In recent years, the risk of physical illness due to heat stroke and heat shock has been increasing in such as the non-steady thermal environment. Therefore, to visualize the risk of the non-steady thermal environment, thermal response of the body should be evaluated from the heat transfer problem by using the thermoregulation model. To adopt the individual effect and include no-steady heat transfer problem, the data assimilation of the thermoregulation model has been performed. By assimilating the measured skin temperature, the feasibility of the data assimilation for the prediction of the body core temperature has been evaluated.

Reactive oxygen species are known to have a great effect on the treatment of diseased parts of living organisms. We propose a method using an atmospheric pressure micro plasma jet by the coaxial double pipe for their generation. This plasma jet is in a thermal nonequilibrium condition, and its condition can be controlled from both electrically and fluid dynamically by adopting the coaxial double pipe structure. It is speculated that this method can generate various reactive oxygen species efficiently and effectively. In this study, we have focused on the generation of active oxygen species, especially OH radicals which have strong oxidizing power. Then, we verified the effectiveness of this method and clarified its characteristics.

In this study, the development of the tele-existence robot arm in which human beings can experience not only the haptic environment but also the thermal (hot/cold) environment was focused on. In this report, the temperature transmission system was actually developed, and the trial operations were conducted. A comparison between reproductivities of two types of thermal control units of wearable device to generate a cold environment was made. For the development of a proper wearable device, it is important to design the configuration of joints of the wearable device so as to allow every motions and postures of an operator without any interruption. A prototype design of a wearable arm device, originated from a collar bone joint, with a novel (111) isometric shoulder configuration, was also introduced.

Ni/ZnO nanowire (NW) catalysts for ammonia cracking are prepared and evaluated for hydrogen production for applications such as fuel cells. NW catalysts are expected to be more durable than conventional nanoparticle catalysts because of their three-dimensional structure that prevents agglomeration. In this study, we introduce a hierarchical structure to the NWs to increase the active surface area. The NW catalysts are prepared by hydrothermally synthesizing ZnO NWs and coating them with Ni.

The objective of this research is to clarify the characteristics of biogas dry reforming to produce H₂. 3D Numerical simulation was performed using COMSOL multiphysics. The effect of initial temperature and inlet gas molar ratio on the characteristics of biogas dry reforming, i.e. the distribution of gas molar concentration, temperature, gas velocity, and pressure in the reactor was investigated. As a result, the highest H₂ production concentration was observed in the case of CH₄ : CO₂ = 1 : 1, which is the ideal stoichiometric condition for the dry reforming reaction. Therefore, it is the most optimum inlet gas molar ratio for the dry reforming process.

The analysis of the three-dimensional current density, concentration, and temperature distribution in solid oxide fuel cell (SOFC) cells and stacks has conventionally required high computational cost. In this study, we measure the current distributions in a planar test cell with segmented electrodes, which are used to construct and verify a three-dimensional finite element (FE) model. A surrogate model is generated with machine learning using current densities for the cell voltages, gas concentrations, and temperatures as training data predicted from the FE model, which is expected to reduce the computational cost.

In porous anodes of solid oxide fuel cells, there exists a pressure gradient and a concentration gradient, particularly in the thickness direction. Permeability, a property for pressure-driven gas transport, is closely related to the pore structure. It also depends on the permeation gas in the case of systems with a large Knudsen number, such as porous anodes. However, the effect of the gas species on permeability has yet to be clarified sufficiently. Therefore, gas-species dependence of permeation was experimentally and numerically investigated. Permeability measurements using multiple gases show that the correlation between the permeability and the mean free path of the gas molecules is linear. 3D numerical simulation shows that the permeation flow for each gas is kinematically similar, and its absolute flow rate depends on the physical properties of the permeation gas.

Direct local current and temperature measurements were performed in a planar solid oxide electrolysis cell (SOEC) by segmenting the anode (oxygen electrode) to measure the actual spatial current and temperature distributions for high temperature steam electrolysis along the cathode (hydrogen electrode) flow channels. Under voltage control, the currents and temperatures in the upstream, midstream, and downstream segments along the reactant vapor flow were successfully measured.

