Three-dimensional flow behavior of tip vortex in a half-ducted propeller fan has been investigated by a detached eddy simulation and vortex identification technique based on critical point theory. The tip vortex behavior is different between the opened region and the ducted region. In the opened region, the tip vortex core grows gradually as tip vortex convects nearly along main stream. In ducted region, tip vortex turns to the nearly tangential direction under the influence of the shroud surface and the concentration of vorticity around the tip vortex core diffuses gradually. Also, circulations of the blade and tip vortex were estimated. The reduction of blade circulation near the blade tip is comparable with the tip vortex circulation in the downstream of the rotor.

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To improve the aerodynamic performance of half-ducted propeller fans, it is important to reduce the separation zone, because it leads to energy loss. There is often a big separation zone downstream of the rotor blade root. A rotor blade, with tangential lean angle, has a blade force effect in the radial direction. It is found that the blade force in the inward radial direction is effective to reduce the separation zone and improve the aerodynamic performance of half-ducted propeller fans.

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Internal flow of a cryogenic rocket turbopump is rather complicated compared to ordinary pumps. In order to design stable axial thrust balancing system, dynamic analyses of the internal flow system is essential. In the present study, analysis program to analyze dynamic characteristics of leakage flow through the axial thrust balancing system was developed. In the program, structure of the balance piston type axial thrust balancing system and the internal flow passages are combined. Pressure perturbation was imposed on the inlet of the balancing system and the dynamic response of the axial thrust balancing system was evaluated. Calculated results showed that the system has resonant frequencies which depend on the fluids and the other parameters of the system.

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In the rocket turbopump, the balancing system with the balance piston is often applied to reduce the axial thrust. The leakage flow through the balance piston is affected by the configuration of the balance piston and the balancing point in the axial direction. In designing the internal flow system, the balancing point and flow rate have been estimated by the static analysis code of the internal flow. On the other hand, the analysis code for dynamic response of the internal flow through the balance piston was developed. In this study, optimal calculation considering the dynamic characteristics of the internal flow system was carried out by using the dynamic analysis code. As the results, the balancing point in the steady state significantly affects the leakage flow rate and the axial vibration.

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In a turbopump inducer of liquid propellant rocket engine, cavitation is affected by unsteady acceleration in an actual launch sequence. Because cavitation instabilities, such as rotating cavitation and cavitation surge, are suppressed in the flight, it is hard to obtain a data about influence of acceleration on cavitation instabilities. Therefore in this study, through numerical simulation of a three-blade cascade, influence of acceleration on cavitation instabilities in cascade is analyzed firstly for fundamental research. Several cases of acceleration are imposed to an axial direction of the cascade which includes both upstream and downstream direction. From numerical results, it is shown that cavity volume is suppressed and cavitation capability increases by the influence of acceleration to axial-downstream direction of cascade. Then, occurrence regions of each cavitation instabilities wholly move to low cavitation number region by small degree according to increase of acceleration. Also, in an acceleration field to downstream direction, sub-synchronous rotating cavitation and rotating-stall cavitation are not observed. On the other hand, rotating stall cavitation occurs in comparatively higher cavitation number region in an acceleration field to upstream. Then, acceleration to downstream direction is safe side against cavitation instabilities and that to upstream be the opposite.

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Aspect and temperature depression of cavity occurred on a NACA16-012 hydrofoil were experimentally investigated with liquid nitrogen in order to comprehend the degree of thermodynamic effects on cavitation. It was found that cavity was made of uniform cluster of tiny bubbles and the degree of temperature depression increased as the inlet cavitation number decreased. Moreover, the mean thickness of liquid layer where its temperature decreased due to thermodynamic effect did not so vary whenever Reynolds number increased. This can be considered because large amount of tiny bubbles suppressed flow disturbance and also turbulent heat transfer in cavity on a hydrofoil.

