A gravitation vortex type water turbine is a water turbine which generates power by the gravitational vortex. Although this water turbine can be generated by a low head and a smallness flow, the flow field is a complicated thing which has a free surface. We researched effect of flow rate on performance and hydraulic loss of a gravitation vortex type water turbine having a circular tank using loss analysis. However, effect of flow rate on performance, flow field and hydraulic loss of a gravitation vortex type water turbine having a volute tank has not been elucidated. In this study, we performed the free surface flow analysis of the gravitation vortex type water turbine and investigated performance and flow field. we also applied the loss analysis method proposed in the past to volute tank and examined the causes and mechanisms of the losses. As the results, the following facts were clarified. In the low rotational speed range, the turbine efficiency increased as the flow rate decreased, and in the high rotational speed range, the turbine efficiency increased as the flow rate increased. Also, the hydraulic efficiency coincided with the tendency of turbine efficiency and decreased significantly in the high rotational speed range of medium flow rate. At each flow rate, the tank outlet loss was dominant in each hydraulic loss, followed by the runner loss and the tank loss.

We experimentally and numerically study the flow field in the washing process of a beverage can. In the experiment, water is injected into a transparent can and is visualized with multiple high-speed cameras. The same flow field is numerically simulated by solving the Navier-Stokes eqs. with a VOF method. We vary the can tilt-angle and the flow rate to see their effects on the water flow. The result shows that the injected water first impinges on the bottom of the can and spreads to the side surface of the can as fingering flows. Then, they merge and become a sheet of water, which flows down along the side surface. When the can is tilted, the asymmetry of the flow field enhances the merger of the fingering flows, and thus the sheet of water quickly appears. It reduces the time for the water to flows over the entire surface of the can. The numerical result agrees with the experimentally visualized water motion.

Recently, existence of bulk nanobubbles (Bulk NBs) in water for a long time has been confirmed experimentally, but necessary conditions for their stable existence have not been well understood. Among the various studies on their stable existence, Hong et al. simulated Bulk NBs by applying the periodic boundary conditions (PBC) to one bubble in the computational domain using molecular dynamics (MD) method, and indicated that there is the maximum interbubble distance for the stable existence. Furthermore, the relation between the bubble radius and the maximum interbubble distance was proposed by a simple model. However, in their study, the effect of bubble radius changes due to thermal fluctuation was not considered. In this study, we studied the effect of bubble radius change by thermal fluctuation on the relation between bubble radius and interbubble distance in stable Bulk NBs. In addition, we investigated Bulk NBs in water using MD with partial elimination of PBC and evaluated lifetime of the bubbles. As a result, it was suggested that NBs are harder to exist in the system where the bubble radius is to be changed by the thermal fluctuation, compared to the study by Hong et al. Furthermore, MD simulation partially eliminating PBC showed that the larger bubble grows while the smaller one shrinks due to the effect of thermal fluctuation. Therefore, it was clear that an appropriate elimination of influence of PBC is necessary for a realistic explanation of existence of Bulk NBs in MD simulations.

Polymer electrolyte fuel cells (PEFCs) can produce electricity in low-temperature operation, and the catalyst layer, which is one of the constituent members, is an electrochemical reaction field with a complicated porous structure. Controlling the porous structure of the catalyst layer is one of the challenges to improve the performance of PEFCs. In this study, we focused on inkjet printing technology as a catalyst layer preparation method to elucidate the relationship between the microstructure of the catalyst layer produced using inkjet printing technology and cell performance. A catalyst layer was prepared using an inkjet printer, and the cell performance was examined. The performance of the catalyst layer made by the doctor blade method was also investigated as a comparison. The porous structure of the prepared catalyst layer was also observed. Regardless of the humidification condition, higher performance results were obtained for the catalyst layer prepared by the doctor blade method under the air supply condition and for the catalyst layer prepared by the inkjet printing technology under the oxygen supply condition.

Thermodynamic state of inner core of the earth is very high temperature and high pressure. Its composition is Fe, Ni and light elements. Although the inner core is a solid, its crystallographic structure is still undefined. In present study, to obtain the basic view for this discussion, Ni metal is simulated by molecular dynamics (MD) method under various conditions up to high temperature and high pressure corresponding to the inside of the earth. Thermodynamic quantities, self-diffusion coefficient and radial distribution functions are analyzed by statistical mechanics form simulated time series data. Phase diagram of Ni is obtained as function of temperature and density/pressure under conditions corresponding to the inner of the earth.