CO₂ electrolysis in solid oxide electrolysis cells (SOECs) has attracted much attention. However, there is a problem that CO₂ oxidizes Ni, which serves as a catalyst, resulting in degradation of cell performance. In this study, the cathode surface was analyzed by XAFS. We performed XAFS analysis of electrode surface under actual CO₂ environment to reveal the oxidation mechanism. The experiment in the non-electrolysis mode showed Ni was oxidized in the cathode within 10 minutes in a pure CO₂ atmosphere at about 650°C.

A fabrication method of the PEFC ionomer-free catalyst layer (CL) is developed. In the CL, the ionomer is removed, and instead proton-conducting graphene is used. It was confirmed by the previous study that this CL have high power output in the lower Pt range. However, the output characteristics changes varied depending on temperature and humidity during the fabrication process, and the reproducibility is insufficient. This study aims to improve the reproducibility and the power output by examining the fabricating conditions.

Ionomer used in the catalyst layer of polymer electrolyte fuel cells (PEFCs) acts as a transport path for protons, but it also causes resistance in the transport of oxygen. Therefore, ionomer is one of the essential components for achieving high performance PEFC. However, their structure and properties have not been fully elucidated. In this study, we conducted experiments and improved the experimental setup to perform Surface Plasmon Resonance (SPR) measurements on nanoscale ionomer films formed on a substrate. We aimed to carry out these measurements under conditions where film thickness, the surrounding humidity, and temperature were varied.

For cold startup of a polymer electrolyte fuel cell (PEFC), rapid output increase after the temperature rise is a critical issue. This study investigated the effective operating conditions for this issue. In the experiments, an adiabatic cell was used to simulate the temperature rise of the stack. Flooding occurred after the startup from 4 ℃ with the stoichiometry of 2.5, while dehydration occurred after the sub-zero startup and power increase with the cell from -3 ℃ with the stoichiometry of 5.0. These indicate that the flow rates of supply gases largely affect the accumulation of liquid water.

Lithium diffusion in active materials of all-solid-state batteries often shows strong anisotropy because of their layered crystal structure. Therefore, it is important to understand its effect on battery performance to optimize the electrode structure. In this study, a two-dimensional charge/discharge numerical simulation of a graphite anode of a bulk all-solid-state battery is performed. An anisotropic diffusion model is proposed to consider the layered direction in the active material particles. It is found from the numerical analysis that the anisotropic lithium diffusion in the active material can cause non-uniform lithiation of graphite, resulting in reduced battery capacity.

Lithium-air battery attracts great attention because of its high energy density. However, due to the low solubility and diffusivity of oxygen in the electrolyte, oxygen transport to the reaction site of the positive electrode is limited. In this study, we focused on the effects of the porous cathode structure and wettability of the electrolyte on discharge performance, and attempted to increase the effective reaction area in the electrode and reduce oxygen transport resistance. As a result, it was observed that the discharge performance significantly varies depending on the formation of the electrolyte thin film and the partial infiltration of the electrolyte into the porous electrode.

The effects of flow path structure of a redox flow battery on the discharge performance and the current density distribution were investigated. From the current density distribution measurements, it was confirmed that an interdigitated design (IDD) has a very small bias in the current density distribution upstream and downstream, and that the flow rate has a very small effect on the current density distribution in constant voltage operation, as compared with a flow-through design (FTD). The performance analysis showed that this may be due to the larger value of the surface concentration overpotential due to the slower flow velocity in the IDD.

