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Copyright of Light Industry Machinery is the property of Light Industry Machinery Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The theory of aircraft icing and its disaster mechanisms are crucial for preventing icing accidents and enhancing flight performance. The research progress on the flow field characteristics under different icing conditions and special wing configurations are systematically summarized in this paper. It is pointed out that, the actual three-dimensional ice shapes are complex, have multiple structural features, and coupling mechanisms with separated flow and turbulence structures should be further studied. The aerodynamic performance analysis of special wings under supercooled large droplet conditions is the significant future research direction. Turbulence field analysis focuses on identifying instability characteristics of the icing wing flow field and multi-scale structural interaction mechanisms. Exploring the ice-flow coupling mechanism is of reference value for developing multi-factor, multi-parameter, and multi-scale icing prediction and computational models.

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum Naturalium Universitatis Sunyatseni / Zhongshan Daxue Xuebao is the property of Sun-Yat-Sen University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Shanghai Jiao Tong University (1006-2467) is the property of Journal of Shanghai Jiao Tong University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Hydrocyclone is a common solid-liquid separation equipment, but due to its own structural limitations, the classification accuracy in the cyclone is not high. As the primary channel for multiphase flow entering the cyclone, the feed body has a significant impact on the classification performance of the cyclone. However, the problems of turbulent diffusion caused by high turbulent flow field in the feed body and low particle classification accuracy caused by collision and compression between particles urgently need to be solved. Therefore, a composite curve feed structure cyclone has been designed, which reduces the proportion of fine particles entering the bottom flow by regulating the internal flow field and particle motion in the feed body, thereby achieving the goal of improving classification accuracy. The numerical analysis method was used to explore the flow field characteristics and classification performance characteristics of five types of hydrocyclones with different feed-body structure: linear feed body, involute feed body, vortex feed body, linear guide feed body, and composite curve feed body. The superiority of the hydrocyclone with composite curve feed body was highlighted, and comprehensive exploration was conducted from the aspects of pressure field, velocity field, classification efficiency, and so on. Finally, experimental exploration was conducted on it. The results show that the composite curve feed body structure has better fine particle classification performance compared to other feed body structures, and the internal flow field is more stable. At the same time, the isobaric surface distribution shows regular changes, and the particle movement is more stable. The tangential velocity of the composite curve feed body is significantly higher than that of other feed body structures, and the particles obtain greater centrifugal driving force, making them easier to classify. The experimental results show that the separation efficiency of the compound curve feed body hydrocyclone is 46.32%, which is 7.32% higher than that of the conventional feed body hydrocyclone, and the content of -24 µm particles in the compound curve underflow is 15.07% lower than that of the conventional one. The content of -24 jum particles in the overflow is 3.39% higher than that in the conventional type, and the particle classification accuracy is greatly improved. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Posts & Telecommunications (Natural Science Edition) is the property of Chongqing University of Posts & Telecommunications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of South China University of Technology (Natural Science Edition) is the property of South China University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Acta Scientiarum Naturalium Universitatis Sunyatseni / Zhongshan Daxue Xuebao is the property of Sun-Yat-Sen University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Nuclear Safety is the property of Nuclear & Radiation Safety Center and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Atomic Energy Science & Technology is the property of Editorial Board of Atomic Energy Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The article researched simulation of the melted metal die forging process of temperature field, velocity field, shrinkage porosity and oxides of femoral stem of CoCrMo alloy and effects of casting temperature, mold temperature and forging speed on the filling and solidification with the help of the software ProCAST. The results indicated molten metal impact ran into the wall of the mold cavity and formed turbulent flow in the neck and head of the femoral stem, which posed risk of gas entrainment. Forging speed has obvious influence on oxides: the higher of forging speed, the lower of oxides contents. The molten alloy ran into the wall of the mold cavity and formed turbulent flow in the neck and head of the femoral stem whose top appeared oxides-rich area. CoCrMo alloy femoral stem whose casting was complete without shrinkage porosity have been gotten by injecting inert gas into the mold cavity before molten alloy pouring and setting the exhaust groove at the front of the femoral stem and exhaust plug at the highest position of the head of femoral stem. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Atmospheric turbulence is the main inducer of the unsteady characteristics in wind turbines. This study aims to explore the sensitivity to turbulence in the aerodynamic unsteady characteristics of the wind turbine airfoil using the large eddy simulation (LES). The turbulent inlet boundary was also generated using the Consistent Discretizing Random Flow Generation (CDRFG). The calculation domain and grid were then established, according to surveying and mapping of the outfield true blade. A series of wind tunnel experiments were carried out to verify the numerical simulation. Specifically, the airfoil was numerically calculated at 2°, 8°, and 14° angles of attack, where the turbulence intensity of the incoming flow was set as 9.6%, 6.5%, and 4.8%, respectively. Among them, the turbulence scale was of the same order of magnitude as the chord length of the airfoil. The results show that the turbulence increased the unsteady characteristics of the lift coefficient of the wind turbine airfoil. Specifically, the higher the turbulence intensity was, the stronger the unsteady characteristics were. The leading edge of the airfoil was much more sensitive to the incoming flow of turbulence, whereas, there was no influence of the turbulence on the middle and trailing edge of the airfoil. Once the turbulence intensities of incoming flow were 9.3%, 6.5%, and 4.8%, the standard deviations of the lift coefficient of airfoil were 6.36, 5.42, and 4.90 times that of the uniform incoming flow at 2° angle of attack, respectively, while the standard deviations of the lift coefficient of airfoil were 3.95, 3.33, and 3.02 times of uniform flow at 8° angle of attack, respectively, and the standard deviations of lift coefficient of airfoil were at 1.78, 1.63, and 1.40 times that of the uniform incoming flow at 14° angle of attack, respectively. It infers that there were much more significant fluctuation characteristics of the lift coefficient caused by the turbulence at the small angles of attack, compared with the large angles. When the angles of attack were 2°, 8°, and 14°, about 0.5, 0.3, and 0.1 times increases were found in the chord length for the standard deviations of the pressure on the suction surface from the leading-edge point to the position, compared with the uniform incoming flow, indicating the turbulence influence of pressure fluctuation on the suction surface in a larger area at a small angle of attack. The reason was also that the more significant characteristics were observed in the lift coefficient fluctuation caused by turbulence at the small angle of attack. Furthermore, the pressure fluctuations on the suction surface were larger than those on the pressure surface. As such, the suction surface greatly contributed to the fluctuations of the lift coefficient, indicating the relatively higher sensitivity to the incoming turbulent flow. A consistent trend was found in the power spectrum curve between the fluctuating pressure at the leading edge of the airfoil and the turbulent incoming velocity in the entire frequency domain region. Therefore, the turbulence of the incoming flow was dominated by the fluctuating characteristics of the pressure at the leading edge. Going back along the chord of the airfoil, the fluctuation pressure of the airfoil suction surface only responded to the incoming flow turbulence in the low-frequency region, while the pressure fluctuation at the high frequency depended on the own flow characteristics. Anyway, the aerodynamic sensitivity of wind airfoil to turbulence can be expected to reduce the power fluctuation for the better control strategy of the wind field. [ABSTRACT FROM AUTHOR]

