Dissipation Method Research Articles

Rapid degradation of the sulfonylurea herbicide–chlorimuron-ethyl by three novel strains of fungi

Chlorimuron-ethyl is a sulfonylurea herbicide with broad-spectrum weed control characteristics, low utilization rate, relatively high persistence in the soil. Chlorimuron-ethyl has been widely used world-over, and strategies for its removal have attracted increasing attention. Microbial degradation is considered the most acceptable dissipation method. We obtained the best biodegradation conditions using response surface methodology. Through the cleavage of the sulfonylurea bridge, we proposed a metabolic route for chlorimuron-ethyl degradation. Under these conditions (pH 6, 30 °C), Irpex lacteus could degrade 72.40% of the initially supplemented 40 mg L−1 chlorimuron-ethyl within 7 days. The half-life of chlorimuron-ethyl after inoculation was fairly short (4.696 days). The biodegradation rate of chlorimuron-ethyl by Irpex lacteus was 56.1%, which was higher than that of Phlebia sp. (50.8%) and Funalia trogii (25.4%). The pH value has an impact on the free state of the substrate molecule and the dissociation state of the enzyme molecule. The biodegradation rate was the highest (58.5%) at a pH value of 6. When the temperature was 30 °C, 56.3% of chlorimuron-ethyl was eliminated. As the temperature increased, the biodegradation rate of chlorimuron-ethyl by white-rot fungi decreased. Based on the results of LC–MS analysis, a metabolic route for chlorimuron-ethyl biodegradation was proposed. The fragment at m/z 161 (2-amino-4-chloro-6-methoxypyrimidine) originates from the cleavage of the C-N bond of the sulfonylurea bridge, while generating ethyl 2-sulfamoyl benzoate. The fragment at m/z 202 (2-sulfamoyl benzoic acid) corresponds to the ethyl group lost from ethyl 2-sulfamoyl benzoate. Due to the different secreted enzymes, there was a gap between the three strains in the degradation efficiency of chlorimuron-ethyl. The degradation rate of the herbicide by Phlebia sp. was the highest (61.7%), while by Irpex lacteus was the lowest (42.7%). Three white-rot fungi could degrade chlorimuron-ethyl in malt extract. LC–MS analysis indicated that the cleavage of sulfonylurea bridge through Irpex lacteus mediated the degradation of chlorimuron-ethyl. And, inoculation with white-rot fungi enhanced chlorimuron-ethyl degradation in aseptic soil samples. This is the principal report revealing that white-rot fungi can evacuate sulfonylurea herbicides, demonstrating that white-rot fungi will give novel ideas into the biodegradation of herbicides.

Smooth Controllability of the Navier–Stokes Equation with Navier Conditions: Application to Lagrangian Controllability

We deal with the 3D Navier–Stokes equation in a smooth simply connected bounded domain, with controls on a non-empty open part of the boundary and a Navier slip-with-friction boundary condition on the remaining, uncontrolled, part of the boundary. We extend the small-time global exact null controllability result in Coron et al. (J Eur Math Soc 22:1625–1673, 2020) from Leray weak solutions to the case of smooth solutions. Our strategy relies on a refinement of the method of well-prepared dissipation of the viscous boundary layers which appear near the uncontrolled part of the boundary, which allows to handle the multi-scale features in a finer topology. As a byproduct of our analysis we also obtain a small-time global approximate Lagrangian controllability result, extending to the case of the Navier–Stokes equations the recent results (Glass and Horsin in J Math Pures Appl (9) 93:61–90, 2010; Glass and Horsin in SIAM J Control Optim 50: 2726–2742, 2012; Horsin and Kavian in ESAIM Control Optim Calc Var 23:1179–1200, 2017) in the case of the Euler equations and the result (Glass and Horsin in ESAIM Control Optim Calc Var 22:1040–1053, 2016) in the case of the steady Stokes equations.

Performance Evaluation of U-Tube Pulsating Heat Pipe with Water-Based Nanofluids

The safety and efficiency of electronic equipment are becoming increasingly critical as modern technologies progress significantly. The size of electronic equipment is shrinking as it becomes more integrated. Hence, the heat load per unit area increases, and the standard heat dissipation method may not fulfill their requirements. Therefore, Pulsating Heat Pipe plays an essential role in efficiently removing heat from congested surfaces to satisfy the requirement. To find optimized parameters for a PHP, various investigations are conducted in this work to help performance up-gradation of PHP. As the equipment gets smaller by size and more heat has to be removed from smaller surfaces, nanoparticles can significantly increase heat transfer performance. Furthermore, they can augment the heat transfer ability of fluids inside the PHP by providing capillary wicking, increased thermal effusivity, hydrodynamic instabilities, and structural disjoining pressure. In this work, various experiment is carried out with water-based Aluminum Oxide, Zinc Oxide, and Graphene Oxide Nanofluids. This work will help upgrade PHP's performance and thus help enhance heat transfer performance from smaller surfaces like Processor of Computers.

