With the self-made equipment, the benavior of the splashed slag coating was studied by the thermo-simulation. The influenceof TFe, basicity and heating rate of slag on the occurrence of fractional melting was investig...With the self-made equipment, the benavior of the splashed slag coating was studied by the thermo-simulation. The influenceof TFe, basicity and heating rate of slag on the occurrence of fractional melting was investigated. Furthermore, the composition variationof slag in different stages of the heating process was also discussed, and the mechanism of fractional me1ting was explained. In addition,the exploitation of this phenomenon in practice was also discussed.展开更多
This study determined that the range of the marine splash zone (MSZ) of China’s Qingdao,Zhoushan. Xiamen. Zhanjiang harbour area was about 0-2.4 m above the mean high water level (MHWL) of the seawater that the MSZ c...This study determined that the range of the marine splash zone (MSZ) of China’s Qingdao,Zhoushan. Xiamen. Zhanjiang harbour area was about 0-2.4 m above the mean high water level (MHWL) of the seawater that the MSZ corrosion peak (MSZCP) was usually 0.6- 1.2 m above the MHWL. and was caused by the large salt particle accumulation on the A3 carbon steel test sample surface and by the high frequency altemations of wet and dry environmental conditions around the samples.展开更多
As the first event of soil erosion, rain splash erosion supplies materials for subsequent transportation and en-trainment. The Loess Plateau, the southern hilly region and the Northeast China are subject to serious so...As the first event of soil erosion, rain splash erosion supplies materials for subsequent transportation and en-trainment. The Loess Plateau, the southern hilly region and the Northeast China are subject to serious soil and water loss; however, the characteristics of rain splash erosion in those regions are still unclear. The objectives of the study are to ana-lyze the characteristics of splash erosion on loess soil, red soil, purple soil and black soil, and to discuss the relationship between splash erosion and soil properties. Soil samples spatially distributed in the abovementioned regions were col-lected and underwent simulated rainfalls at a high intensity of 1.2mm/min, lasting for 5, 10, 15, and 20min, respectively. Rain splash and soil crust development were analyzed. It shows that black soil sample from Heilongjiang Province corre-sponds to the minimum splash erosion amount because it has high aggregate content, aggregate stability and organic mat-ter content. Loess soil sample from Inner Mongolia corresponds to the maximum splash erosion amount because it has high content of sand particles. Loess soil sample from Shanxi Province has relatively lower splash erosion amount be-cause it has high silt particle content and low aggregate stability easily to be disrupted under rainfalls with high intensity. Although aggregate contents of red soil and purple soil samples from Hubei and Guangdong provinces are high, the sta-bility is weak and prone to be disrupted, so the splash erosion amount is medium. Splash rate which fluctuates over time is observed because soil crust development follows a cycling processes of formation and disruption. In addition, there are two locations of soil crust development, one appears at the surface, and the other occurs at the subsurface.展开更多
Nugget splash during aluminum alloys spot welding has a detrimental effect on weld nugget integrity, strength and durability of the welded joints. This investigation is performed to identify nugget splash from voltage...Nugget splash during aluminum alloys spot welding has a detrimental effect on weld nugget integrity, strength and durability of the welded joints. This investigation is performed to identify nugget splash from voltage signals because these are easily accessible on-line. In the present work, we propose a novel method based on the wavelet packet transform and its energy spectrum for pattern recognition of splash signal. The result demonstrates that this novel method is more accuracy and a useful way of monitoring the spot welding quality.展开更多
Some differences in slag splashing between BOF steel works in US and China were investigated. The slag composition,melting point, and mineralogical phases of final slags from both countries were studied. The control o...Some differences in slag splashing between BOF steel works in US and China were investigated. The slag composition,melting point, and mineralogical phases of final slags from both countries were studied. The control of slag superheat is important to an effective slag coating.展开更多
The sudden transition from a high-velocity, supercritical open channel flow into a slow-moving sub-critical flow is a hydraulic jump. Such a flow is characterised by a sudden rise of the free-surface, with some strong...The sudden transition from a high-velocity, supercritical open channel flow into a slow-moving sub-critical flow is a hydraulic jump. Such a flow is characterised by a sudden rise of the free-surface, with some strong energy dissipation and air entrainment, waves and spray. New two-phase flow measurements were performed in the developing flow region using a large-size facility operating at large Reynolds numbers. The experimental results demonstrated the complexity of the flow with a developing mixing layer in which entrained bubbles are advected in a high shear stress flow. The relationship between bubble count rates and void fractions was non-unique in the shear zone, supporting earlier observations of some form of double diffusion process between momentum and air bubbles. In the upper region, the flow consisted primarily of water drops and packets sur-rounded by air. Visually significant pray and splashing were significant above the jump roller. The present study is the first com-prehensive study detailing the two-phase flow properties of both the bubbly and spray regions of hydraulic jumps, a first step towards understanding the interactions between bubble entrainment and droplet ejection processes.展开更多
The measured results show that the overexpanded supersonic jet velocity produced by low stagnation pressure (0.53 MPa) attenuates quickly, deviates greatly with smaller impact area and large energy loss. According to ...The measured results show that the overexpanded supersonic jet velocity produced by low stagnation pressure (0.53 MPa) attenuates quickly, deviates greatly with smaller impact area and large energy loss. According to the measured results and the analysis of lashing energy of jet on the bath, the technological parameters of nitrogen flow in slag splashing were proposed.展开更多