Copyright of Ordnance Industry Automation is the property of Editorial Board for Ordnance Industry Automation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rolling Stock (1002-7602) is the property of Rolling Stock Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Irrigation & Drainage is the property of Journal of Irrigation & Drainage Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the heat transfer efficiency of circular heat exchange tube, the numerical simulation of circular heat exchange tube with rectangular vortex generator was carried out using SST k-ω turbulence model. The effects of the length-height ratio (L/H) and the attack angle (β) of the vortex generators on the flow and heat transfer characteristics were analyzed. The results show that four rectangular vortex generators generate two pairs of longitudinal vortices rotating in opposite directions, which enhance the mixing of hot and cold fluid, improve the field synergy in the circular tube and improve the heat transfer performance. The Nusselt (Nu) number, performance evaluation criterion (PEC) and friction fraction (f) of the heat exchanger tube increase with the increase of the length-height ratio of the vortex generator. With the increase of length height ratio of vortex generator, the increase range of comprehensive performance evaluation criterion (PEC) decreases gradually. When L/H = 2, the heat exchange tube has a better comprehensive performance. With the increase of the angle of attack (β) of the vortex generator, the PEC increases at first and then decreases. When the angle of attack β = 30°, the PEC has the maximum value under most cases, and the heat exchanger tube has the best comprehensive performance. [ABSTRACT FROM AUTHOR]