Justification for the culverts’ design with joint operation of a water cylinder with a side weir

The article is devoted to the actual topic of the substantiation of the culverts’ design with the joint operation of a water cylinder with a lateral flow outlet. In the article, the advantages and disadvantages of gravity and pressure flow are considered. Under catastrophic conditions, structures with a non-pressurized regime are safer since they have a high reserve of carrying capacity, and structures with a pressurized regime have a large carrying capacity. Today, there is a tendency to use energy dissipation methods using a water cylinder with a side outlet of the water flow in the bottom reach. It is necessary to use water flows when increasing the construction territory of hydraulic structures in mountainous and foothill sections of rivers. A design diagram of a water cylinder with a lateral water outlet when using water cylinder is proposed; the work shows a cylinder with a zero-bottom slope of a rectangular section. A roller with a rotation axis is considered in the article; the flow follows to the wall of the water cylinder along the length of the side walls, a water flow approaches with the expansion in the vertical plane of the side cutout; a flow is formed in the cylinder in the area of the tunnel joining to the cylinder, the outlet channel design and energy dissipation are also considered.

ANALISIS PERHITUNGAN PENDINGINAN TRAFO MENGGUNAKAN ISOLATOR CAIR MINYAK SAWIT

The transformer that functions to increase/decrease the voltage is heated due to the flow of electric current. The heat must be removed so as not to damage the winding. The heat dissipation method uses a liquid to propagate heat into the air. Currently, mineral oil is generally used, but to improve the environment and be more sustainable, it can be replaced with palm oil (CPO). The heat transfer palm oil of the transformer can be calculated. The heat propagates from the heat source through the paper to the CPO, then to the iron casing of the transformer and then to the free air. In order for CPO to cool properly, CPO needs to be cooled using forced air so that the heat transfer process is optimal. Based on the assumption of transformer parameters and CPO parameters such as heat capacity, conductivity, density, viscosity and others, it is obtained that the flow properties of CPO are laminar with Reynolds number of 293. Pradle number of 173.99 and Prandtl number of 30, then the convection coefficient CPO heat is 509.4 W/m2.oC. Based on the temperature in the coil of 80oC, the temperature calculation on the coil wrapping paper is 72oC, the temperature on the inside wall of the casing is 54.17oC and the temperature on the outer wall of the transformer or in the free air is 53.53oC so that it is still below the standard or acceptable. This shows that a 5,000 Watt heat source with a transformer casing length and width of 0.5 meters and a total radiator pipe length of 10 meters can reduce heat in the transformer. The comparison of the outside temperature in the air compared to the standard is 53.5oC/60oC or 89.2%.

ANALISIS PERHITUNGAN PENDINGINAN TRAFO MENGGUNAKAN ISOLATOR CAIR MINYAK SAWIT

The transformer that functions to increase/decrease the voltage is heated due to the flow of electric current.The heat must be removed so as not to damage the winding. The heat dissipation method uses a liquid topropagate heat into the air. Currently, mineral oil is generally used, but to improve the environment and bemore sustainable, it can be replaced with palm oil (CPO). The heat transfer palm oil of the transformer canbe calculated. The heat propagates from the heat source through the paper to the CPO, then to the ironcasing of the transformer and then to the free air. In order for CPO to cool properly, CPO needs to be cooledusing forced air so that the heat transfer process is optimal. Based on the assumption of transformerparameters and CPO parameters such as heat capacity, conductivity, density, viscosity and others, it isobtained that the flow properties of CPO are laminar with Reynolds number of 293. Pradle number of 173.99and Prandtl number of 30, then the convection coefficient CPO heat is 509.4 W/m2.oC. Based on thetemperature in the coil of 80oC, the temperature calculation on the coil wrapping paper is 72oC, thetemperature on the inside wall of the casing is 54.17oC and the temperature on the outer wall of thetransformer or in the free air is 53.53oC so that it is still below the standard or acceptable. This shows that a5,000 Watt heat source with a transformer casing length and width of 0.5 meters and a total radiator pipelength of 10 meters can reduce heat in the transforme