HFO(hydrofluoroolefin) refrigerants are drawing worldwide attention as refrigerants that have less impact on global warming than HFC(hydrofluorocarbon) refrigerants. In order to make HFO refrigerants practical, it is necessary to understand the physical properties of the candidate substances. Among them, surface tension is an important parameter in heat transfer. In this study, we calculated the surface tension of the HFO refrigerant R1234yf using the molecular dynamics (MD) simulations. The mean absolute percentage error (MAPE) between simulated surface tension and REFPROP v9.1 data is 38.7% in the calculated temperature range. The relationship between vapor pressure and surface tension, or vapor density and surface tension, is more consistent with REFPROP v9.1 data than that between temperature and surface tension. The MAPE are 8.8% and 14.6%, respectively.

To make polymer electrolyte fuel cells (PEFCs) competitive, it is necessary to achieve the high current density operation and to improve the flooding performance of the cell. Generally, the water produced in a catalyst layer is accumulated in a gas diffusion layer (GDL). Thus, the water transport from the GDL to the channel is important. In this study, to improve the water transport in the GDL, the novel GDL structure which has the hydrophilic and hydrophobic region in the thickness direction was proposed; this was an attempt to accumulate the water in the hydrophilic region near the separator and to transport the water along the rib from the GDL to the channel. To make the GDL structure with hydrophilic/hydrophobic distribution in the thickness direction, Nafion was coated on the hydrophobic GDL with polytetrafluoroethylene (PTFE). The wettability distribution of the GDL was investigated by the measurement of the contact angle and energy dispersive X-ray spectroscopy (EDS) analysis. Finally, the performance of the cell using the GDL with hydrophilic/hydrophobic distribution was evaluated. The result showed that the cell performance under the high current density is improved by the proposed GDL.

Catalyst layers (CLs) are an important component to determine the performance of polymer electrolyte fuel cells (PEFCs). To clarify the relationship between material distribution in the CLs and the cell performance is required. The objective of this study is to fabricate platinum (Pt)-graded CLs by intermittent double nozzle spray and show the effect of Pt distribution on cell performance. The two types of slurries, which contain platinum-supported carbon and carbon black, respectively, were sprayed intermittently to control Pt content in the thickness direction. Two CLs with different Pt slope were fabricated in the present study. One was a CL with positive Pt slope from gas diffusion layer side to a polymer electrolyte membrane side and the other was a CL with negative Pt slope. Performance test using the two CLs was conducted and the CL with positive Pt slope showed a better performance in a low humidity condition.

Equations of fluid dynamics, for example Navier-Stokes’ equation, are based on continuum model of fluid. These days, miniaturization of the machine has been developed to MEMS and μTAS. Actualization of true nanometer size machine is desired in future days. In nanometer scale, the liquid should be treated as discrete model. In present study, flow of LJ liquid around nanometer size body is simulated by molecular dynamics (MD) method for pseudo 3 dimensional model. The purpose of present study is to analyze and to visualize the behavior of nanometer scale flow.

When an object is immersed in a gas in the presence of thermal gradient whose scale is comparable to the molecular mean free path, a tangential Knudsen force can be generated. This thermal force can be exploited to set objects in motion even without the presence of external forces and with nearly frictionless contact1. This paper presents a numerical analysis of novel configurations of surface microstructures shown in Fig.1, that can induce tangential Knudsen forces. As this phenomenon appears in rarefied gas conditions, or when the Knudsen number is not vanishingly small, conventional analyses based on the continuum hypothesis are inadequate and must be treated by the Boltzmann equation rather than the Navier–Stokes equations². In this study, the direct simulation Monte Carlo (DSMC) method is used and performed for different microstructures and different Knudsen numbers. Results show that the tangential Knudsen force varies in each microstructure and in different Knudsen numbers. It is found that certain shapes and geometric parameters induce large tangential Knudsen forces. Furthermore, the mechanism of the tangential Knudsen force is also found to be different depending on the range of the Knudsen number. For Knudsen numbers of Kn < 0.1, i.e., near the continuum limit, the flow in the bulk of the gas caused by thermally driven flows, drags the upper surface through viscous shear, inducing a tangential Knudsen force. However, from the transition flow regime and above, i.e., Kn > 0.1, molecular flow mechanism appear and therefore the mechanism of the tangential Knudsen force cannot be described by viscous flow mechanism alone.