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In recent years the fan heater used for industry and residence has become smaller, lighter and more silent as the result of improvement. However there are problems that the fan heater size is very large, and the noise is very high due to air pressure loss of heat exchanger. Therefore we have been developing the centrifugal type fan with the function as heat exchanger. The features of this new type fan heater are that the fan heater size is very small and silent because the fan and the heat exchanger are in one body. This paper described the effects of the flow velocity distribution on different scroll tongue by numerical simulation with Front Flow/blue. In RO scroll, inner flows that after passing scroll tongue effects pressure distribution. Negative pressure area distribute more broadly near the scroll tongue. This negative pressure draws inner flow on pressure side surface. In contrast, inner flow between fan blades with R7.5 scroll is stable steady flow so that negative pressure area is reduced.

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This paper investigates the effect of the casing movement relative to the blades on the tip leakage flow in axial flow compressors by using experiments and computational fluid dynamics. Traverse measurements in the pitch-wise and span-wise directions are made using a five-hole Pitot tube at the inlet and exit planes of a compressor linear cascade comprising seven equally-pitched blades test facility. A moving belt, driven by a motor and a pulley system, runs linearly at constant speed under the horizontally suspended cascade to simulate the relative motion of the rotating blade and the casing. The experimental results, at 2% and 4% tip clearance to blade heights, indicate that the tip leakage loss decreases when the casing is in movement. These trends are similar to computational fluid dynamics results.

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Numerical investigation of an axial flow fan is carried out in order to clarify effects of an air separator. Steady state numerical simulations are conducted with ANSYS CFX with and without the air separator. The numerical result shows acceptable agreements with the experimental result for the total pressure performance curve and axial velocity distributions downstream of rotor impeller. With the air separator, the reverse flow is suppressed at the low flow rate where the stall occurs without the air separator. Additionally, the axial velocity distribution downstream of the rotor is also modified and consequently, the performance at low flow rate is improved.

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At near-stall condition in a low speed axial flow compressor rotor with large tip clearance distinctive disturbances are observed, which repeat appearance and disappearance irregularly and never develop to rotating stall cells. Compared to the small tip clearance case, the pressure fluctuation on the pressure side near the leading edge of the rotor blade and the turbulence intensity near the casing wall downstream of the rotor are high in the case of large tip clearance. Using Synchronous Field Measurement Technique (SFMT), by which the instantaneous casing wall pressure distributions are acquired, and Detached Eddy Simulation (DES), the flow mechanism of the distinctive disturbances has been investigated in the present study. The measurement and DES results show that the spiral-type vortex breakdown occurs in tip leakage vortices and it makes the strong unsteadiness in the flow field across the fore part of blade passage near the casing wall.

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Transonic centrifugal compressor impellers for automotive turbochargers operate from near surge limit to choke limit. In order to improve the performance, it is indispensable to understand complicated flow phenomena in impellers at off-design point. In this study, two types of transonic centrifugal compressor impellers with splitter blades, which are different in aerodynamic characteristics, have been investigated by DES(Detached Eddy Simulation). In comparison of total performance, the simulation results showed good agreement with the experimental ones. The simulation results revealed that the stall pattern was different between the two compressor impellers. In one of the two compressor impellers, vortex breakdown happens in the tip leakage vortex of full blade in all the passages, which expands the blockage near the tip and then suppresses the rotating stall. In the other compressor impeller, the rotating stall cell is formed at stall inception without the vortex breakdown in the tip leakage vortex of full blade, and grows with decreased flow rate.

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In recent years, Environmental problems are becoming serious. For example, large amounts of CO_2 by thermal power generation cause global warming, and there is a strong demand for the spread of the power generating system by clean energy. Therefore we pay attention to micro hydro-power generation. Reverse running pump turbine would be used as a small hydro-turbine because of reliability and sales performance of pump. However, performance of the reverse running pump deteriorates by foreign substances and it occasionally falls into non-operating condition. These problems are important in working running pump turbine, and it is necessary to improve them. On the other hand, single-blade centrifugal pump has an outstanding characteristic to keep wide flow passage. Then, a single-blade reverse running pump turbine was adopted for a small hydro-turbine with excellent non-clogging characteristics. The relationships between turbine and pump characteristics of single-blade reverse running pump were investigated by and experiment and CFD in this research.