The purpose of this study is to investigate a heat exchange performance of a direct expansion type heat pump when an underground heat exchanger is inserted into a steel pipe pile. The underground heat exchanger is a U-shaped pipe with one copper pipe (outer diameter 4.0 mm, wall thickness 0.8 mm, length 10 m) and two copper pipes (same standard as one side) connected at the bottom. 12 underground heat exchangers are used, and 1.8 kg of R32 is used as the refrigerant. As a result of the experiment, the average coefficient of performance(COP) was 6.7 at the cooling set temperature of 25℃. It became 5.7 at the cooling set temperature of 27℃.

In this study，the cooling performance of a direct-expansion ground source heat pump with an underground heat exchanger placed in the shallow part of the underground was investigated．As a preliminary test，the heat exchanger was inserted into a stainless-steel container filled with water，utilizing an air/refrigerant heat exchanger used in commercial air source heat pumps．Water was poured into the stainless-steel container to ensure performance when the amount of heat radiation taken from the shallow part of the underground was insufficient．The average COP was 2.9 when the set temperature was 24°C．

In the present study, we have developed a two-dimensional velocity vector sensor using two identical hot-wires placed close together and parallel to each other. To clarify the principle of operation of the sensor, we have used the OpenFOAM software and performed numerical analysis of the velocity field around the sensor consisting of the two hot-wires. As a result, it is shown that the thermal boundary layers developing from the close vicinity of each hot-wire can induce the thermal interference between the hot-wire measurements. Thus, a wall-normal velocity component existing in wall turbulent shear flows will affect the output of each hot-wire of the sensor. In the present study, measurement accuracy of the two component velocity fluctuations obtained by the proposed sensor is appraised experimentally using a canonical flat-plate turbulent boundary layer. Then, it was verified that the present velocity sensor can reproduce not only the DNS results but also the experimental ones measured by the standard I- and/or X-type hot-wire probes. A notable advantage of the proposed hot-wire sensor should be that it can be brought closer to the wall than the X-type one.

Direct numerical simulations were performed to investigate the effects of various ribs on heat transfer and mixing at the jet impingement wall. Increasing the number of ribs installed perpendicular to the main flow enhanced mixing in the height direction because the ribs prevented mass transfer along the wall near the jet impingement area. For turbulent heat transfer near the wall, heat transfer suppression at the lower wall was observed when the number of ribs was increased. On the other hand, the area of the top and side surfaces of the ribs increased, but the heat flux at these surfaces decreased, resulting in a minimum total heat transfer at a certain number of ribs.

The protective effects of pressurized argon gas against cell damage during cold storage on a rat heart striated myocytes monolayer were investigated. The cell monolayers incubated in a culture dish for 24 h were prepared as test samples. The samples were pressurized in 0, 0.4, 0.5, or 0.6 MPa in argon gas, and then preserved at 6°C for 24 h. The pressure-dependent cell viability was evaluated using the water-soluble tetrazolium salts assay. The results showed that protective effect in 0.5 and 0.6MPa were higher than that in 0 MPa (no pressurized dissolution of argon gas). And cell viability increased with increasing the argon gas pressure. Therefore, cell damage due to low temperature will be reduced by pressurized dissolution of argon gas in cold storage.

In this study, to evaluate the influence of non-Fourier effects in laser therapy, we conducted the numerical calculation for the human skin tissue with a heat conduction equation that includes for non-Fourier effects．Comparing the numerical model between Fourier and non-Fourier，it was revealed that the temperature change appeared in the early stage of the laser irradiation had different distribution. There was no major difference in the degree of thermal damage between the two.

The time dependence of cell viability from changes in the electrical impedance ratio of monolayer-cultured rat cardiomyocytes stored at cold temperatures was estimated. Because this ratio varies with temperature, the initial value at 0 h of storage time, which is not equilibrated to the storage temperature, is unknown. Therefore, assuming that the time dependence of cell viability and its ratio during cold storage follows a Weibull distribution, we estimated the initial value of cell viability during cold storage (4, 6°C) and compared it with the actual measured cell viability. Results showed that it was possible to have presumed storage time 0 h (initial value) from the electric impedance ratio in each storage time under cold storage of cells.