In recent years, the development of contactless droplet manipulation has been attracting attention in chemical and pharmaceutical fields. Most of the existing studies have focused on interactions on unheated liquid pool and on heated/ unheated solid substrate because it is difficult to fully understand the phenomena of droplet transport on heated liquid pool. This study aims to better understand and manipulate self-propelled droplets on a heated liquid pool. In the present study, glycerin (involatile) was used for the heated liquid surface. Acetone and ethanol (both volatile) were used for the droplets. We clearly observed the droplet behavior on the heated liquid pool with the radiation thermometer. The levitated and self-propelled droplet of 2 mm was visualized and quantified by varying the pool temperature. Compared with our experimental data, the vapor layer thickness between a droplet and heated liquid pool, and the velocity of self-propelled droplets were well predicted.

In this study, behavior of fuel film formed by impingement of iso-octane spray injected from a DISI injector and detailed wall temperature change of aluminum and ground quarts surface were investigated. Adhesion behavior of fuel spray and wall temperature change during and after impingement was measured under various initial wall temperature conditions (T₀ = 100°C, 130°C, and 200°C). Formation and evaporation of fuel film were observed by a high speed camera. As a result, fuel film evaporation on the aluminum surface was faster than that of the ground quarts glass surface. Wall temperature drop of the aluminum surface was higher than that of the ground quarts glass at T₀ = 200°C condition.

An atmospheric pressure micro plasma jet is a jet state of low temperature thermal nonequilibrium plasma using a discharge tube nozzle. This plasma jet is applied to various fields such as medical care, and has attracted attention in recent years. The purpose of this study is to apply atmospheric pressure micro plasma jet by rectangular nozzle with three layered structure to synthesis of silicone films. As a method, cyclic siloxane (D5) as a raw material is mixed with helium, and chemical reactions to form film precursors are generated in respective plasma fields generated in three layers in a discharge tube nozzle, and these are jetted onto the target substrate to synthesis a silicone film. In this study, we succeeded in this method and clarified its characteristics.

In this study, we propose a temperature measurement method that uses ultra-fine fluorescent wires. Reynolds number can be made extremely small by making the wire thin, and it is possible to measure without disturbing the air flow. The surface of the wire was coated with fluorescent paint (Rhodamine B, chameleon phosphor). UV light was used as the light source of visualization. Rhodamine B paint illuminates subtle orange fluorescent light and its the brightness changes with the temperature of air. Chameleon phosphor has the property that its color changes depending on the temperature of the air. Single high sensitivity color camera (ISO 25600, 14 bit, 6,000×4,000 pixels) was used to record the visualized image.

The reaction and diffusion phenomenon of HCl and NaOH in the microchannel was visualized.The wavelength to be used for visualization is narrowed down by the stepwise method, and the regression model for performing simultaneous three-component imaging of HCl, NaOH, and NaCl is created by selecting it based on the R-square with corrected degrees of freedom and Variance Inflation Factor (VIF). From the imaged images, it was clarified that the distribution of the solution was visualized in all the components, and the imaging of the three components was possible at the same time.

This paper presents a method for measuring simultaneously non-axisymmetric three-dimensional (3D) temperature and flow fields in water formed by free convection surrounding a 1-mm-diameter heated sphere. This method is based on the temperature dependence of the absorption coefficient of water at a wavelength of 1150 nm. In the experiment, two-dimensional (2D) images of absorbance in two orthogonal directions were acquired. To reconstruct the 3D temperature distribution, we applied a non-axisymmetric Abel inverse transform to the 2D images. In addition, the flow velocity distribution was obtained by using a particle tracking method with the Lucas-Kanade algorithms. The results demonstrated that the evolution of the non-axisymmetric temperature distributions involved with free convection, and the flow velocities and directions reflected circulating flow with an upward plume.

Wall heat flux sensors for the quantitative analysis of the cooling loss in the piston chamber of internal combustion engines have been developed to improve the efficiency of motor vehicles. For the simultaneous detection of the high-speed fluctuation (AC heat flux) and the steady component (DC heat flux), the wall heat flux sensor using thin film RTD and two internal thermocouples (TCs) on the Al alloy substrate is proposed. The proposed analysis method using the sensor can realize the calculation of wall heat flux independent of the attached environment by 2D transient heat transfer analysis with temperature measured at 3 points in the sensor. In this paper, the measurement of the wall heat flux generated by the hot air jet was performed, and the temperature was measured by the surface RTD, internal 2 TCs, and TC in the sensor mounting tube. The experimental investigation of the proposed analysis method using the fabricated sensor was conducted by comparing the result using the 4-point temperature (RTD, 2 internal TCs, and TC in mounting tube) and the 3-point temperature in the sensor substrate. (RTD, 2 internal TCs)

