The initial shear layer thickness of a proper expansion jet is changed by direct numerical simulation (DNS) of a supersonic jet, and the transition structure during jet diffusion by amplification of a helical mode pair (m=±3) is investigated. Numerical results show that a λ-shaped vortex structure was formed at the start of jet diffusion and the strong positive radial velocity was located near the tip of the λ-shaped structure. In the acoustic field, as the shear layer thickness decreases, the time for the vortex structure to become complex decreases., and the compression and expansion regions inside the jet are generated earlier.

In this study, we performed erosion test and observation of colliding jets, including the presence or absence of divergent part and axisymmetric convergent - divergent nozzles with different divergent shapes, in order to clarify the effects of the nozzle divergent part on erosion. When the nozzle has divergent part, the cavitation state changes to a typical periodic state of cloud cavitation. It causes a large amount of erosion, compared with the nozzle without divergent part. As a result of the experiments using nozzles with different divergent angles, the erosion characteristics change depending on the shape of the divergent part. We compared experimentally the appearance of cloud cavitation with the erosion characteristics through the cloud observation and the image analysis.

Washing method with low environmental load is required in recent environmental problems. Water jet washing with enhanced physical action is performed by collision of atomized droplets. However, the atomized droplet loses momentum and slows down. Therefore, it is necessary to consider the appropriate injection pressure and distance from the nozzle. In this study, the behavior of water jet injected from fan nozzle was observed. The diameter and velocity distribution of generated droplets/ligaments were obtained by changing distance from the nozzle and injection pressure. The relationship between atomization and cleaning effect of fan water jet were investigated.

A spool valve for water hydraulics, Aqua Drive System (ADS), which uses tap water, has some rectangular openings at control ports for precise control because of the low viscosity of the water. In the valve, cavitation happens quickly, and it occurs some troubles, e. g. noise and vibration, erosion, degradation of controllability. This study focuses on cavitation behavior and cavitation-related noise and pressure-flow rate characteristics of a rectangular orifice. Jet flow behavior issuing from a rectangular orifice strongly depends on its aspect ratio. So, cavitation could be affected by the aspect ratio. However, there is little knowledge of the relationships between the aspect ratio and cavitation noise or pressure-flow rate. This research investigates the aspect ratio influence on cavitation, noise, and pressure-flow rate characteristics with different pressure conditions. The equivalent diameter of the orifice used in this study is from 0.35 to 1.3mm, and it is based on a product spool valve model. As a result, the cavitation jet behavior changes with the orifice aspect ratio and the ambient pressure. But the noise characteristics show the almost same tendency for different aspect ratio.

A passive noise control technique for the flow-induced noise using a porous material was studied experimentally. The purpose of this study was to decrease the aerodynamic sound using porous material that permeated only sound and clarify that reduction mechanism. In the experiment, flow-induced noises emitted from three types of rectangular cylinders was measured in a low-noise wind tunnel. One cylinder was made of four aluminum plates and others were made of two or three aluminum plates. Measurement results show that the frequency of the distinct tonal noise was different among three cylinders, that frequency was higher for using porous material. It was also found that the sound pressure level of the noise was also different and that of the cylinder using two porous material plates was 25 dB smaller at maximum. Velocity field of the wake of cylinders were examined by the PIV measurement and that showed that time and space scale of separated vortices around cylinder were smaller for using two porous material plates. It is assumed that the change of aerodynamic sound was caused by that change in velocity field. However, changes in the sound pressure level and frequency of the generated sound were small due to the little changes of the velocity field in the wake of the cylinder when only one porous material plate was used.

Recently, many studies have been performed to innovate heat cooling and power generation technologies by effectively using the self-excited vibration of the flag-like objective in a free stream. Therefore, the flow structure and characteristics around the flag in a free stream have been attracting attention and studied. On these backgrounds, an experimental study on the relation between the wake of the flag and the noise and vibration of the flag was performed. In the experiment, simultaneous measurements of the displacement, generated noise, and the velocity profiles of the flag were performed. Results showed that the vibration of the downstream edge of the flag which brought the distinct noise generation was caused by the strong upward or downward flow which occurs periodically in the wake of the flag.