Dynamic response and failure mode of steel-concrete composite panels under low-velocity impact

There are two types of failure modes when a steel-concrete composite panel (SC panel) is subjected to low-velocity impact, local punching failure mode and overall flexure failure mode. Current studies have mainly focused on the former. To analyze the dynamic response process and mechanism of local punching failure, drop hammer impact test of seven SC panels, and static loading test of one SC panel have been completed. With increasing in impact energy, five types of damage patterns under the local punching failure mode appeared in turn. Comparing the residual deformation and the peak value of the membrane force, it could be concluded that reducing the spacing of tie bars improved the impact resistance of SC panels. The impact force-displacement curve of the drop hammer could be divided into five stages. Based on the dynamic response characterized curve and static loading test, a five-segment resistance function model for the entire process of impact response was proposed. The difference between the two failure modes of an SC panel under low-velocity impact reflected the different abilities to resist overall flexure failure and local punching failure. It also reflected the different method of energy dissipation. The criterion and formulas for distinguishing failure modes were proposed in this paper, and the calculation results were in good agreement with tests.

Estimation of Turbulent Triplet Covariances for Bora Flows

Bora is a strong or severe, relatively cold, gusty wind that usually blows from the northastern quadrant at the east coast of the Adriatic Sea. In this study bora’s turbulence triplet covariances were analysed, for the first time, for bora flows. The measurements used were obtained from the measuring tower on Pometeno brdo (“Swept-Away Hill”), in the hinterland of the city of Split, Croatia. From April 2010 until June 2011 three components of wind speed and sonic temperature were measured. The measurements were performed on three heights, 10, 22 and 40 m above the ground with the sampling frequency of 5 Hz. During the observed period, total of 60 bora episodes were isolated. We analyse the terms in prognostic equations for turbulence variances. In that respect, the viscous dissipation term was calculated using two approaches: (i) inertial dissipation method (εIDM) and (ii) direct approach from the prognostic equations for variances of turbulence (εEQ). We determine that the direct approach can successfully reproduce the shape of the curve, but the values are for several orders of magnitudes smaller compared to the real data. Further, linear relationship between εIDM and εEQ was obtained. Using the results for εEQ, viscous dissipation rate in longitudinal, transversal and vertical direction was determined. It is shown that viscous dissipation has the greatest impact on bora’s longitudinal direction. The focus is on the turbulence transport term, i.e., the triplet covariance term. For the first time, it is found that turbulence transport is very significant for the intensity of near−surface bora flows. Furthermore, turbulence transport can be both positive and negative, yet intensive. It is mostly negative at the upper levels and positive at the lower levels. Therefore, turbulence transport, in most cases, takes away turbulence variance from the upper levels and brings it down to the lower ones. This is one of the main findings of this study; it adds to the understanding of peculiarities of bora wind, and perhaps some other severe winds.

Generation of Shakedown Boundaries of Thin-Walled 90-Deg Scheduled Pipe Bends Determined Via Large and Small Displacement Finite Element Models

Abstract The present research investigates the effect of employing large displacement in finite element modeling on the generated shakedown (SD) boundaries of thin-walled 90-deg scheduled pipe bends. A recently developed methodology termed: shakedown limit—plastic work dissipation (SDLimit−PWD) method generates the SD boundaries via employing the large displacement in the finite element (FE) simulations. Additionally, a well-established direct noncyclic technique termed: shakedown direct noncyclic technique (SD_DNT) generates the SD boundaries via employing the small displacement formulation in the FE simulations. Comparing the SD boundaries generated via both methods illustrated a marked increase in the generated SD domains due to employing large displacement.

Asymptotic behavior of a solution to the drift-diffusion equation for a fast-diffusion case

We consider asymptotic behavior of a solution to the drift-diffusion equation for a fast-diffusion case. In the degenerate drift-diffusion equation, it is known that large time behavior of solutions converges to the Zel'dovich–Kompaneetz–Barenblatt (ZKB) function. For a fast-diffusion case, we show that the asymptotic profile for a solution is the generalized ZKB function such as the Talenti function. We use the entropy dissipation method combining the logarithmic Sobolev and the Shannon inequalities for the Rényi entropy that is known as an extension of the Boltzmann–Shannon entropy.