The basic characteristics of a thermal switch that controls the flow of heat by switching on/off the ionic wind is discussed. A heater made of aluminum block maintained at 100 °C was used as a heat source, and the rate of heat flow to a copper plate placed over it was measured. Ionic wind was induced by corona discharge with a needle placed on the heater. The experiment shows that the ratio of heat transfer coefficients obtained with corona discharge to that without the discharge was in the range of 3–4, with an energy efficiency of around 10. The heat flux at this condition was approximately 400 W/m². The numerical simulations indicate that the heat transfer is enhanced by ionic winds, and the results were found to corroborate well with the experimental ones.

We have developed a single layer thin film heat flux sensor using MEMS technology to quantitatively evaluate a cooling loss inside the engine. The sensor succeeded in capturing high-speed heat flux fluctuations, however the direct current component of the heat flux wasn’t measured since thermal information on the backside of the sensor substrate was unknown. In this study, we developed a double layer thin film resistance sensor for measuring the total heat flux including both DC and AC components. We report that how much thermal resistance should be given to the mathematical model according to the known heat flux by using impinging jet and a comparison among temperature measurement methods, an individual and a differential method.

A micro-machined thermal flow sensor, i.e., “Flow vector sensor (FVS)”, can measure air-flow velocity and direction. We numerically examine heat transfer phenomena for the FVS, to clarify its thermal characteristics. The heat transfer from the FVS to air-flow is found to affect the measurement accuracy, especially in high-speed winds.

In recent year, for the purpose of reducing carbon dioxide emissions through energy saving, new architectural materials are developed for ceilkling, wall, floor, window and door to improve insulation performance of houses. However it is difficult to estimate their influence on overall insulation of houses. In this paper, a polycarbonate window coated with nano hollow particles was picked up, and then a multiscale numerical simulation was conducted for a model room. The homogenized material properties of coated layer were evaluated through asymptotic homogenization simulation, and quivalent properties of laminated window were obtained by the mixturing rule. The overall insulation performance of the model room was discussed from finite element simulation of nonsteady thermal conduction problem.

Wind and solar power generation is gathering attention as the solutions of global warming, but not being introduced in large scale because of its unstable output. This paper analyzes the mitigating power fluctuation of these variable renewable energy toward reducing CO₂ emission in Hokkaido. The analysis takes into account wind and solar data in one-hour interval for a year, and calculates annual total cost by linear programming. Conventional analysis specified renewable energy share of annual total electric power demand, and new analysis method defines CO₂ reduction rate. The result shows that it is possible to reduce 60% CO₂ Emission from actual value in 2013 without so large increase in total cost. However, surplus power and total cost increase due to power fluctuation of renewable energy in case of reducing more than 70%. There is difference between conventional and new analysis methods, and it indicates needing extra cost on the assumption of expanding renewable energy share compared with optimal composition with same CO₂ reduction rate. Considering the situation with charging electric vehicles from power grid, we found that the electric vehicles are effective for usage of surplus power.

This paper discusses the future power and heat supply systems at the time of disaster in Hokkaido. A power supply model for the four separated regions of Hokkaido is developed, and the capacities of power generation equipment to meet the power demand with the minimum cost are analyzed. The power supply costs with and without power transmission between the regions are compared in two scenarios, with and without fluctuation countermeasure technology. In both scenarios, the cost tends to increase from the renewable energy share of 50%. Moreover, as the share increases, the cost difference greatly increases when comparing both scenarios and at the same time, the cost difference becomes more prominent with and without the transmission. In addition, the output fluctuations with a renewable energy share of 80% in the storage battery introduction scenario are compared, and it is shown that charging/discharging of the storage battery has a great influence on output levelling in case with no transmission. Further, this research plans to develop the optimal heat supply system which can supply the minimum heat to public facilities in a region, especially in winter.

The dynamic characteristics of a self-circulating thermosyphon (SCTS) for the purpose of utilizing solar thermal energy were investigated. This thermosyphon is operated by the steam generated when the working fluid is heated, so it does not have an external driving source. In this study, the dynamic characteristics of a SCTS during a cold start are investigated experimentally and by numerical simulation. As a result, it was found that a large flow fluctuation appeared in the initial stage of startup and its frequency increased as the temperature of the working fluid increased. These characteristics are considered to be affected by the boiling state in the heating section.