In this study, wind tunnel experiments and computational fluid dynamics simulations were conducted to clarify the effects of cross wind on the aerodynamic noise of a multi-rotor drone’s propellers, with and without shrouds. When the propellers were tested without shrouds, the overall sound pressure level (OASPL) of one propeller increased with increasing wind speed, while the OASPL of the other propeller decreased with increasing wind speed. The OASPL might have decreased with an increase in wind speed because the frequency of interference between the blade tip vortices generated from a blade and the following blade was reduced. This can be caused by enhanced downward advection of the blade tip vortices due to increased air flow into the propeller. It is also possible that the intensity of the interference decreased due to enhanced leeward advection of the blade tip vortices. When the propellers were tested with shrouds, the OASPL of one propeller increased and the OASPL of the other one decreased at low wind speeds of 2.0 m/s and 0 m/s. However, the OASPL of both propellers increased significantly at a high wind speed of 10 m/s. This might be because the presence of the shroud prevents the blade tip vortices from being advected to the leeward side and increases the intensity of interference with the following blades.

Many small hydropower stations, which is run-off river type, use a cross-flow turbine because of its excellent partial load characteristics with low manufacturing cost. So far, there have been various studies to improve the turbine performance. The authors have been developing a new shape cross-flow turbine with a cylindrical cavity and a guide wall to enhance the performance and make the turbine small. This study focuses on noise and vibration generated from the turbine. Suppression of noise and vibration is, of course, essential to enlarge operating condition and reliability improvement. This study aims to elucidate the cause of the turbine vibration and evaluate the relationship with the casing shape. Previous research shows a large pressure fluctuation point at the end of the turbine nozzle's outer wall. The authors measured turbine vibration and elucidated the pressure fluctuation in the turbine by CFD analysis. As a result, the vibration can be reduced by suppressing pressure fluctuation by modifying the nozzle outer wall shape. The runner rotation causes the vibration. Moreover, the clearance between the runner and the casing wall significantly affects the vibration characteristics and the turbine performance.

Many small hydropower stations, which is run-off river type, use a cross-flow turbine because of its excellent partial load characteristics with low manufacturing cost. So far, there have been various studies to improve the turbine performance. The authors have been developing a new shape cross-flow turbine with a cylindrical cavity and a guide wall to enhance the performance and make the turbine small. This study focuses on the interaction of the runner internal flow named cross-flow to a runner shaft. Of course, the design process of the shaft diameter carefully considers mechanical strength performance based on structural mechanics and strength of materials. On the other hand, there is little knowledge of the hydrodynamic interaction between the cross-flow and the shaft. So, the authors investigate the influence of the runner shaft diameter on the hydrodynamic performance. As a result, turbine performance deteriorates as the runner shaft diameter increases and the larger opening of a guide vane. The runner torque decreases by the interaction.

This study aims to elucidate the small propeller turbine performance by attaching the outer ring on the runner vane periphery. The unique shape runner has some advantages; suppressing tip leakage, improving turbine efficiency, and strengthening the runner blade. To get better turbine performance with low cost and short time, the authors try to make the runner for small propeller turbine by additive manufacturing technology. It is almost no limit of shapes of runner and guide vane changed the runner blade shape. So, the authors investigate the turbine performance for five types of ring runner by CFD analysis. As a result, the turbine with a full-width outer ring and airfoil blade shows the best turbine efficiency of 80%. It clarifies the outer ring’s role for the turbine performance and the turbine efficiency of each model. The differential pressure between pressure and suction side of the runner blade becomes maximum in the full ring model. The full width ring runner is effective to surpress the tip leakage and improve the turbine performance.

This study focuses on improving the performance of a newly developed submerged impulse turbine suitable for small hydropower generation in drinking water pipelines. The turbine performance becomes lower for submerged operation due to disk friction on the runner surface and mixing loss by runner blades. Previous research revealed that a pair of a disk placed on both sides of the runner can suppress these losses. But, the turbine performance with torque loss suppression disks is not clarified. Therefore, the authors proposed a nozzle disk that integrates a disk and nozzles and examined the disk's effect on turbine performance. The nozzle disk is placed on the runner inlet side and supplies a jet to the runner. The disk shows a higher torque loss reduction for smaller clearance between the runner and disk. Moreover, the disk can generate multiple water jets with less velocity decay and keep an appropriate jet angle. As a result, the turbine with the nozzle disk shows higher efficiency than the previous research on the submerged impulse turbine.

