholtz type of instability showed qualitative resemblance with corresponding theoretical analyses. It was clarified that non-uniform injection velocity profile resulted in velocity distribution with inflection point inside the sheet. Thus the sheet with non-uniform injection velocity profile tended to be unstable and enhanced atomization. The effect of injection velocity profile on atomization at the impingement type injector was also represented..
31.	Chihiro Inoue, Toshinori Watanabe, Takehiro Himeno, Study on atomization process of liquid sheet formed by impinging jets, 44th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit, 2008.12, Aiming at clarifying and quantifying atomization characteristics at impinging jet injector, numerical analysis, experimental observation and theoretical analysis were conducted. For computing atomization phenomena, a numerical method was developed. The method was verified through quantitative comparisons with corresponding experiment of pinch off. Then experimental and theoretical studies were performed on atomization of axisymmetric liquid sheet, which was produced by collision of two water jets in opposite direction, as well as numerical analysis. The numerical results of the atomization process through Kelvin-Helmholtz type of instability showed qualitative resemblance with experimental visualization and theoretical analysis. Finally, atomization characteristics at impinging jet injector were numerically analyzed. Liquid distributions from the injector face plate were quantified, and the dynamic behavior of the liquid sheet was found to affect strongly on liquid distributions at downstream..
32.	Chihiro Inoue, Toshinori Watanabe, Takehiro Himeno, Numerical analysis on dynamics and inner structures of liquid jet in pinch-off, 43rd AIAA/ASME/SAE/ASEE Joint Propulsion Conference, 2007.12, In order to obtain fundamental knowledge of atomization, the three dimensional unsteady phenomena of pinch off were numerically studied by developed method. The numerical results of liquid shapes and velocity distributions were compared with the corresponding experimental ones. They showed satisfactorily good agreement in a qualitative sense. The liquid jet shape, the pressure and velocity distributions, and the inner flow structure were clarified through the comparisons of distinctly different flow fields due to presence or absence of surface tension. The condition of pinch off, which had close correlation with fluid acceleration at injection, was clearly specified. It was observed that the satellite drops were suppressed by large perturbation amplitude..
33.	Chihiro Inoue, Toshinori Watanabe, Takehiro Himeno, Numerical study on flow induced vibration in a rocket engine preburner, AIAA/ASME/SAE/ASEE 42nd Joint Propulsion Conference, 2006.12, In a preburner of liquid rocket engines, some liquid-oxygen (LOX) posts, which introduced oxygen and hydrogen into combustion chamber, experienced severe flow-induced vibration in unsteady hydrogen flow. The mechanism of the vibration has not been fully understood because of the complexity of the flow field. In the present study, a new numerical method was developed to analyze the flow field of hydrogen, whose characteristic properties lie in its non-idealness and compressibility. The unsteady hydrogen flow inside the preburner unit was analyzed to investigate the details of hydrogen flow field as well as the mechanism of LOX post vibration. It was clarified that hydrogen flow inside the manifold was strongly affected by the upstream condition..

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