Assessing water requirement of orange trees using sap flow measurements in Narkhed-Pandhurna critical zone observatory (CZO) in central India


 We used thermal dissipation method for sap flux measurements in orange trees to assess its water requirement in Narkhed-Pandhurna region. Thermal Dissipation Probe (TDP) sensors were installed in 5-year old (young) and 15-year old (mature) orange trees to measure the diurnal sap flux variations in trees during November 21, 2019, to January 31, 2020 (71 days). The results show that the maximum daily water uptake by the 5-year old tree was 1.1 L observed on 39th day of measurement (December 29, 2019) and in the 15-year old tree it was 5.0 L, and it observed on 38th day (December 28, 2019) of measurement. The cumulative water uptake during the study period by the 5-year old tree was 49.0 L, and the 15-year old tree consumed 257.4 L of water. The results were compared with the recommended irrigational values of Indian Horticulture Board (IHB), Government of India (GoI) and Groundwater Survey and Development Agency (GSDA), Government of Maharashtra (GoMH) for orange orchards. The initial investigation shows that recommended guidelines for irrigation of orange trees are exorbitantly high and needs to be revised. The sap flow methods are more precise that can measure sap flow at a very short interval and can generate a time series of data. It can be used to revise the guidelines with the aim to conserve water and propose precision water irrigation for the study area in particular and different agro-climatic zones of the country in general.

Vortex Patterns Investigation and Enstrophy Analysis in a Small Scale S-CO2 Axial Turbine

Supercritical carbon dioxide (S-CO2) Brayton cycle system is a promising closed-loop energy conversion system frequently mentioned in the automotive and power generation field in recent years. To develop a suitable design methodology for S-CO2 turbines with better performance, an understanding of the vortex flow patterns and associated aerodynamic loss inside a S-CO2 turbine is essential. In this paper, a hundred-kilowatt level S-CO2 axial turbine is designed and investigated using a three-dimensional transient viscous flow simulation. The NIST Span and Wagner equation of state model that considers the real gas effects is utilized to estimate the thermodynamic properties of the supercritical fluid. The numerical methods are experimentally validated. The results indicates that the aspect ratio and tip-to-hub ratio are different in the S-CO2 turbine from that in the gas turbine, and the vortex flow patterns are influenced notably by these geometrical parameters. Both the vortex structure and moving tracks of passage vortices are changed as a result of large centrifugal force. An interaction between tip leakage vortex and hub passage vortex is observed in the impeller passage and its formation and development mechanism are revealed. To further explore the aerodynamic loss mechanism caused by vortex interaction, the energy loss in the impeller passage is analyzed with the enstrophy dissipation method, which can not only accurately calculate the energy loss but also estimate how the vortical motions occur. It is found that the enstrophy and energy loss can be effectively reduced by vortex interaction between tip leakage vortex and hub passage vortex. The results in this study would increase the knowledge of vortex flow patterns in S-CO2 turbine and the proposed enstrophy production method can be used intuitively to provide a reference for flow vortical motion study in turbines.

Active Thermal Regulation Systems for Footwear: Development of New Innovative Technologies

This work aims to develop safety shoes, with thermal regulation systems, namely innovative heating and cooling systems. Heating system was developed using printing techniques; and cooling system was developed using the integration of Peltier modules in the shoe structure. These materials are based on the Peltier effect, in which, when an electric current is applied, the heat moves from one face to the other, being subsequently removed using thermal dissipation methods. This effect allows an active cooling. Given the high technological challenge of integrating cooling systems into footwear, this paper will present only developments related to cooling system.

Characteristics of Energy Dissipation Rate Observed from the High-Frequency Sonic Anemometer at Boseong, South Korea

The characteristics of low-level turbulence at Boseong, located on the southern coast of South Korea, were investigated in terms of eddy dissipation rate (EDR) using 1-year (2018) of wind data obtained from the Boseong Meteorological Observatory (BMO), a World Meteorological Organization testbed. At BMO, a 307 m tall tower is installed on which four high-frequency (20 Hz) sonic anemometers are mounted at 60, 140, and 300 m above ground level (AGL). In addition, a sonic anemometer at 2.5 m AGL is located to the south of the tower. EDRs are estimated from the wind measurements based on three different EDR estimation methods. The first two methods use the inertial dissipation method derived from Kolmogorov turbulence theory, and the third uses a maximum likelihood estimation assuming a von Kármán spectral model. Reasonable agreement was obtained between the three methods with various fluctuations, including diurnal variations for all seasons, while the EDR calculated from the third method displayed slightly higher EDR values than the other two methods. The result of the analysis showed that the mean (standard deviations) of logarithms of EDR had larger values as height decreased (increased), and the means were higher in the unstable planetary boundary layer (PBL) than in the stable PBL for this heterogeneous location adjacent to the coastlines. The probability density functions (PDFs) of the EDRs showed that the distribution was well-represented by a lognormal distribution in both the stable and unstable PBL, although the PDFs at the lowest level (2.5 m) deviated from those at other levels due to surface effects. Seasonal variations in the PDFs showed that there was less difference in the shape of the PDFs depending on atmospheric stability in the wintertime. Finally, we calculate the 1-yr statistics of the observed EDR, which will be used for future LLT forecast systems in Korea.