In the cases of Reynolds number Re=3 000~50 000, Stokes number Stk=0.1~10, Dean number De=1 400~2 800, the orientation and deposition characteristics of cylindrical particles with aspect ratio β=2~12 in turbulent flow in curved tubes were studied. The motion of cylindrical particles was described under the slender body theory combined with Newton’s 2nd law. The orientation distribution function of cylindrical particles was given by the Fokker Planck equation. The mean velocity of the flow was obtained by solving the Reynolds-averaged Navier-Stokes equation and the Reynolds stress equation. The turbulent fluctuating velocity acting on particles was described with the kinetic simulation sweeping model. By solving the equations of the turbulent flow, the particle motion and the orientation distribution function, the orientation distributions of particles on the cross sections in different axial positions and the outlet were obtained and analyzed. The effects of various parameters on the deposition rate of particles were discussed. The results showed that, the main axis of particles turns toward the flow direction with the increase of Stk and β, and the decrease of De and Re. The deposition rate of particles increases with De, Re and β. However, it shows a non-monotonic trend with the change of Stk. The work has reference values for practical engineering application. [ABSTRACT FROM AUTHOR]

Copyright of Advances in New & Renewable Energy is the property of Editorial Office of Advances in New & Renewable Energy and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas & Oil is the property of Editorial Department of Natural Gas & Oil and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Clean Coal Technology is the property of Clean Coal Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal Of Sichuan University (Natural Sciences Division) / Sichuan Daxue Xuebao-Ziran Kexueban is the property of Editorial Department of Journal of Sichuan University Natural Science Edition and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Control Theory & Applications / Kongzhi Lilun Yu Yinyong is the property of Editorial Department of Control Theory & Applications and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Egg quality depends strictly on the storage environment after acquisition. The concentration of CO2 has an important influence on the respiration and freshness of eggs during storage. This study aims to further observe the diffusion and freshness changes of CO2 released from egg respiration under different CO2 concentrations. The respiration intensity and freshness of stored eggs were measured at the temperature of 25°C, the relative humidity of 65%, the CO2 volume fraction of 1.5%, 3.0%, 4.5%, and air (control group). The egg model was built by UG software. An ICEM CFD software was utilized to establish the fluid domain of the egg released carbon dioxide diffusion, and then divide it into a structural grid. A FLUENT software was selected to complete the diffusion simulation of the first day breathing release CO2 from eggs with different CO2 concentrations. The results show that the law of heavy gas diffusion was followed by the diffusion process of CO2 released from eggs with different CO2 volume fractions. Four stages were divided into: the initial, descending, mixing, and turbulent flow. The diffusion time in each stage was affected by the concentration of external CO2. Specifically, the diffusion amount and speed of CO2 released by egg respiration gradually decreased, with the increase of CO2 concentration in the storage environment. Egg respiration was inhibited, as the outside CO2 concentration increased. There was a significant difference in the respiration intensity and freshness of eggs stored in the external environment with the CO2 volume fraction of 1.5%, 3.0%, and 4.5% (P<0.05) during the entire storage. The inhibitory effect on the respiration intensity of the egg was no longer obvious, and the freshness remained unchanged (P>0.05) when the CO2 volume fraction reached 3.0%. The freshness level of eggs was still above the AA level, when stored under the environment of CO2 volume fraction of 3.0%, and 4.5% for 20 d. Taking economic factors into account, the CO2 volume fraction of 3.0% was better to achieve the optimal freshness of eggs during storage. This study provides new ideas and data support for modified atmosphere preservation of eggs. [ABSTRACT FROM AUTHOR]

As an essential part of riverine, lacustrine, and coastal wetland ecosystems, aquatic vegetation（AV） provides important ecosystem services, and many of the ecosystem services arise as AV has the ability to alter local hydrodynamic conditions. Studies on vegetated flow are helpful not only for scientifically illustrating the environmental and ecological effects of AV but also for guiding the practice of ecological restoration and pollution regulation in rivers and lakes. Considering two kinds of hydrodynamic environments（i.e.,unidirectional open-channel flow and waves）,this paper summarizes the main findings on the influence of AV on flow structures and sediment movement domestically and abroad. Under unidirectional open-channel flow conditions, research on the influence of AV on hydrodynamics has mainly focused on the flow resistance caused by AV and the turbulent flow structures and scales within canopy. Related studies on waves have mainly focused on the effect of AV on wave damping and the mean and turbulent flow structures. Dominated by hydrodynamic conditions, sediment movement under the influence of AV has recently received a lot of attention on the incipient sediment motion and bed load transportation under unidirectional flow conditions and sediment resuspension under waves. [ABSTRACT FROM AUTHOR]