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Fluid machineries for fluid food have been used in wide variety of field i.e. transportation, the filling, and improvement of the quality of fluid food. As for the research on them, because the targeted fluid is different from air and water, the flow field is very complex and unclarification. Therefore, the design based on internal flow conditions is not so performed at present, and it chiefly pays attention to the transit performance and the product development is done. This research targets the food transportation pump. It aims at the improvement of the transit performance considering the quality retention of the food fluid. In this research, turbo-pump having small number of blade number was used to decrease shear loss and keep wide flow passage. Performances and internal flow conditions of turbo-pump using low viscous fluid were clarified by experimental and numerical analysis results. In addition, the design method based on the internal flow is considered.

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Rotordynamic forces acting on a conical shroud are calculated based on the simplest bulk-flow model. Semi-analytical solutions are presented under a few simplifying assumptions as follows, (1) wall shear stress is neglect, (2) no leakage flow, and (3) steady tangential velocity is forced vortex distribution. It has worth to elucidate the fundamental mechanism of rotordynamic forces acting on a conical shroud.

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Flow between rotating disk and stationary wall with different rotating speed and gap scale is analyzed numerically. The result with very fine grid with SST turbulent model agrees very well with experimental result, when the local rotating Reynolds number is high. The velocity distributions show some similarity law, and the thickness of boundary layer is different between rotational and radial boundary layers. The interference of boundary layers is also detected by the velocity distribution, and in the area of R>0.8, some linear relation exists on the interference conditions.

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Various fluid phenomena appear in AT(Automatic Transmission) depend on the parts and conditions. Acceleration by starting and braking a vehicle, affect the free-surface phenomena in oil pan of AT. Visualized apparatus for accelerated water vessel was established for analysis of the phenomena. EFD techniques, using high-speed camera, laser sheet visualization and wave-height sensor array, evaluate the precision criteria of CFD for free-surface phenomena. As a result, wave-height accuracy was within 10% and the time delay was within 40 msec.

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Lymph node metastasis (LNM) is the major prognostic factor for cancer survival. We have developed the pressuredriven metastasis of LNM mouse model. In this model, metastasis is induced by injection of tumor cells into the groin lymph node (gLN), followed by induction in the axillary lymph node (aLN). However, the mechanism of metastasis has not been fully elucidated. In this paper, we investigate the characteristics of the flow to the lymphatic vessel (LV) upon increased pressure in the gLN. Following administration of fluorescein isothiocyanate (FITC) to the gLN, FITC flow and pressure inside the LN were simultaneously monitored. We also succeeded in visualizing the FITC flow in the LV. These results show potential of developing an effective therapy of LNM by administration of drugs via the LV.

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The combination of ultrasound and nano-bubbles coated with lipid bilayers (i.e. hybrid nano-bubbles) induces transient membrane permeability, leading to direct delivery of exogenous molecules (such as plasmid, siRNA, panticancer drugs, proteins etc.) into cells with minimal invasiveness. This method is generally termed `sonoporation' in drug delivery systems parlance. When Kir6.2 genes have transfected into native smooth muscle layers of mouse aorta by use of sonoporation, RT-PCR analysis revealed the expression of Kir6.2 transcripts in vascular smooth muscle. When Kir6.2 genes, tagging with Myc-genes, were transfected into native smooth muscle layers using sonoporation, immunohistochemical studies have revealed that Kir6.2 and Myc proteins were co-expressed in vascular smooth muscle cells. The phenylephrine-induced contraction of mouse aorta was significantly reduced after the treatment of Kir6.2 gene-sonoporation, hyperpolaring the membrane potentials. These results suggest that Kir6.2 genes were functionally expressed in mouse vascular smooth muscles, causing a vascular relaxation due to the activity of Kir6.2.

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Coarse grained molecular dynamics simulations of a phospholipid bilayer under cyclic stretching are performed. The cyclic stretching is expressed by changing a position scaling factor sinusoidally so that the areal strain of the bilayer varies in the range from 0 to 1 at 1 MHz. It is found that the total potential energy of the bilayer system increase with stretching and drops when the areal strain exceeds 0.8, where a pore structure penetrating the bilayer forms. The range where the pore forms is consistent with the previous all-atom MD study of bilayer rupture. Once the pore structure forms, the pore structure is stable during contracting until the areal strain reaches 0.1, which leads to different pathways of the energy change during stretching and contracting.