Calculation method of time-variant additional damping ratio and bi-objective design of RC frame with BRBs

Additional damping ratio (ADR), which plays a significant role in damped structure design, is broadly utilized to evaluate damping effect of the dampers. In current method, the ratio of energy dissipated by the dampers in one complete cycle to maximum strain energy of the structural system is adopted as the value of ADR. In the computation of damper energy dissipation, the bilinear model is commonly used to characterize hysteresis behavior of displacement-dependent dampers such as BRB. However, the accuracy of the bilinear model is not precise enough. In the light of the Bouc-Wen model can accurately characterize hysteresis behavior of various dampers, the analytical solution of hysteresis energy is derived. The ADR calculation methods based on the strain energy and the energy dissipated by the inherent damping of the main structure are proposed, respectively. The bi-objective design method of the RC frame with BRBs is put forward. The damping effect of the dampers is included in the design objectives, which makes up the deficiency of single objectives with the story drift ratio. The design objectives are that the story drift ratio of the frame does not exceed the limit, and the damping ratio reaches the expected value. The layout and force of the dampers are taken as design variables. Based on the finite element method, a RC frame with BRBs is designed iteratively. The reasonable time period length of time-varying energy is determined. Meanwhile, the strain energy method and modal damping energy dissipation method are compared and analyzed. As a result, the calculation result of strain energy method is larger than that of modal damping energy dissipation method. The strain energy method is hazardous to structural safety, and the modal damping energy dissipation method is suggested. The bi-objective design method is effective, which can further improve the structural performance.

Role of trapped liquid in flow boiling inside micro-porous structures: pore-scale visualization and heat transfer enhancement

Flow boiling is an important heat dissipation method for cooling high heat flux surfaces in many industrial applications. The heat transfer can be further enhanced by using porous media surfaces due to their high specific surface areas. However, although flow boiling in channels is well understood, the phase-change behavior with the additional capillary effect induced by the porous structures is not well understood, and the design of the porous structures is difficult to avoid dryout and over-temperature accidents. A pore-scale lab-on-a-chip method was used here to investigate the flow boiling heat transfer characteristics inside micro-porous structures. The flow patterns, captured in the two-phase region with a uniform pore-throat size of 30 μm, showed that liquid was trapped in the pore-throat structures as both dispersed liquid bridges and liquid films. Moreover, the liquid film was shown to be moving on the wet solid surface by laser-induced fluorescence and particle tracking. A theoretical analysis showed that the capillary pressure difference between adjacent liquid bridges could drive the liquid film flows, which helped maintain the coolant supply in the two-phase region. The pore-throat parameters could be designed to enhance the capillary pressure difference with multiple throat sizes of 10 – 90 μm which would enhance the heat transfer 5% – 10% with a 5% – 23% pressure drop reduction. This research provides another method for improving the flow boiling heat transfer through the porous structure design besides changing the surface wettability.

Heat Dissipation System Based on Electromagnetic-Driven Rotational Flow of Liquid Metal Coolant

Abstract Liquid metal owns the highest thermal conductivity among all the currently available fluid materials. This property enables it to be a powerful coolant for the thermal management of large power device or high flux chip. In this paper, a high-efficiency heat dissipation system based on the electromagnetic-driven rotational flow of liquid metal was demonstrated. The velocity distribution of the liquid metal was theoretically analyzed and numerically simulated. The results showed that the velocity was distributed unevenly along longitudinal section and the maximum velocity appears near the anode. On the temperature distribution profile of the heat dissipation system, the temperature on the electric heater side was much higher than the other regions and the role of the rotated liquid metal was to homogenize the temperature of the system. To analyze the heat dissipation of the system performance, a second-order R-C network thermal resistance model of the experimental device was established with the parameters determined. The total thermal resistance of the dissipation system presented an increasing tendency with the increase of the heating power and gradually stabilized to about 4.42 °C/W. Besides, the relationship between the temperature of the electric heater and the heating power was experimentally determined. And it exhibits linear characteristic with the slope value of about 1.033 oC/W. With such corresponding relations, the heating power could be conveniently determined once the maximum control temperature was given. The heat dissipation method introduced in the paper provides a novel way for fabricating compact chip cooling system.