The presence of vegetation changes the flow and thereby modifies the river bedform. This study explores the characteristics of the bedforms and their interactions with the overlaying flow through submerged vegetation. Different types of turbulent flows are generated in a laboratory flume, and the bed topography and turbulent statistical parameters are measured. Results indicate that the bed morphology is characterized by the horseshoe scour holes around individual plants and the gully-ridge pattern in the wakes. These bedform features do not significantly influence the hydrodynamics in the free shear flow. However, the horseshoe scour holes, the gully-ridge pattern and sand ripples intensify the vertical variation of the flow velocity and promote the vertical momentum exchange in the bed shear flow. Besides, the horseshoe scour holes, the gully-ridge pattern and sand ripples persist in the‘quasi dual-flow’regime. These bedforms are found to promote momentum exchange and inhibit turbulent sweeping within the canopy layer. Above the vegetation canopy, however, these bed features are found to inhibit momentum exchange and promote turbulent ejection. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Harbin Institute of Technology. Social Sciences Edition / Haerbin Gongye Daxue Xuebao. Shehui Kexue Ban is the property of Harbin Institute of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Most widely used critical liquid-carrying flow prediction models are Turner model and Li Min model. They both do not consider the influence of flow conditions on the liquid carrying in gas wells and assume the drag coefficient to be a constant. However, the variations of Reynolds number has a great influence on the drag coefficient in highly turbulent flow region, the discrepancies of the two models calculation with actual data exist. Aiming at this problem, considering the effect of drop deformation on the minimum critical flow rate and introducing GP model calculating the drag coefficient in highly turbulent flow regime, a new prediction model for continuous liquid-carrying in gas wells was established. The new model simplifies the calculation of droplet deformation parameters and considers the variations of the drag coefficient with Reynolds numbers in highly turbulent flow region. The new model is compared with Turner model and Li Min model, and validated with the actual data. The results show that the new model provides the prediction results in b est coincidence with the actual state of gas wells. In conclusion, critical flow rate of gas wells in highly turbulent flow region can be predicted accurately by the new model, which has a guidance for gas production planning. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Image & Graphics is the property of Editorial Office of Journal of Image & Graphics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To analyze the accuracy and differences of diverse turbulence models in predicting the flow around baffles of self-designed wet dust treatment system, several representative Reynolds Averaged Navier-Stokes (RANS) models of Standard κ-ε, RNG κ-ε, SST κ-ω and RSM were selected to simulate the vortex flow induced by arc baffles respectively, and the simulation result was also compared with experiment data. The simulation parameters mainly include the vortex structure, pressure distribution and velocity distribution, and the results show that all the simulations based on the four turbulence models can roughly describe the main characteristics of the vortex flow around baffles, while the Standard κ-ε and RNG κ-ε modes are more accurate. For the pressure drop and total pressure distribution, the results of Standard κ-ε model deviate from the other models, and the decreasing sequence of predicted values is Standard κ-ε，RNG κ-ε，RSM and SST κ-ω. The predicted results of RNG κ-ε model for longitudinal velocity are the closest to the experiment data, while the accuracy of SST κ-ω model for predicting near wall flow and lateral velocity is relatively high. [ABSTRACT FROM AUTHOR]

Pump system with slanted extension shaft is one of the main pump systems in large low head pump station. In order to improve the flow pattern in the slanted outlet conduit and increase hydraulic performance of pump system, the three dimension turbulent flow field was calculated for the pump system with 20° shaft extension in a large low head pump station based on the Reynolds-averaged Navier-Stokes equations and standard k- turbulent model. By the method of numerical simulation, flow fields in outlet conduits were analyzed and compared for 4 kinds of calculation schemes which were straight outlet conduit without rotation, S-shaped curve outlet conduit without rotation, straight outlet conduit with rotation and S-shaped curve outlet conduit with rotation. Based on the analyses, the cause of serious bias flow in the slanted outlet conduit was analyzed. According to the influence of length of middle pier on the bias coefficient and hydraulic loss of the slanted outlet conduit, the method of solving the bias flow problem was put forward, and the fittest middle pier length was chosen, and the hydraulic performance of the pump system was tested. The research results showed that there was serious bias flow in slanted outlet conduit when the length of middle pier was 14 m. Looking from the direction of downstream flow, the main flow was obviously skewed to the left side of the slanted outlet conduit, while a large range of vortex area appeared in the lower right part of the outlet conduit, and the discharge of the left hole was obviously than that of the right hole. There was no bias flow in the straight and the S-shaped curved outlet conduits when the flow at the conduit inlet with no rotation. There was no bias flow in the straight outlet conduit while there was obviously bias flow in the S-shaped curved outlet conduit when the flow at the conduit inlet with rotation. Therefore, the flow with larger residual circumferential velocity component at the guide vane outlet enters into the S-shaped curved outlet conduit in a spiral shape was the cause of serious bias flow in the slanted outlet conduit. The results also showed that the middle pier length had a significant influence on bias coefficient and hydraulic loss of the slanted outlet conduit. When the middle pier length was 14 m, the conduit bias coefficient and hydraulic loss were large. Along with the middle pier length increased, the conduit hydraulic loss decreased firstly and then increased, the conduit bias coefficient decreased gradually. When the middle pier length was 23.35 m, the conduit bias coefficient was smaller than 1, the discharge of right side was bigger than that of left side in the outlet conduit, the main flow was skewed to the right hole. The discharge from the left and right sides of the outlet conduit is basically equal when the middle pier was lengthened to an appropriate value. The slanted outlet conduit scheme with proper extension of the middle pier length had been verified by the model test of the pump system. The efficiency of optimal operation point for the pump system with slanted extension shaft reached 80.56%, the model test results were basically the same with the numerical simulation results. The pressure values on the left and right sides were very close at corresponding time and the pressure variation trends were basically the same. These model test results indicated that the flow pattern of left and right sides were nearly the same and the expected rectification effect was achieved. The slanted outlet conduit scheme whose middle pier length was 23.35 m had been recognized by the relevant engineering design institute and applied to the engineering practice. [ABSTRACT FROM AUTHOR]