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This paper describes analysis of stress wave propagation inside the cells by working shock waves to investigate effects of shock waves on cells for developing shock wave regeneration systems. In this investigation, effects of boundary conditions such as attached cell or suspended cell and rise time (shock wave frequency) on stress wave (von Mises stress wave). It was found that there are some variation of stress wave from averaged stress after incident wave applied the cells, and the amplitude of the stress variation depends on rise time. To certificate the computational results, the effects of shock waves on the endothelial cells in vitro the cells by plane shock waves using shock tube apparatus are examined., and it was found that the experimental results agree with CFD results.

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This paper describes the fundamental investigations for developing new technology using pressure waves and bubbles such as drug delivery systems (DDS). The microcapsules made of lipid including gas bubble were made by controlling ultrasound and gas flow rate. We examined the effect of ultrasound intensity and gas flow on particle diameter and diameter ratio of gas-liquid. Also, effects of working pressure amplitude and mechanical index on disintegration efficiency of capsule were examined. As a result, there are possibilities to disintegrate microcapsules efficiently by controlling pressure amplitude and frequency.

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Sonazoid microbubbles have been destroyed by the irradiation of a 1 MHz ultrasound (US). Both burst waves and continuous waves of US were radiated by means of a concave ultrasound probe with the arithmetic focal length of 80 mm. A suspension of Sonazoid ultrasound contrast agent with the volumetric concentration of C. was poured into a cuvette which was positioned with its bottom in contact with the free surface and exposed to US with the duration of T. After the interaction between a suspension and an ultrasound, Sonazoid microbubbles were quickly destroyed. The survival number of Sonazoid microbubbles has been examined by changing the exposure time T・, the concentration of a suspension Cs and the duty ratio D. Sonazoid destruction yields several pieces of debris together with gas flowing out which act as nuclei of bubble growth. Snapshots of bubbles were taken by using a Xe flash with the pulse duration of 2 ps as a light source.

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This paper deals with a numerical simulation based on the multigrid ghost fluid method for mass transfer associated with bubble collapse induced by a shock wave to clarify the relationship between the liquid jet and the delivery of drugs around a bubble. The results show that matters concentrate in the liquid jet head before jet impact. After then, they are taken in the vortex flow around the toroidal bubble and delivered downstream due to convection. Also, in terms of a concentration centroid, it is shown that the lower Peclet number is, i.e., the more prominent diffusion is, the more distance the concentration centroid translates in the radial direction, and the less distance in the axial direction.

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The panel architecture of the soccer balls used in the World Cup has changed in every four years' convention. It is understood that the change in the panel structure in the soccer ball exerts a big influence on the aerodynamic characteristics. It is well known that the non-rotating shot by "Team Geist" appeared in 2006 becomes a oscillating ball in the long or middle distance shot. Especially, the unpredicted shot trajectory was a problem for "JABULANI," the 2010 World Cup official ball. "Speed Cell" was appeared to fix the deficit of "JABULANI" as an official ball of FIFAWomen's World Cup Germany 2011. Both of the panel shapes looks the same but the aerodynamic characteristics of "Speed Cell" is different from "JABULANI."

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Concerning most of track-and-field athletics such as the marathon, it is important to elucidate the flow around track runners, and to evaluate their air resistances. In wind-tunnel experiments which are the most effective approach to such a study, the moving-belt system is indispensable for precise aerodynamic measurements considering the ground effect. Recently, the authors have developed the device, and show its basic performance such as the distributions of time-mean velocity and turbulent intensity above the moving-belt system using a hot-wire anemometer. In the present study, the authors reveal the air resistance of a runner in various tandem-running formations.

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Badminton is a well-known sport that young and old can enjoy. The reason why it can enjoy everyone is in a strong deceleration of the shuttlecock, however, its aerodynamic characteristics have not been elucidated well. In the present work, using a low speed wind tunnel, aerodynamic force and moment acting on the shuttlecock is measured in the angle of attack rage from -10° to +10°. Effect of the flow passing through the gap (Overlapped part of the feather) on the lift characteristics is demonstrated. Due to these effects, non-liner lift characteristics (N shaped change) depending on roll angles are observed around the angle of attack zero.