This study focuses on improving a newly developed submerged impulse turbine suitable for small hydropower generation in drinking water pipelines. The authors have investigated the turbine efficiency, torque loss mechanism, and the torque loss suppression method for high-performance submerged impulse turbine. A previous study proposed the nozzle disk and shows the disk makes torque loss reduce and shows the improvement of submerged impulse turbine performance. This report focuses on how the nozzle exit width, which is mounted on the nozzle disk, on the turbine performance. It is also essential to design the turbine nozzle under various head and flow discharge conditions. The nozzle disk has a nozzle, and the nozzle width is 50%, 70%, and 90% of the blade height. The turbine performance test becomes better for wider nozzle width. It is due to the difference in uniformity of pressure distribution acting on a blade pressure side. The wider nozzle shows impartiality pressure distribution.

Sintered oil-impregnated bearings are made by impregnating lubricating oil into a porous material made by compacting and heat-sintering metal powder. This porous material has countless pores inside that lead to the outside, and thus has excellent oil retention properties. In addition, this bearing is a hydrodynamic bearing, which means that when the shaft rotates in the bearing and a load is applied, pressure is generated by the circulation of the lubricant. Therefore, porous journal bearings do not need to be constantly lubricated like ordinary plain bearings. In addition, because of their low cost and compact size, they are widely used in products that are difficult to maintain, such as audio equipment and home appliances. On the other hand, surface texturing is the regular formation of microscopic shapes on a metal surface. Surface texturing of the inner surface of the journal bearing is an effective countermeasure against this seizure. The lubrication characteristics of journal bearings made of sintered oil-impregnated metal without a texture have been evaluated, and the lubrication characteristics of sintered oil-impregnated metal with a flat texture have been evaluated. However, the lubrication characteristics of journal-type sintered oil-impregnated bearings with texture have not been clarified by experiment or theory. Therefore, the characteristics of a spherical texture on the bearing surface of a sintered oil-impregnated bearing that supports radial loads are clarified by numerical analysis. The effects of the texture parameters such as permeability and spherical texture hole area on the load capacity and frictional force were evaluated, and the following were found.

1.Spherical texturing of sintered oil-impregnated bearings results in a decrease in load capacity and frictional force compared to the case without texturing.

2.As the transmittance is increased, the effect of texture formation is reduced.

A journal bearing is a mechanical element that supports the radial load acting on a rotating shaft by means of a fluid film filled in the gap between the shaft and the bearing. It is known that the stability of the bearing is improved by making it non-circular in shape. However, although the stability of an offset double-arc bearing with a different pad angle is better than that of a circular bearing, the optimum shape has not yet been determined. In this study, the optimum shape was searched for by numerical analysis, and the effects of various parameters on stability were investigated. By combining the preload and offset coefficients, the stability limit speed is increased. In this case, however, the effect of the installation angle on the stability is small.

In our previous work, the overset grid functionality of OpenFOAM (Open-source Field Operation And Manipulation) was applied to simulate the motion of a rigid body in a high-speed flow induced behind a moving shock wave. The result showed that the grid spacing significantly affected the body’s motion. In the present work, we performed numerical simulations of two-dimensional flows around a diamond-shaped aerofoil moving with a Mach number of 1.5 by using the overset grid method implemented in OpenFOAM v1812 in order to investigate the effect of the grid spacing on the aerodynamic force acting on the moving body. Wave drag forces on the diamond-shaped aerofoil were evaluated from the simulations using three grid systems with different grid spacings, and the grid convergence for the evaluated wave drag was systematically studied based on the generalized Richardson extrapolation. It was found that the relative errors of the obtained wave drag forces with respect to its analytical value were less than 1 %, and the wave drag force asymptotically converged to the analytical value with the decrease in the grid spacing.

The two-phase flow simulation module interFoam of OpenFOAM was applied to a flow with a free-surface and the results were discussed. In this study, the flow simulation around a cylinder with a free surface placed perpendicular to the flow and whose upper part protrudes above the water surface was conducted. As a result, we could reproduce the phenomenon peculiar to the supercritical field, where the flow is no longer affected by the downstream flow when the Froude number exceeds 1. In particular, at the Froude number of 0.8, we could reproduce the phenomenon similar to the supercritical field, where the Froude number exceeds 1 at the water depth near the free surface due to the acceleration of the flow passed by the cylinder. At the simulation of a Froude number of 1.0, the flow behind the cylinder was different from the experiment. This is considered due to the low accuracy of capturing changes in the flow such as shock waves in the supercritical field. The behavior of the free surface due to the wettability of the cylinder surface is also considered to have an effect.