Generally, it is said that the ground source heat pump (GSHP) can operate with less power consumption than the air heat pump. With a direct expansion method GSHP, it is possible to terminate the evaporation/condensation process of the refrigerant within the geothermal heat exchanger within a depth of 30 m by a proper design, but we need think about the heat collection and release characteristics during high load continuous operation. Therefore, the behavior of water in the bore hole that insert the heat exchanger was obtained by three-dimensional numerical analysis, and the heat collection characteristics in the bore hole during heating and hot water supply operation were investigated.

A novel flow meter using a circumferential heater, which measures the steam velocity in pipes, has been developed for performance diagnosis and energy solution in facilities such as factories and power plants. Since this flow meter can be installed from the outside of the steam tubing, it is not necessary to stop the operation of the facilities. In this study, CFD simulation that reproduces the operation of the steam flow meter was performed and a simple method for the prediction of steam velocity with the flow meter was discussed. The velocity predicted with the method showed a good agreement with the velocity measured with coriolis flowmeter.

Renewable energy cannot be widely promoted without political supports. This study examines the conditions under which three types of energy policies, carbon tax, subsidy, and price regulation are accepted in competitive markets, and the relationship between the acceptability of these policies and the progress of energy transition from fossil fuels to renewables. A gaming experiment that regards human gameplay as a kind of social simulation is adopted as research method. The multiplayer game used in this study represents a dilemma between the long-term profits by investments in renewable energy and the short-term profits by price competition. The perceptions and behaviors of players and the time-series changes in the state of market are obtained from the gameplay. The results of the experiments suggest that the acceptability of carbon tax increases as the fossil fuel price rises. Further, the voluntary investment in renewable energy is suggested to be hindered by the expectations for subsidies to renewables.

It is known that small lift-type vertical axis wind turbines have high solidity and their output characteristics are different from those of large wind turbines, BEM model, and double multiple streamtube model. The interference of the blade wake is assumed to be the cause of these difference. Previous studies have investigated the effect of number of blades and turbine diameter. The results obtained showed that the increase in solitude causes blade-wake interference at lower TSR and it impedes an operation at high TSR, which is an advantage of the lift type turbine. However, it has not been clarified that this blade-wake interference does not occur in low-solidity turbine. The purpose of this study is to investigate the effect of the cord length of the blade on the wake of the low-solidity wind turbine and to clarify the characteristics of the wake flow. It was found that the mean velocity profile in the wake of turbine using short chord blade is differ from that of the high-solidity wind turbines, and there is no interference of the blade wake. This feature depends on the solidity and interference of the blade wake occurs at σ>0.1.

Computational Fluid Dynamics (CFD) using the Dynamic Fluid/Body Interaction (DFBI) model had been carried out to investigate the wind direction dependency of a 2D-rotor pair. Although the experiments showed the tendency of greater influence of the deflection of the wake in the CO (co-rotating) condition than the IR (inverse-rotating) condition, the CFD analysis showed the opposite tendency in the power distribution. There was no clear difference between the CO and IR conditions in regards to the power per unit area of the rotor pair.

Studies on vertical axis wind turbine have been conducted mainly on output performance during power generation operation. On the other hand, there are few studies on the load acting on the wind turbine. Especially, the aerodynamic load acting on vertical axis wind turbine in parking condition is dominant in the design due to the extreme wind speed such as typhoon, and the clarification of the load characteristic is important for the safety design of the wind turbine. In this study, we clarified the aerodynamic load acting on the blade of straight-blade vertical axis wind turbine in parking condition with CFD analysis. At that time, we set up analysis model as in the experiment conducted in the previous research and performed CFD analysis. As a result, the analysis results generally capture the tendency of the experimental value of the change of the resultant force coefficient acting on the blade, and even if the wind speed changes, the change in the maximum value of the resultant force coefficient acting on the blade was small.

The vertical axis wind turbine has a characteristic that the angle of attack of the blade fluctuates greatly during one revolution, and the separation and reattachment of the blade surface flow are repeated. Due to its characteristics, the wake of the wind turbine has a complicated flow field compared to that of the horizontal axis wind turbine. In this study, we conducted a field experiment to clarify the wake behavior of a vertical axis wind turbine under unsteady natural wind conditions. In the field experiment, the velocity field was measured using multiple ultra-sonic anemometers installed downstream of the test wind turbine, and the flow field inside wake of wind turbine and the wake influence range of the wind turbine were investigated. In addition, the discrete data obtained in the field experiment was fitted with a Gaussian function and wake models were created to quantitatively evaluate the wake influence range of the wind turbine. As a result, the tendency of the wake behaviour of the vertical axis wind turbine in natural wind was able to be grasped. Furthermore, the wake influence range was estimated by approximating the change of each parameter value of the wake models by linear functions.