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In the previous study, the swimmer mannequin, which reproduces the 3D body shape of an athlete swimmer with high fidelity and can perform three degrees-of-freedom motion, was developed, and the fluid force acting on the swimmer mannequin was measured. In this study, the unsteady fluid force acting on the swimmer mannequin was modeled. The formulation of the swimming human simulation model SWUM, which the authors have already developed, was used for the fluid force model. Three fluid force coefficients in the model were determined using the optimizing calculation so that the discrepancy between the simulated fluid force and experimental one became minimum. Further, the unified coefficients were determined by taking the averages of the values for all the trials. Using the unified determined fluid force coefficients, the comparisons between the simulated fluid forces and the experimental ones were carried out. It was found that the simulation could reproduce the experimental characteristics with respect to the time fluctuation.

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While the old yacht used only the drag of the wind, the recent yacht uses the lift force generated by both the sail (wing in the air) and the keel-and-bulb (wing in the water).When the ship heels, the keel-and-bulb make the restoration moment and stabilize the ship. In this study, we investigate the properties of the keel-and-bulb which is used in the actual ship. Using the wind tunnel, the flow around the keel-and-bulb is visualized by smoke. The velocity field and the drag are analyzed by hot-wire velocimetry.

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A droplet is kept on a surface of a liquid pool for a certain time without merging separated by a thin air film if the temperatures of the droplet and the pool are sufficiently different. The surfaces of the droplet and the pool are locally heated or cooled each other. The nonuniformity introduces convections on the surfaces, and they induce a flow in the ambient air. The flow sustains the pressure of the thin air film that prevents the coalescence. In this study, the temperature of a droplet kept on a pool and the flow velocity at a point in the droplet were simultaneously measured. A heated silicon oil droplet with a diameter of about 4 mm was dropped on a silicon oil pool at room temperature. The droplet was kept for a few seconds on the pool, and then it coalesced. Temperature change of the droplet was measured by a thermographic camera. Microparticles had been put in the droplet as tracers to estimate the flow velocity in tangential direction near the bottom of the droplet. The temperature of the droplet increased for less than a second just after it was dropped, and it gradually decreased to a value slightly higher than the value of pool temperature, and then the droplet merged. While the droplet was cooled, the flow velocity was decreasing.

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In the present paper, we performed the numerical simulations and the theoretical analyses of the micro/nanoscale gas flow in the parallel gas bearings with baffle. It was found that high and low gas pressures were generated in gas bearings with baffle and as an average, high lift force was exerted on the upper surface. Our DSMC results coincided with them obtained by using molecular gas film lubrication (MGL) equation. In our analyses, the Reynolds equation using slip condition with 1st order precision overestimated the lift force and the Reynolds equation using slip condition with 2nd order precision underestimated the lift force. Even in the case when the gas was leaked through the narrow gap between the baffle and the counter surface, rather strong lift force was obtained in the DSMC simulation. This result shows the potential of this gas bearing system for MEMS/NEMS.

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It was found experimentally that the friction between a partly polished diamond coating and a metal surface was drastically reduced to zero as relative speed increased to a few m/s. It seems that diamond coating took off the counter surface because sliding was noiseless in their experiment. In the previous work, we performed numerical simulations of micro-/nanoscale gas flow between the two sliding surfaces and successfully reproduced lift force large enough to suspend the slider used in the experiment. In the present study, we investigate the effect of gas properties on molecular gas-film lubrication.

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In this research the momentum transport phenomena in a nanoscale liquid bridge were simulated by Molecular Dynamics method and its nanoscale characteristics were analyzed. Water was assumed as the lubricant. Momentum flux was generated in a liquid bridge by Lees-Edwards Method. Using the velocity gradient of the liquid bridge and the momentum flux, viscosity coefficients of the liquid bridge were obtained. We analyzed the dependence of the width of the liquid bridge on the viscosity coefficient in detail.

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NS-DSMC hybrid methods are used for numerical analysis when flow fields continuously transit from high density to high vacuum. For example these flow fields appear on space planes, satellite thrusters, and jet orifices making semiconductors. However, the results of those methods didn't have high accuracy and computational efficiency, because it is difficult to connect continuum methods and particle methods. Therefore the LD-DSMC hybrid method based on the particle method is proposed by Burt et al. The results of this method have high accuracy and computational efficiency because it is easy to connect between the particle methods. In this study, in order to develop the LD-DSMC hybrid code, we need to understand more about numerical analysis around a 2D cylinder by using NS and DSMC method at first. Then we estimate Kn dependence of flow by comparing between NS and DSMC results. The results show that the present DSMC results fairly agree with the experimental results. Drag coefficient and friction drag contribution on the drag increase as Kn becomes large.