Background-oriented schlieren (BOS) methods is a non-contact method for visualizing fluid density fields. However, previous studies have not been applied to the visualization of natural convection boundary layers such as those formed on vertically heated walls. In this study, the possibility of the visualizing the density distribution of the natural convection boundary layer around the heating wall using the BOS method was discussed. From the experimental results, the refractive index changes along the heated plate was visualized but the further the adjustment of the camera’s focusing is required.

Natural convection heat transfer is a buoyancy-driven phenomenon in which density differences are caused by temperature. Horizontal convection is one of the heat transfer phenomena. In this study, we analyzed numerical and experimental images of the flow field and frequency analysis of temperature and velocity in order to evaluate temperature and velocity transitions in detail when the Rayleigh number is varied while maintaining the aspect ratio of a rectangular model. From the results, changes in the spatial structure of heat transfer coefficient and velocity fluctuations are discussed.

Responsive polymers that express actuation functions controllable by external stimuli are expected to be deployed in soft robots and soft actuators. In particular, light-responsive polymers can be used for non-contact actuation and remote/local control. In this study, we verify that the photothermal conversion characteristics of the motion induced by infrared light irradiation of an elastomer film containing liquid metal (LM). The first is the study of Marangoni propulsion on the water surface, and the second is the study of the bending motion of polyimide/LM-containing bilayer film in air.

In this research, the screen mesh wick contained in the copper tube container was pre-coated with a silica nanoparticle layer to enhance its capillarity to experimentally investigate its effect to enhance the heat transfer performance. In the experiment, the one end of the heat pipe was heated using a nichrome wire heater and the other end was cooled using saturated boiling pure water. In addition, effects of filling rate and nanofluid on thermal performance of heat pipes using nanoparticle layer as wick were explored. When the screen mesh was coated with the nanoparticle layer, the thermal resistances of BNW1 (bare tube / nanoparticle-coated mesh / pure water/filling ratio15.2%) decreased 39% in comparison with the ordinary heat pipe without nanoparticle layer, the R increased with a decrease in filling rate. On the other hand, the maximum heat transfer rate increased up to 1.48 times, the MHTR decreased with a decrease in filling rate. It was also shown that the heat transfer performances are improved further if the nanofluid is used as the working fluid.

Loop-Heat-Pipes (LHPs) are promising for cooling of electric devices in spacecraft. However, the LHP operation must be shut down in some cases (e.g., lunar rover on cold nights) to avoid overcooling or reduce heater energy consumption. In this study, we placed an electrohydrodynamic (EHD) conduction pump in the liquid line of the LHP, which operates against the normal LHP flow. The pressure generated by the EHD pump overcomes the capillary pressure developed in the evaporator, then LHP operation stops. An EHD conduction pump was developed and evaluated to demonstrate our approach. As a result, the LHP was shutdown successfully when an appropriate high voltage was applied to the EHD pump, and the shutdown continued until applied voltage to EHD pump has decreased.

In order to improve the performance of motors for electric vehicles, it is necessary to optimize the oil cooling method for the coil ends. In the coil-end oil cooling design, thermal fluid simulation is used to obtain guidelines for improving the efficiency and optimizing the cooling. On the other hand, since the coil end has a complicated structure, it is difficult to verify the validity of the simulation method for the actual geometry and search for improvement methods. For the validation, it is reasonable to simplify the situation and obtain the simplified experimental results. In this study, the coil end is imitated by copper heated horizontal rectangular columns, and the temperature distributions are measured when it is cooled with oil. The prediction accuracy of temperature calculated by particle-based method thermal fluid simulation is verified. It is confirmed that the temperature obtained from this experiment is useful.

This study describes the relationship between the counterflow generated inside an electronic device and the performance of a small axial fan. It is known that when a fan is operated under low airflow conditions in an electronic device with high-density mounting, the generated counterflow interferes with mounted components near the fan, causing a reduction in airflow. This paper evaluates the effect of the blockage environment in front of the fan on the airflow rate using an obstacle with an air vent. The relationship between fan performance was verified by visualizing how the counterflow interferes with the components. As a result, it was found that there was no correlation with the performance itself, although the growth of the counterflow was confirmed.