This study examines the interlaminar shear strength and self-healing of woven carbon fiber (WCF)/epoxy (EP) laminates and spread carbon fiber (SCF)/WCF/EP laminates experimentally. Self-healing is accomplished by incorporating microcapsules containing a healing agent mixed with a UV fluorescent dye and catalyst within epoxy matrix. The apparent interlaminar shear strength and the healing efficiency of the laminates were evaluated by short beam shear tests. The results showed that apparent shear stress-displacement curves of self-healing SCF/WCF/EP laminates is larger non-linearity than that of self-healing WCF/EP laminates. Though the apparent interlaminar shear strength of self-healing SCF/WCF/EP laminates decreased as the number of SCF prepregs increased between WCF prepregs, the healing efficiency increased.

In this study, we attempted to measure the stress intensity factor of in-plane shear cracks using a stress stethoscope. Using a tensile shear flat plate specimen with the artificial cracks and a 3-axis stress stethoscope, the strain near the crack tip was measured and the KII value was calculated. Furthermore, the possibility of this measurement method was verified by comparing the case of using the conventional 2-axis orthogonal strain gauge and theoretical KII value extrapolated by the results of finite element analysis. As a result, by comparing the KII values of the three methods, we suggested the possibility of this method using a 3-axis stress stethoscope and clarified the scope of its application.

The aim of the present study is to elucidate the possibility of improvement of filler dispersibility and mechanical properties of silica/polypropylene (PP) composite systems with hybridized hydrophilic silica nanofillers with carbon black (CB) particles, silica@CB hybridized fillers. The (silica@CB)/PP composites were fabricated by blending PP with the silica@CB fillers prepared using a type of either high structure CB (HSCB) possessing increased degree of branching of the aggregates of CB primary particles or single sphere-typed low structure CB (LSCB) particles. It was found from the tensile tests of the PP composites that the tensile strength of PP could be increased substantially by adding the silica@HSCB hybridized fillers. Compared to the composite system with silica nanofillers alone, an improvement of silica filler dispersibility and elongation property could be observed in the cases of the (silica@CB)/PP composites, especially, the PP composites with the silica@LSCB hybridized fillers. It was also clarified that a remarkable increment in Charpy impact toughness of PP could be achieved by adding the silica@LSCB fillers. The results obtained in this study implied that shape of CB particles (i.e., structure level of CB) in the silica@CB fillers might be one of the crucial factors exerting an influence on mechanical properties of the PP composites with their hybridized fillers.

Polymer composites with high thermal conductivity offer new possibilities for thermal management in electric systems. The objective this paper is to study the synergetic effect of fillers with different shape and size on the thermal and mechanical properties of polymer composites. Representative volume element (RVE) models with a close-packed structure of plate-like and spherical fillers were obtained, and finite element analysis was performed to evaluate thermal conductivity of polymer composites by using Digimat-FE software. In addition, experimental measurements of the thermal conductivity, viscosity and flexural properties of the manufactured polymer composites were carried out. The results showed that polymer composites with the close-packed structure of plate-like and spherical fillers improved the viscosity and flexural properties while maintaining the thermal conductivity.

This pape discusses feasibility of a non-destructive residual stress analysis method through visualization of local thermal deformation behavior. Reversible and localized thermal deformation in the range from room temperature to about +10°C was applied using an infared spot laser to an aluminum alloy specimen, and the thermal deformation behavior was visualized using an 2-D electronic speckle pattern interferometer. External tensile stress was applied to the specimen to simulate residual stress. The effect of external stress on the local thermal deformation behavior was investigated. The results showed that the thermal contraction in and around the heated area varied depending on the external stress. The strain rate of the heated area within 1s after the heating increased with an increase in external stress. Strain relaxation due to the thermal expansion of the heated part occurs at the surrunding part, and the changes of strain increases with the increase in external stress. Therefore, the resulst indicate the feasibility of the residual stress analysis by visualizing the local thermal deformation behavior.