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In porous media with holes as small as a molecular mean free path, Knudsen number of gas flow in the narrow channel is in the order of unity. Therefore, the direct simulation Monte Carlo (DSMC) method is suitable to solve the transport phenomena in porous media. However, even if the inside structures of porous media are measured transparently by microscopy technique such as 3D transmission electron microscopy (3D TEM), geometries obtained will be discrete. Moreover, performing DSMC simulation for nanoscale gas flow in porous media is difficult because of its complicated structure. Therefore, we need to estimate and simplify the real shapes of complicated channels inside porous media. In this work, we propose two schemes for estimation and simplification of solid bodies in porous media. In the first scheme, we simplify them as aggregations of cubes. In the second scheme, we simplify them as aggregations of polyhedra. We put cubes or polyhedra based on the discrete information of solid bodies in porous media. We examine merits and demerits of these schemes by performing numerical simulations of example problems.

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Pressure-Sensitive Paint (PSP) is a pressure sensor based on the oxygen quenching of the luminescence of luminophore. In general, the luminescent intensity of PSP depends not only on pressure but also on temperature. Therefore, it is necessary to simultaneously measure the temperature with the pressure to improve the accuracy of PSP measurement. The compound sensor composed of pressure and temperature-sensitive luminophore was developed for simultaneous measurements of pressure and temperature. However, some of such compound sensors suffer the degradation of the sensitivity and other properties. In this paper, we show the possibility of a compound PSP/TSP sensor using PtTFPP and CdSe/ZnS.

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A shock-heated molecular beam source which can generate high energy beams in a range of 1-several eV is presented. Non-diaphragm type design of the shock tube enables our beam source to repeatedly generate pulsed beams. Since the rapid evacuation of residual gases requires the reduction of the tube volume, the tube diameter is only a few millimeters. Moreover, the shock formation distance is made as short as possible by a current-loop valve which opens completely within 200 gs. The prototype beam source demonstrated repetitive beam generation with the translational energy controlled by the initial pressure ratio although the energy was limited to below 1 eV. In order to improve the performance of the beam source, we investigated shock propagation in convergent tubes whose diameter is comparable to the thickness of boundary layer. The results suggest that the optimized geometry with an improved evacuation system enables generating molecular beams with the energy of more than 1 eV at the frequency of 0.5 Hz.

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We propose a new method for measurement of the evaporation coefficient using sound resonance experiment based on a theory of molecular gas dynamics. The evaporation coefficient is one of the parameters contained in the kinetic boundary condition. The evaporation coefficient of water is determined from the pressure amplitude of resonant sound wave in a cylindrical space bounded by a sound source and a vapor-liquid interface. By comparing the pressure amplitude with a linear theory based on molecular gas dynamics, we prove that the evaporation coefficient of water is about 1.0 around 300K.

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The resonant gas oscillation excited in a one-dimensional space between an oscillating plate and a planer surface of a thin liquid layer on a quiescent rigid-wall is considered. Vapor flows with evaporation or condensation at the vapor-liquid interface are theoretically studied on the basis of a polyatomic version of Gaussian-BGK Boltzmann equation with a kinetic boundary condition including an evaporation coefficient.

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Numerical simulations for Couette flows in a dense gas are conducted based on the Enskog equation. In order to solve the Enskog equation, we use the particle scheme method, which is an extension of the well known DSMC method that is used to solve the Boltzmann equation. The results agree well with the solution of the Boltzmann equation, as the ratio of molecular diameter to the mean free path of the molecules, a/ A, becomes smaller. A thin layer is formed near a solid wall surface as the ratio al A becomes larger. We also find that the slip velocity on the solid surface depends on the ratio al A.