A network consisted of Ag-nanowires (Ag-NWs) will make a transparent and flexible highly conductive films, and can be used in electronic devices and heaters. The electrical current distribution of the Ag-NW network is not uniform and can form hot spots in the area of high-current flow, which have significant impact on the performance and lifetime of the Ag-NW network. In this study, we measured the temperature of the Ag-NW in the Ag-NW network using the thermoreflectance imaging. We derived the contact resistance and current distribution from the temperature distribution based on an inverse problem analysis. The value of the contact resistance was 5.5 3.8 × 10⁵Ω and showed large variance. Based on the probability density distribution of the current distribution, we showed that that the large variance of contact resistance increases the area of high current concentration and hot spots in Ag-NW network.

Since the response delay of uncooled microbolometer infrared cameras is not small, large afterimages occur when taking thermal images of fast-moving objects or rapid temperature changes. In this work, an investigation was performed to compensate the response delay of an uncooled microbolometer to reconstruct thermal images without afterimages. The measurement by opening and closing the optical path with a chopper showed that the response delay can be well approximated by the first-order lag. In addition, it was demonstrated that the lag-free thermal images can almost be restored from the measured thermal images by compensating the delay using the first-order lag time constant.

For some high-power electronic devices such as ceramic resistors, generated heat is transferred to the housing of the electronic equipment through the contact surface, preventing excessive temperature rise of devices. In such cases, estimation of the thermal contact resistance (TCR) between the device and the housing is crucial, since it affects the temperature rise of devices. The TCR is often estimated by using an equation proposed by Tachibana and Sanokawa. The authors, in order to improve the prediction accuracy, have previously proposed a modified equation which includes the function with a diameter of a real contact point that expresses additional thermal resistance generated by a constriction and expansion of heat flow area. In this study, the TCR of uniform contact surface is estimated by giving the diameter of real contact point obtained by measurement surface topography to the modified equation. The obtained TCR is compared with the prediction results by Tachibana-Sanokawa's equation.

In the thermal design of electronic devices, power consumption of electronic components are important values. However, the useful method to estimate the value has not been reported. In our previous report, we suggested that the power consumption can be accurately estimated from the temperature of each semiconductor device, using a thermal resistance matrix obtained by heating them on a printed circuit board. In this study, to evaluate the usefulness of this method, we investigated the effect of thermal interference by simulating boards with different wiring patterns, number of thermal vias, and distance between elements, under forced cooling and natural cooling conditions.

This paper describes partial corrosion shape identification analysis around reinforcement bar for three-dimensional reinforcement concrete model using practical observed temperature on concrete surface. The heat transfer analysis and the corrosion shape identification analysis are respectively performed by the finite element method and the adjoint variable method. In this study, we focus on the thermal testing in the nondestructive testing methods, and the corrosion shape identification analysis is carried out by the observed temperature on concrete surface.

Rigorous humidity control is required in some industrial and research fields because water vapor in the air affects the quality, hygiene, and stable operation of industrial products, foodstuff, and others. In order to identify the source of water vapor and evaluate its inflow and outflow, we have developed a near-infrared imaging system that can determine the temporal and spatial variations of water vapor in an open space. To improve the quality or concentration resolution of water vapor, the wavelength selection and the condition of illumination light are important. Thus, we modified an illumination system in the imaging system and uses two wavelengths for water vapor imaging.

Two-dimensional impinging jet is applied to cooling, dryness and gas wiping widely. But when making the utility industrial, self-induced oscillation in a spout sometimes affects impinging target. In this study, the cross section of two parallel impinging jet was visualized the flow-fields and observed the flow-fields by using Particle Image Velocity (PIV). It’s purpose to find the condition that self-induced oscillation doesn’t happen in this study and analyze the self-induced oscillation of two-dimensional impinging jet and mechanism.