Glass/Polycarbonate (G/PC) laminated safety glasses, which is bonded by acrylic interlayer (ACIL), is often applied for the viewing port of the machine tools. The viewing port for the machine tools requires impact resistance, transparency, and solvent resistance. The G/PC laminated safety glass has excellent characteristics to satisfy those requirements. Recently, thinner structure and weight saving have been more required for the G/PC laminated safety glass. Impact absorption capacity of the G/PC laminated safety glass is influenced by the mechanical properties of ACIL. In this paper, dynamic mechanical properties of ACIL containing CNFs were investigated and master curves were made by using Williams-Landel-Ferry (WLF) equation based on the Time-Temperature superposition principle. As a result, storage modulus and loss modulus of ACIL with CNFs decreased at inflection region by glass transition compared to those without CNFs. Also, loss tangent curves of ACIL with CNFs shifted towards lower temperature than those without CNFs.

Thermal conductivity and processability of polymer composites with boron nitride (BN) particles has been investigated experimentally. Polymer composites with BN particles were fabricated by using planetary centrifugal mixer. The viscosity of uncured polymer composites was measured by tuning-fork vibration method and the thermal conductivity of cured polymer composites were measured by steady-state method. The effect of BN volume fraction, addition of different reaction diluent and weight fraction of reaction diluent on the thermal conductivity was also discussed. The results showed that increasing BN volume fraction lead to increase in thermal conductivity and viscosity of the composites. Moreover, for the composite with 30vol%BN, addition of SR-8EGS to the polymer matrix lead to increasing thermal conductivity and decreasing viscosity of composites.

This study examines the tensile properties of talc/polypropylene (PP) composites containing small amounts of cellulose nanofibers (CNFs). To form the interface between CNFs and PP, maleic acid polypropylene (MAPP) was filled in the matrix of composites. The surface of CNFs was coated with a hydrophobized agent (HA) that helps CNFs dispersion in PP. Two different length of CNFs were used as fillers (CNF-L have a length of 10μm or above, and diameters of 20nm. CNF-S have a length of about 1μm, and diameters of 20nm). Using twin-screw extruder operating at 150rpm and 200°C, talc/CNF/MAPP/PP composites was prepared by using melt-kneading. Tensile tests were carried out to assess the effect of talc and CNF content on the tensile properties of talc/CNF/MAPP/PP composites. The yield stress of talc/CNF/MAPP/PP composites was improved by 3% by adding a talc content of 10wt% and CNF-S content of 0.5wt%. The failure strain of talc/CNF/MAPP/PP composites was improved by 52% by adding a talc content of 10wt% and C-NFL content of 0.5wt%.

This paper focuses on relative motion behavior in ultrasonic bonding of aluminum alloy and Copper. The relative motion of sheet-shaped bonding materials, bonding tools and peripheral dies are visualized by in-situ observation with a high-speed video camera and image analysis. The bonding phenomenon is discussed based on the relative displacement at the bonding interface, as well as the microstructural evolution. The relative motion between at the bonding interface transitionally changes during the ultrasonic bonding. From the microstructural observation, it has been found that the joint strength is governed by macroscopic-plastic deformation of the aluminum alloy. The plastic deformation induced by the relative motion between the ultrasonic tool and the aluminum alloy sheet contributes the bond formation between Copper sheet, resulting in the high joint strength.

Heat flux measurements of a 1 kW solar simulator owned by our laboratory were carried out using two Gurdon meters, and the measurements were taken at the height of the solar simulator focal point (930 mm from the ground) with a square size of 85 mm x 85 mm. A total of 289 measurement points were measured. The average heat flux per point was 67.43 kW/m2, 98.72 kW/m2, and 132.65 kW/m2. The average heat flux per point was 67.43 kW/m2, 98.72 kW/m2 and 132.65 kW/m2. The heat flux was calculated as the total heat flux of 289 points divided by the area of one grid, and the average heat flux was calculated as the heat flux of an arbitrary scanning area divided by the total grid area. At 100% simulator output, the heat fluxes of 1.14 kW, 0.99 kW, and 0.39 kW were recorded for areas of 85 mm × 85 mm, 65 mm × 65 mm, and 35 mm × 35 mm, respectively, and the average heat fluxes per point were 158.38 kW/m2, 234.41 kW/m2, and 314.97 kW/m2. The highest heat flux was 504.72 kW/m2 . The highest heat flux of 504.72 kW/m2 was recorded. The heat flux at 100% output was almost twice as high as that at 60% output. A numerical analysis of the volumetric receiver was performed to study the air flow, outlet temperature and heat collection in the receiver. The maximum outlet temperature was recorded as 1136 K at 100% simulator output and 754.2 K at 60% output. At a flow rate of 3.0 g/s, the heat collection was 578.9 W at 100% simulator output and 243.7 W at 60% simulator output.