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The Couette flow of a rarefied argon (Ar) gas between two parallel walls is considered to investigate the characteristics of the reflected gas molecule at a platinum (Pt) wall surface which physically adsorbs water (H20) molecules. The analysis is based on the molecular dynamics (MD) method for the interaction of gas molecules with the water adsorbed wall surface together with the direct simulation Monte-Carlo (DSMC) method for the motion of gas molecule. The accommodation coefficients of energy, tangential, and normal momentums are obtained. The accommodation coefficients for the water adsorbed surface depend on the adsorption rate a The tangential momentum accommodation coefficient a first increases rapidly from the value of the clean surface up to about C:60.2-0.3 and then becomes small. The accommodation coefficients of energy and normal momentum for the water adsorbed surface decrease with increasing the adsorption rate 9, and the variation of the normal momentum accommodation coefficients an with 0 is larger than the variation of the energy accommodation coefficients aE.

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Non-equilibrium molecular dynamics (NEMD) simulations have been carried out to obtain new evidence for the inverted temperature profile. The inverted temperature profile is confirmed in the vicinity of the condensing surface. From a view point of irreversible thermodynamics, the criteria for the inverted temperature profile are examined with the NEMD data and it is found that the inverted temperature profile occurs without contradiction to the second law of thermodynamics without contradiction to the second law. A new definition of the accommodation coefficient for the reflecting molecule is proposed based on the comparison of the energy transferred by the reflecting molecule between the equilibrium and non-equilibrium conditions. The accommodation coefficient decreases with increasing the mass flux in the vicinity of the liquid surface and this is the reason for the inverted temperature profile. Also, a direct simulation of Monte Carlo (DSMC) method has been performed by applying the molecular boundary condition developed in the non-equilibrium molecular dynamics simulation. It is concluded that the reflecting molecules play an important role at the non-equilibrium liquid surface.

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The flow around micro-systems is so-called the high-Knudsen number flow. The flow field cannot be treated as a continuum and the thermal conduction should not be treated by ordinary Fourier's law. In high-Knudsen number flows, the gas-surface interaction becomes important and the energy accommodation coefficient is often employed to analyze heat transport phenomena. The energy accommodation coefficient varies depending on combination of surface materials and gas species. Thus, it is important to use the appropriate energy accommodation coefficient for each pair of surface and gas for accurate thermal management. In this report, we obtained the energy accommodation coefficients for argon in contact with platinum surface in accordance with the Low-Pressure method, using the theoretical heat flux equation expanded to transition regime. The experimental result was compared with previous result in literature, which reported a relation between the energy accommodation coefficient and the surface temperature, and they are in good agreement.

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In this paper, we have applied a most reliable ab-initio potential function for oxygen, which is one of liquid rocket propellants, for an aim of the estimation of the thermophysical properties. This intermolecular potential was constructed based on Molecular Orbital (MO) calculations by Bartolomei et al. (J. Chem. Phys., 2008), and the function was represented with a spherical harmonic expansion. We have calculated a Pressure-Volume-Temperature relationship and excess specific heat of oxygen using Monte Carlo (MC) calculations with this potential function, and its applicability has been examined.

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Combustion conditions in liquid rocket engines using oxygen-hydrogen propellant change in the wide region of temperatures and pressures. This combustion is greatly affected by the complex flow-field of oxygen and hydrogen near the injections in the combustion chamber. CFD is often used to understand the flow-field, but, equation of state that required for CFD has many unclear parts. Therefore, in this study, the accuracy of cubic type of equation of state focus on specific heat at constant volume and pressure against oxygen hydrogen mixture system was evaluated by using the molecular dynamics with ab initio potential by Koshi et al. As a result, Soave-Redlich-Kwong (SRK) equation of state with a conventional classical mixing rule showed good agreements with our calculation results for pressure-volume-temperature relationship, at least in the present conditions for oxygen-hydrogen mixture gases.