The subsea suspended manifold designed to replace the traditional foundation structure with the buoys is a new generation subsea production system that can be suspended at a certain height from the seafloor and rapidl...The subsea suspended manifold designed to replace the traditional foundation structure with the buoys is a new generation subsea production system that can be suspended at a certain height from the seafloor and rapidly recycled by its own buoyancy.Due to complex environmental conditions,its hydrodynamic performance in the splash zone is extremely important for the safety of the whole installation process.In this paper,the mathematical model for the dynamic analysis of the seawater ingress process of the single-layer pre-set horizontal cabin is proposed based on the different center of gravity positions of the buoy.Meanwhile,the theoretical analysis of fiber cable is divided into infinite differential units by the discretization method,and the formulae of the horizontal displacement of the subsea suspended manifold are presented.In addition,the simulations are carried out to verify the rules of the dynamic responses on the subsea suspended manifold system with the consideration of the environmental conditions in the South China Sea.Comparing with the calculated value of the mathematical model of the cabin water ingress,the error of the simulation result by use of FLUENT is about 5.47%.Furthermore,the wave height is greater than the current impact on the lowering manifold system and the azimuth angle of the installation vessel is aligned with the direction of the environmental load.展开更多
To understand the effects of spray parameters on the splashing,cast iron particles were plasma-sprayed onto polished surfaces of aluminum substrate to form single splats.Various plasma arc powers and spray distances w...To understand the effects of spray parameters on the splashing,cast iron particles were plasma-sprayed onto polished surfaces of aluminum substrate to form single splats.Various plasma arc powers and spray distances were applied to adjust the morphology of the splats which was studied using a field emission scanning electron microscope（FESEM）.The experimentalresults showed that the splashing of impinging droplets was significantly restrained for the splats deposited with high arc power（30 k W）and short spray distance（80 mm）.This finding would be beneficialto improving the adhesive strength of the coating.展开更多
Physical properties of molten slag such as viscosity, density and surface tension have a significant influence on the slag splashing process in an oxygen steelmaking converter. Particularly, viscosity determines the s...Physical properties of molten slag such as viscosity, density and surface tension have a significant influence on the slag splashing process in an oxygen steelmaking converter. Particularly, viscosity determines the shear forces that rule droplets formation. Besides, stirring of the molten slag bath strongly depends on this property. In this work, the influence of viscosity on the efficiency of slag splashing is explored by means of transient Computational Fluid Dynamics simulations. Several values of viscosity are employed in the computer experiments. In order to quantify the splashing efficiency as function of slag viscosity, an average slag fraction on the converter walls is defined and calculated. CFD results are compared with those of an empirical expression, and at least qualitative agreement is found.展开更多
Herein, we present the results of our experimental investigation of splashes formed by a frog diving into water from the ground or from a leaf and the accompanying sound generated by the impact of the frog on the wate...Herein, we present the results of our experimental investigation of splashes formed by a frog diving into water from the ground or from a leaf and the accompanying sound generated by the impact of the frog on the water. The experiments are performed by visualizing the flow with a high-speed camera. In addition, we used physical models comprising hydrophilic bodies made from hydrogel or acrylic resin to experimentally study how hydrophilicity affects the splash. In these experiments, we use the degree of swelling to define the hydrophilicity degree. The results show that different splashes are caused by the increase in water-film velocity upon an increase in hydrophilicity. For a body with strong hydrophilicity, at a relatively high film velocity, the water film forms when the body impacts the water surface separates from the body surface. In addition, an aircavity forms when the film separates from the body. We empirically examine the relation between the hydrophilicity degree and film velocity. The results indicate that increased hydrophilicity does not reduce the splash. Therefore, we conclude that reducing of the formation of water from the biomimetic point of view is related to the shape of body.展开更多
The influence of three different blowing conditions on the slag splashing process in a basic oxygen furnace for steelmaking is analyzed here using two-dimensional transient Computational Fluid Dynamics simulations. Fo...The influence of three different blowing conditions on the slag splashing process in a basic oxygen furnace for steelmaking is analyzed here using two-dimensional transient Computational Fluid Dynamics simulations. Four blowing conditions are considered in the computer runs: top blowing, combined blowing using just a bottom centered nozzle, combined blowing using two bottom lateral nozzles, and full combined blowing using the three top and the three bottom nozzles. Computer simulations show that full combined blowing provides greater slag splashing than conventional top blowing.展开更多
文摘With the self-made equipment, the benavior of the splashed slag coating was studied by the thermo-simulation. The influenceof TFe, basicity and heating rate of slag on the occurrence of fractional melting was investigated. Furthermore, the composition variationof slag in different stages of the heating process was also discussed, and the mechanism of fractional me1ting was explained. In addition,the exploitation of this phenomenon in practice was also discussed.