Relationship between pore water pressure and dissipated energy of fiber-reinforced sand

Under the loading of earthquake, sandy soil is prone to liquefaction and resulting in the superstructure damage. Therefore, the liquefaction identification of sandy soil is the primary task of liquefaction disaster prevention. Based on the energy dissipation method, the relationship between pore water pressure (u) and dissipated energy density (W) of fiber-reinforced sand (FRS) is established, and the effects of fiber length (FL), fiber content (FC), cyclic stress ratio (CSR), and relative density (Dr) on the accumulation of u are analyzed. The results showed that fiber addition can effectively slow down the liquefaction of FRS, and the curve of u and W can be divided into rapid growth stage, stable ascend stage and slow growth stage. When the u keep constant, the W increases with the increasing of FL and FC. Whereas, the u decreases with the increasing of FL and FC when the W keep constant. The u and W are less affect by CSR, and the dense sand of FRS is less prone to liquefaction than loose sand.

Short-time X-ray Irradiation as a Non-contact Charge Dissipation Solution for Insulators in HVDC GIS/GIL

The demand for DC gas-insulated switchgear/gas-insulated transmission line (GIS/GIL) becomes more and more urgent in recent years owing to the rapid development of high voltage direct current (HVDC) transmission systems. Insulators in DC GIS/GIL could easily accumulate a large number of charges on its surface during long-term operation, which might lead to overstressing of polymeric insulation or surface flashover. Therefore, it is of great significance to propose an effective method for dissipating extra surface charges. However, achieving charge dissipation without opening the tank is still a great challenge to SF6-insulated equipment for a long time. In this paper, a novel method, which is named X-ray based non-contact charge dissipation method (XNCDM) for insulators in SF6-insulated equipment, is proposed. The effects of X-ray irradiation on the charges dissipation and the influences of irradiation dose were experimentally investigated in SF6. The mechanisms underlying are discussed in detail. Results show that surface charges on the insulator can be almost completely dissipated after short-time X-ray irradiation with enough dose, owing to the significant enhancement of electric conduction along the insulator surface and charge neutralization by gas ions near the gas-solid interface. This paper provides a novel technique for realizing rapid surface charge dissipation on the insulator, which is of great significance for a variety of engineering applications of DC GIS/GIL.

The experimental study on the boiling bubble behaviors and heat transfer performance of the deionized water across various pin fins

Microchannel heat sink is widely utilized as one of the effective heat dissipation methods with lower heat transfer temperature difference. In this paper, visual experiment study has been conducted to focus on the inner relationship between heat transfer/flow properties in macroscopic aspect with bubble dynamic characteristics in microcosmic aspect. Results show that along with the increases of Re, the value of convective heat transfer coefficient(h) increases as well. Correspondingly, the pressure drops show a tendency as increasing, decreasing lately, then increasing again. The bubbles in the undergo the same four process: film boiling process, transition process from film to nucleate boiling zone, nucleate boiling process and single-phase convection process. And the variation of pressure drop is one-to-one correspondence with the four heat transfer process. Besides, the triangle pin fin holds the higher heat transfer coefficient, which may be explained from the quantities and the sequence of appearance of bubbles in nucleate heat transfer process. The migration diameter as well as coverage rate of bubbles appears the tendency as ascending firstly then down lately with the increase of Re, which fit the conclusion in macroscopic aspect in heat transfer/flow properties. It could be found that the migration size is mainly influenced by the flow rate as well as the density of bubbles. In this way, the position of bubble occurred is the key point effecting bubble growth time and growth radium. Three zones have been divided to summarize the dynamic behaviors of bubbles in different positions: The migration diameter of bubbles in Zone I in the biggest, with that in Zone II moderate and that in Zone II lowest. The tail of pin fin (Zone I) makes the bubbles more easily to merge the surrounding new nucleated small bubbles to a bigger size, with more residence time to leave the bubble growing bigger. The general growth size of bubbles in ellipse pin fin is smallest, around 0.08 mm and with growth cycle short as 0.616 s. Simultaneously, that of the triangle one is biggest, with the size as 0.099 mm and growth time as 2.112 s.