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The influences of the structural geometry at the nanometer scale on the thermal resistance at a liquid molecule-solid interface, as well as the interfacial local non-equilibrium behaviors of liquid molecules, were investigated directly by the non-equilibrium classical molecular dynamics simulations. A liquid molecular region confined between the solid walls, of which the interparticle potential was Lennard-Jones model or SPC/E model, was employed as a calculation system. The interfacial thermal resistance was dependent on the surface geometry at the nanometer scale and the interaction parameters between the solid atoms and the liquid molecules. The interfacial thermal resistance at the liquid-solid interface related to the interfacial local non-equilibrium behaviors of the liquid molecules regardless of liquid molecular degrees of freedom. The energy transport mechanism at the liquid-solid interface was changeable depending on the surface geometry at the nanometer scale under the present calculation conditions and it might relate to the variations of the interfacial thermal resistance and the local non-equilibrium behaviors of the liquid molecules at the liquid-solid interface.

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We conducted an analysis of thermodynamic property of cryogenic hydrogen using classical molecular dynamics. Especially, we investigated the effect of intermolecular potential model on thermodynamic and transport properties of cryogenic hydrogen. We applied three empirical potential models and one ab initio potential which was derived by Molecular Orbital (MO) calculation. We performed NVE constant Molecular Dynamics (MD) calculation to obtain Equation Of State (EOS). Moreover, we investigated transport coefficients (viscosity coefficient, diffusion coefficient and thermal conductivity) using Green-Kubo method. Simulation results were compared with NIST data using the principle of corresponding state. As a result, it was confirmed that every potential showed the same tendency and cannot reproduce NIST data at the high density region.

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The dynamic contact angle and the behavior of the contact line of water on platinum surface were investigated by using molecular dynamics (MD). The simulations were performed for a system in which water was sheared between two parallel platinum plates moving in the opposite direction with each other. The 2D-particle-mesh-Ewald method for long range force correction was used in the simulation. The contact angle defined with the water-vapor interface position in the 2nd and 3rd nearest layers along the wall was measured for the moving velocities of the wall. It was shown that the receding contact was decreased as the wall velocity was increased. The advancing contact angle was increased with the wall velocity. While the receding contact line (interface in the first nearest layer) did not move for the wall, velocity difference was observed between the advancing contact line and the wall. The fluid velocity near the receding contact line in the first layer was equal with the wall velocity up to the contact line, which indicates that the water molecules in the first layer were locked to the wall. On the other hand, the fluid velocity near the advancing contact line was slowed down in the vicinity of the contact line.

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A non-thermal very-high-frequency plasma is used to synthesize luminescent silicon nanocrystals from silicon tetrachloride. The average nanocrystal diameter can be varied between 3 to 12 nm with narrow size distributions and the size can be adjusted independently of the relative hydrogen and argon concentrations in the plasma. The photoluminescence of oxidized nanocrystals can also be varied from 650 nm to 900 nm. The surface of the nanocrystals is terminated with hydrogen and chlorine. The nanocrystals oxidize at significantly faster rates than purely hydrogen terminated nanocrystals, but slower than fluorine terminated nanocrystals indicating the electronegativity of surface terminating atoms strongly influence the oxidation process.

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Conventional cancer therapy includes Surgery, Radiotherapy, Chemotherapy, Hormone therapy etc.. Improved methods to cure cancer is being studied. Great progress has been made in the field of nano materials given their great potential in biomedical applications. Due to their unique physicochemical properties of, Carbon Nanotube (CNT) have become a popular tool in cancer diagnosis and therapy. Over the last several years, CNTs have been explored in almost every single cancer treatment modality, including drug delivery, lymphatic targeted chemotherapy, thermal therapy, photodynamic therapy, and gene therapy. Carbon nanotube have an exceptional mechanical property which could be used in Cancer Therapy inside the human body. In this paper, we discuss about Multiphysics simulation and Analysis using COMSOL Multiphysics, regarding cancer therapy using Single Walled Carbon Nanotube (SWCNT) in destroying cancer cells with the help of Near Infrared (NIR) Irradiation. This simulation could help the research based cancer therapy using CNT more faster, cheaper way with accuracy. It is found that the results simulated in COMSOL4.1 is matching the research work, which is explained here.

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In this paper, we report vibration characteristics of a micro beam array for a novel acoustic sensor with wide-range frequency selectivity. Micro beams which have different dimensions in the length and the thickness were fabricated by single lithography using a gray-scale mask and a negative photoresist. The vibration characteristics in air were investigated by applying sound to the micro beams. The measurement result appeared that the vibration of micro beams is dominated by bending one and the amplitude increases at the resonant frequency of the first mode.

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