The mechanical balance at the three-phase contact line of nanobubble on convex-concave solid surface with changing the concave of solid surface is investigated using molecular dynamics method. As a result, it was found that nanobubble can be generated in the concave and its occupation can be fixed inside the concave. In addition, the smaller the concave of solid surface, the larger the nanobubble radius and contact angle, but it is not fixed inside the concave of solid surface. Mean stress tensor is negative at the solid-liquid interface and positive within the nanobubble, resulting in a stress difference between inside and outside the nanobubble.

Our study investigated the wetting behavior of water droplet on a chemically heterogeneous surface which was modified by two distinct types of self-assembled monolayer (SAM) molecules with hydrophilic and hydrophobic terminals, resulting in the formation of a soft matter-based surface exhibiting zebra-like stripes pattern. Furthermore, the pinning phenomenon near the contact line is explored.

Latent heat storage systems (LHTES) using phase change material (PCM) have been studied for efficient utilization of thermal energy. On the other hand, the complex shaped Gyroid heat exchanger (Gyroid HX) fabricated by additive manufacturing (AM) has attracted attention for its large specific surface area and high heat transfer performance. This study focuses on the heat transfer performance of Gyroid HX fabricated by a polymer 3D printer when it is used as PCM-HX. The PCM-HX comprises two channels: one filled with PCM and the other with a working fluid. This study aims to investigate the heat storage and heat release characteristics of the Gyroid PCM-HX in comparison with the conventional heat exchanger, i.e., shell and tube heat exchanger (S&T PCM-HX).

In recent years, ice slurries have attracted attention in the field of thermal storage because of their high cooling efficiency and uniformity. Active control of the supercooling state is necessary for stable production of this ice slurry. Matsumoto focused on the effect of surfactants on the suppression of supercooling resolution and proposed a method to control the supercooling state. In this study, we will examine the effect of a mixture of nonionic and anionic surfactant solutions with different molecular diameters and the application of voltage on the average supercooling degree. We also examine the relationship between the amount of adsorption and the average supercooling degree.

Folded-plate roofs are used as roof materials for many large-scale facilities because they are inexpensive and easily constructed. However, in snowy regions in winter, the edges of folded-plate roofs generate large icicles. Great costs are expended to prevent damage caused by falling icicles. This study was conducted using model experiments to clarify the icicle formation mechanism at edges of a folded-plate roof and to elucidate methods of preventing icicle growth without electricity.

Tetra-n-butyl ammonium bromide (TBAB) hydrate has been attracting attentions as a thermal energy storage material because their phase equilibrium temperature is optimal for air-conditioning system. When flowing a TBAB aqueous solution in a cooling pipe, a layer of TBAB hydrate may form in the pipe. Therefore, the growth characteristics of the hydrate layer should be clarified. The objective of this study was to clarify the growth behavior of TBAB hydrates formed on the cooling surface when the TBAB aqueous solution flowing in a rectangular channel is cooled. Experimental results showed that the growth rate of TBAB hydrate is slower than that of ice and that obtained from the Stefan solution.

The aim of this study is to investigate the effect of operating conditions including water content ratio on the particle size of the water phase dispersing in emulsified fuel droplets sprayed from rapid internal mixing injector (RIMI). An experimental apparatus based on immersion method was constructed to collect the emulsified fuel droplets, and capture photographs of water particles. The results showed that the particle size of the dispersed phase decreased rapidly with the increasing velocity of air atomizing emulsified fuel, and then approached a constant value.

Heat exchangers are widely used in various industrial fields, but the behavior of the thermal fluid inside is complex, and there are problems of performance degradation due to pressure loss and stagnation. In this study, we attempted to predict the heat transfer performance of a finned-tube heat exchanger with fins inclined at 45 degrees to the tubes by analysis. The analysis was performed using OpenFOAM's chtMultiRegionFoam to verify the accuracy of the analysis and to investigate convection and pressure loss by comparing the experimental and analytical results.