In this paper, an entropy analysis and design optimization methodology is combined with multi-objective airfoil shape optimization to demonstrate the impact of entropy generation on aerodynamic designs. Model equations for the calculation of the local entropy generation rate in turbulent flows are presented by extending the Reynolds-averaging procedure to the entropy balance equation. We use the CST parametric method to model the airfoil configuration and combine the CFD solver with multi-objective optimization algorithm respectively, to compute aerodynamics quantities such as lift-drag ratio and entropy generation rate. We obtain the optimized airfoils that maximize lift-drag ratios and minimize entropy generation rates as optimization objectives. Moreover, the present method is compared with the traditional method. From the multi-objective solutions, a designer can select a set of airfoil shapes with low relative entropy generation, small actuation cost, and improved aerodynamic performance at the design conditions. The optimized results unfold that, the proposed method is capable of realizing better performance in practical aerodynamic optimization, with the features of strong global convergence and improved aerodynamic performance in the increase of lift-drag ratio and the decrease of entropy generation rate, compared with the initial population. [ABSTRACT FROM AUTHOR]

Sand barrier is easy to be buried by sand at the beginning of the sand barrier setting and it will lose wind-preventing and sand fixation function when it is buried deeper, but moderate sand bury can improve protect effect while sand burial will help the sand barrier to form a stable protective structure. So it is conducive to understanding the sand burial mechanism and the change law of protective benefits caused by sand burial. In order to study the difference of wind-preventing and sand fixation of different depth sand burial of sand barrier, the research conducted wind tunnel simulation and field experiment. The laws of wind flow field and sediment transport flux in surface layer of the protection zone which was protected by sandbag sand barrier under the condition of bare, shallow and deep sand buried were studied, and the mobile sand dunes without sand barrier was taken as a control. In the wind tunnel test, the variation of the near-surface airflow field, wind speed profile, sediment transport rate and sediment transport height during the sand burial process were analyzed. Sandbag sand barriers were set up in the windward slopes of mobile sand dunes and wind erosion resistance effects of the three sand burial states were tested. The research results showed that with the sand barrier experienced the process of being bare-shallow-deep sand burial, 1) the variation of the airflow field was gradually and steadily in the near-surface layer, and the turbulent flow was reduced significantly, multiple low-speed settlement areas appeared at the right rear when it was bare, and disappeared when it was shallow burial; 2) Both of effective protecting distance and height of transit flow were decreased , that were at least 70 cm and 15 cm of the leeward side of the sand barrier when it was bare, but fell below 50 cm and 7 cm respectively when it was deep burial; 3) The wind speed distribution curve of the near surface layer on the windward and leeward side of the sand barrier did not obey the logarithmic function, and the wind speed profile was volatility change with the height, as the sand barrier was gradually buried by sand, wind speed profile was the same as that of the control and obeyed the law of logarithmic distribution; 4) The height of transporting sediment discharge on protection zone of the sand barriers decreased significantly (P<0.01), height of transporting sediment discharge decreased from 42 cm (bare) to 34 cm (shallow burial) and finally to 28cm (deep burial), and the distribution height of the control was 24 cm; 5) Field experiments of three burial depths showed that wind erosion depth of bare, shallow and deep buried sandbag sand barriers in protection area showed a decreasing trend two years after setting up, the depth of wind erosion decreased by 18.53%, 72.97% and 80.40% respectively compared with the control. The research can provide theoretical support for optimization of sand barrier height and improvement of applied technology. [ABSTRACT FROM AUTHOR]

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