文摘This study determined that the range of the marine splash zone (MSZ) of China’s Qingdao,Zhoushan. Xiamen. Zhanjiang harbour area was about 0-2.4 m above the mean high water level (MHWL) of the seawater that the MSZ corrosion peak (MSZCP) was usually 0.6- 1.2 m above the MHWL. and was caused by the large salt particle accumulation on the A3 carbon steel test sample surface and by the high frequency altemations of wet and dry environmental conditions around the samples.
基金Under the auspices of National Natural Science Foundation of China ( No. 40471084)Innovation Program of Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences (No. 066U0104SZ)State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau (No. 10501-173)
文摘As the first event of soil erosion, rain splash erosion supplies materials for subsequent transportation and en-trainment. The Loess Plateau, the southern hilly region and the Northeast China are subject to serious soil and water loss; however, the characteristics of rain splash erosion in those regions are still unclear. The objectives of the study are to ana-lyze the characteristics of splash erosion on loess soil, red soil, purple soil and black soil, and to discuss the relationship between splash erosion and soil properties. Soil samples spatially distributed in the abovementioned regions were col-lected and underwent simulated rainfalls at a high intensity of 1.2mm/min, lasting for 5, 10, 15, and 20min, respectively. Rain splash and soil crust development were analyzed. It shows that black soil sample from Heilongjiang Province corre-sponds to the minimum splash erosion amount because it has high aggregate content, aggregate stability and organic mat-ter content. Loess soil sample from Inner Mongolia corresponds to the maximum splash erosion amount because it has high content of sand particles. Loess soil sample from Shanxi Province has relatively lower splash erosion amount be-cause it has high silt particle content and low aggregate stability easily to be disrupted under rainfalls with high intensity. Although aggregate contents of red soil and purple soil samples from Hubei and Guangdong provinces are high, the sta-bility is weak and prone to be disrupted, so the splash erosion amount is medium. Splash rate which fluctuates over time is observed because soil crust development follows a cycling processes of formation and disruption. In addition, there are two locations of soil crust development, one appears at the surface, and the other occurs at the subsurface.
基金This work is supported by Nature Science Foundation of Peo-ple ' s Republic of China ( No.50045019).
文摘Nugget splash during aluminum alloys spot welding has a detrimental effect on weld nugget integrity, strength and durability of the welded joints. This investigation is performed to identify nugget splash from voltage signals because these are easily accessible on-line. In the present work, we propose a novel method based on the wavelet packet transform and its energy spectrum for pattern recognition of splash signal. The result demonstrates that this novel method is more accuracy and a useful way of monitoring the spot welding quality.
文摘Some differences in slag splashing between BOF steel works in US and China were investigated. The slag composition,melting point, and mineralogical phases of final slags from both countries were studied. The control of slag superheat is important to an effective slag coating.