Radiant tube (hereinafter called “RT”) is a heating facility used in a continuous annealing furnace. One of the problems of RT is to suppress creep deformation of RT under high temperature environment in the furnace. The suppression of the deformation of RT in the gravitational direction is particularly important in the vertical annealing furnace. In this study, the deformation quantity was compared using FEM for RT of the conventional circular shape and RT of the elliptical shape with high rigidity in the gravity direction. In addition, the structure which can relieve the concentration of stress was examined on the support of RT. An elliptical RT with the developed support was introduced into the annealing furnace, and the deformation rate of RT in the gravity direction was recorded for a long time. As the result, the deformation rate of the introduced RT became 1/6 of the conventional RT.

This paper describes the experimental results of Carnot battery system using thermoelectric modules (TEM) and phase change materials (PCM). In this system, TEM is driven as a heat pump to convert electricity into heat which is stored in PCM in the charging mode. Then, electricity is generated by TEM from the temperature difference between the PCM and the heat sink in the discharging mode. The experimental system performed low round-trip efficiency of 0.33%. The effect of thermal properties of PCM on the round-trip efficiency was investigated via Bayesian optimization, showing that the round-trip efficiency can improve by a factor of 1.4 with the best set of the given thermal properties, however it is still below 1%. Further study to clarify the energy loss mechanism is necessary.

In this paper, I consider one dimensional Thermal Conduction Problem by two methods. One method is conventional ordinary Thermal Conduction Equation as one dimension. In there, Temperature is defined as Continuous Scalar Function T(x,t). On the other hand, if we think Thermal Conduction Problems from motion of molecules, then even in one dimension, we cannot think Temperature T(x,t) as one dimensional scalar quantity, but we must think Temperature as a quantity calculated from movements of molecules in a certain little volume ( dV = dx dy dz). So in this paper, I defined Temperature T(x,t) as Tij (x,t) ∈ dV, and consider the diffarence between conventional Thermal Conduction Analysis and Molecular Thermal Conduction Analysis.

Water is used to extinguish fires because of its large heat absorbability. However, much water flows away quickly from the vicinity of the area water sprayed without absorbing much heat due to low viscosity of the water. In some case, although thickening agents are used to increase the viscosity of water, the influence of thickening agents on cooling have not been clarified yet because there are few reports about it. In this study, superabsorbent polymer (SAP) is used as a thickening agent, the influence of it on the cooling of inclined heated wall was investigated.

This paper numerically tests a new method to detect the occurrence of a flashover in a compartment. A system of reduced ordinary differential equations is developed and converted into stochastic differential equations, which are numerically solved. Similar to the classical Semenov theory, the present model predicts a blowoff of temperature in a finite time, i.e., a flashover, when the initial heat release rate exceeds a critical value. A dynamical marker is then defined as an indicator of the occurrence of a flashover. Its value increases significantly before the heat release rate noticeably rises, showing a promising feature as an early warning signal.

In the production process of bio-syngas by thermal input with oxidizing agent (i.e., air) the N₂ component in the syngas generally tends to be 50 vol% or more. That is, bio-syngas (pyrolysis gas) becomes a low combustible fuel and be difficult to handle because both the propagation speed of flame and the calorific value are low. The combustion temperature of the bio-syngas simultaneously decreases. In order to realize a carbon-free society, there is a strong demand for active use of renewable energy, and the number of attempts to use the bio-syngas fuels for boilers and engines is increasing. Therefore, in this study, we aimed to achieve complete combustion and high-intensity combustion even using bio-syngas that was significantly diluted with N₂. As a result, we succeeded in developing a burner that can maintain complete combustion even at CO/H₂/N₂ = 10: 10: 70, and that CO and NOx are simultaneously reduced. In addition, the we clarified the combustion mechanism of bio-syngas with a swirl-throttle burner by numerical simulation.