When fuel debris retrieved from the Fukushima Dai-ichi Nuclear Power Plant after a severe accident is stored in a cylindrical vessel, the water contained in the fuel debris is decomposed by radiation and hydrogen gas generates. A technique has been developed to reduce the concentration of hydrogen gas accumulated in the cylindrical vessel with time by using a hydrogen recombination catalyst. In this study, the results of experimental confirmation that the hydrogen concentration in the cylindrical vessel decreases according to the recombination reaction of hydrogen and oxygen by the catalyst were described, and the effectiveness of the cylindrical vessel with the catalyst was quantitatively clarified.

It is estimated that the low-velocity streaks in a wall-bounded turbulence break down by the secondary instability creating smaller vortices. As seen sinuous and varicose modes on the Goertler vortex growing on a concave-wall boundary layer,¨ the two modes of the secondary instability of the streaks are expected. In the recent years, the secondary instability is extracted by inserting low and high-frequency artificial disturbances into wall bounded turbulent flows and using an ensemble-average technique for velocity data. In this study, we attempt to control the secondary instability mode by changing the symmetry of the high-frequency disturbances aligned in the spanwise direction. With the in-phase high-frequency disturbances inserted from the two disturbance holes, the extracted perturbation forms of the spanwise symmetry that seems to be the varicose mode. On the other hand, high-frequency disturbances inserted out of phase extract the axisymmetric perturbation that suggests that the secondary instability of sinuous mode also exists in the actual wall-bounded turbulence. These results show that the secondary instability mode of the streak is successfully controlled by the symmetry of the initial disturbances.

In order to generate electric power by using flow-induced oscillation, Multi-articulated flat plate was invented. It flutters regularly and periodically in the uniform flow. The fluttering characteristics of it in the air flow have been investigated. However those in the water flow were not clarified yet. The water tunnel experiments to clarify the fluttering characteristics of Multi-articulated flat plate were conducted. In this study, 18 flat plates with different length, different width, different thickness and different density were examined. All flat plates, the fluttering frequency increased with increasing flow velocity. Different from the results on the air flow, the fluttering frequency was almost independent thickness and density of the plate. On the other hand, it was depended the width of the plate. Furthermore the non-dimensional number consisting of Strouhal number, Reynolds number, and aspect ratio became constant.

Multi-articulated flat plate was proposed to use the flow-induced oscillation as energy resources. It flutters in a uniform flow periodically, but it is still unknown why it is flutters. It was hypothesized that the fluttering motion of Multi-articulated flat plate was caused by the waving motion generated in the flow. In order to prove it, it would be verified that the frequency, the fluttering mode, and the amplitude distribution of the Multi-articulated flat plate would not vary with the number of joint of it. The frequency and the fluttering mode were measured on the fluttering Multi-articulated flat plates of 3, 4, 5, 6, 7, 8, 11 and 22 axes by the wind tunnel experiments. The fluttering frequency was obtained form the displacement by its fluttering motion. Continuous photos were shot by the digital camera, and the amplitude distribution was obtained by image processing. From the results, although the amplitude distributions were different, the fluttering frequency and fluttering mode of Multi-articulated flat plate was almost same.

In a one-dimensional unsteady heat conduction system of a one-layer solid, there is a heat conduction inverse problem analysis method that evaluates the heat transfer characteristics of the surface from the temperature history of two places inside the solid. The method can be applied to several other conditions. However, when the surface has a different layer such as an oxide film, the heat transfer characteristics of the different layer surface cannot be evaluated. Therefore, based on the existing inverse problem analysis method, we propose a method to evaluate the heat transfer characteristics of the surface of the different layer from the temperature history of two places inside the solid having the different layer on the surface. In this method, the different layer surface temperature is assumed from the different layer backside temperature and heat flux obtained by the existing method. The surface heat transfer characteristics are evaluated by gradually correcting the assumed surface temperature using the backside heat flux obtained by the heat transfer direct problem. As a result, when the interface temperature and heat flux of the two-layer solid with different layers are known, it was confirmed that the different layer surface heat transfer characteristics can be sufficiently evaluated by this proposed method.