The impact of wind condition and sea state on performances of the model predictive control previewing wave height as well as inflow wind speed for a floating offshore wind turbine-generator system is analyzed using an aero-elastic-hydro-control coupled simulation. The focused wind condition and sea state are different from those used for the identification of the internal model to predict the control behavior in the prediction horizon, The simulation results show that the damage equivalent loads at the tower base and low-speed shaft as well as the variations in the rotor speed, generator power, and platform pitch are reduced by using the developed model predictive control in comparison with the conventional gain-scheduled feedback control of the generator speed and the model predictive control previewing only the wind speed. This reduction effect is also observed under the wind and wave conditions different from the identification data for the internal model.

There are many energy sources available in the environment but still not well utilized, such as the vibration energy. Therefore, we fabricated and studied a vibration power generator that uses vibrations generated by human walking. The fabricated vibration generator has an inverted pendulum in the center and piezoelectric elements around it. The inverted pendulum operates in the longitudinal and lateral directions. The collision between a weight attached to the tip of an inverted pendulum and piezoelectric elements generate electricity. In this study, we evaluate the power generation characteristics of the fabricated vibrating power generator by means of vibration experiments with different fixed angles. The results show that power is generated uniformly regardless of the fixation angles of the generator.

In recent years, power supply equipment which is resistant to the disaster is required due to because the large-scale blackout by natural disaster. On the other hand, there are problems such as an increase in elderly and a shortage of workers in the agricultural field, then the development of electrification and automation of agricultural machinery is underway as a measure to reduce the heavy burden on farmers. but the installation of the power supply equipment is required due to the essential to the continuous operation and charging time. In this study, we report the result of the characteristic of the generating power by the extra energy of the pipeline for agriculture, targeting nano hydraulic power (less than 10 kW) which are many undeveloped areas.

Preservation of Biomass Carbon is the most essential way to decrease CO₂ emission to zero, because there are many industries like Iron and Cement product cannot decrease CO₂ emission to zero. To realize Zero-Carbon with keeping economic development, Preservation of Biomass Carbon and most reliable powerful Nuclear Energy and Renewable Energy which involve unstable energy like solar cell and Fossil Energy must be used efficiently, really, mutually, adaptably. One Example, the CO₂emission of Jet-plains can be replaced to Preservation of Biomass Carbon equal to it.

Preservation of Biomass Carbon has so high value for Environment Protection, and is bought out by Government expenses, not by tax income. I estimate roughly that Preservation of Biomass Carbon 120Mton-C.yr^-1, Nuclear-Power reinforcement of 700TWh.yr^-1 and Renewal- Power reinforcement of 100 TWh.yr^-1 will be able to realize Zero-Carbon in Japan 2060.

I expect Zero-Carbon-World in 21Century-end will need about 4 Gton-C.yr^-1 of preservation of Biomass Carbon. This big demand for Suppressing GW will bring many new businesses that link Preservation of Biomass Carbon, Nuclear Energy, and Renewal Energy. Now! The Government daring policy is necessary to start up many new businesses.

BDF (bio diesel fuel) is a vegetable oil-based diesel fuel which contains more oxygen than gas oil. The purpose of research so far was to grasp the effects of the feature of BDF. To this end, performance testing was performed in small diesel engines using gas oil and BDF. The testing confirmed no significant effect on NOX concentration with the use of BDF as compared to the use of gas oil. Elsewhere, it is considered that the oxygen contained in BDF promotes combustion, as PM (particulate matter) emission increases are suppressed in conditions where the oxygen concentration decreases. However, there is very little oxygen contained in BDF compared to the oxygen contained in the engine intake air. Therefore, the effect of the oxygen contained in BDF on the diesel engine exhaust gas components was examined. It was thus found that the BDF oxygen content affects the reduction of unburned fuel, which is particularly related to PM generation, due to changes in HC concentration, CO2 concentration in exhaust gas, and exhaust gas temperature.

To achieve sustainable development goals, fossil fuel-independent power generation systems need to be established. In this study, we focused on the circulating flow generated by vibrating a flexible pipe containing liquid as an energy recovery device that converts vibration into flow, toward the development of a power generator using tidal current. In this report, we described its usefulness and power generation potential. It was suggested that the establishment of this system could take a step toward a low-carbon society and increase the possibility of achieving sustainable development goals.