文摘The sudden transition from a high-velocity, supercritical open channel flow into a slow-moving sub-critical flow is a hydraulic jump. Such a flow is characterised by a sudden rise of the free-surface, with some strong energy dissipation and air entrainment, waves and spray. New two-phase flow measurements were performed in the developing flow region using a large-size facility operating at large Reynolds numbers. The experimental results demonstrated the complexity of the flow with a developing mixing layer in which entrained bubbles are advected in a high shear stress flow. The relationship between bubble count rates and void fractions was non-unique in the shear zone, supporting earlier observations of some form of double diffusion process between momentum and air bubbles. In the upper region, the flow consisted primarily of water drops and packets sur-rounded by air. Visually significant pray and splashing were significant above the jump roller. The present study is the first com-prehensive study detailing the two-phase flow properties of both the bubbly and spray regions of hydraulic jumps, a first step towards understanding the interactions between bubble entrainment and droplet ejection processes.
文摘The measured results show that the overexpanded supersonic jet velocity produced by low stagnation pressure (0.53 MPa) attenuates quickly, deviates greatly with smaller impact area and large energy loss. According to the measured results and the analysis of lashing energy of jet on the bath, the technological parameters of nitrogen flow in slag splashing were proposed.
基金financially supported by the National Natural Science Foundation of China(Grant No.52071336)the National Key Research and Development Program of China(Grant No.2016YFC0303701)+1 种基金the Ministry of Industry and Information Technology Special Project(Grant No.2018GXB01-07)the CNOOC Limited Shenzhen Branch(Grant No.CCL2019SZPS0541)。
文摘The subsea suspended manifold designed to replace the traditional foundation structure with the buoys is a new generation subsea production system that can be suspended at a certain height from the seafloor and rapidly recycled by its own buoyancy.Due to complex environmental conditions,its hydrodynamic performance in the splash zone is extremely important for the safety of the whole installation process.In this paper,the mathematical model for the dynamic analysis of the seawater ingress process of the single-layer pre-set horizontal cabin is proposed based on the different center of gravity positions of the buoy.Meanwhile,the theoretical analysis of fiber cable is divided into infinite differential units by the discretization method,and the formulae of the horizontal displacement of the subsea suspended manifold are presented.In addition,the simulations are carried out to verify the rules of the dynamic responses on the subsea suspended manifold system with the consideration of the environmental conditions in the South China Sea.Comparing with the calculated value of the mathematical model of the cabin water ingress,the error of the simulation result by use of FLUENT is about 5.47%.Furthermore,the wave height is greater than the current impact on the lowering manifold system and the azimuth angle of the installation vessel is aligned with the direction of the environmental load.
基金Funded by the State Key Laboratory for Mechanical Behavior of Materials(20131312)the Special Fund for Basic Scientific Research of Central CollegesChang’an University(Nos.310831161018,2014G1311093,and 2014G1311082)
文摘To understand the effects of spray parameters on the splashing,cast iron particles were plasma-sprayed onto polished surfaces of aluminum substrate to form single splats.Various plasma arc powers and spray distances were applied to adjust the morphology of the splats which was studied using a field emission scanning electron microscope（FESEM）.The experimentalresults showed that the splashing of impinging droplets was significantly restrained for the splats deposited with high arc power（30 k W）and short spray distance（80 mm）.This finding would be beneficialto improving the adhesive strength of the coating.
文摘Physical properties of molten slag such as viscosity, density and surface tension have a significant influence on the slag splashing process in an oxygen steelmaking converter. Particularly, viscosity determines the shear forces that rule droplets formation. Besides, stirring of the molten slag bath strongly depends on this property. In this work, the influence of viscosity on the efficiency of slag splashing is explored by means of transient Computational Fluid Dynamics simulations. Several values of viscosity are employed in the computer experiments. In order to quantify the splashing efficiency as function of slag viscosity, an average slag fraction on the converter walls is defined and calculated. CFD results are compared with those of an empirical expression, and at least qualitative agreement is found.
文摘Herein, we present the results of our experimental investigation of splashes formed by a frog diving into water from the ground or from a leaf and the accompanying sound generated by the impact of the frog on the water. The experiments are performed by visualizing the flow with a high-speed camera. In addition, we used physical models comprising hydrophilic bodies made from hydrogel or acrylic resin to experimentally study how hydrophilicity affects the splash. In these experiments, we use the degree of swelling to define the hydrophilicity degree. The results show that different splashes are caused by the increase in water-film velocity upon an increase in hydrophilicity. For a body with strong hydrophilicity, at a relatively high film velocity, the water film forms when the body impacts the water surface separates from the body surface. In addition, an aircavity forms when the film separates from the body. We empirically examine the relation between the hydrophilicity degree and film velocity. The results indicate that increased hydrophilicity does not reduce the splash. Therefore, we conclude that reducing of the formation of water from the biomimetic point of view is related to the shape of body.
文摘The influence of three different blowing conditions on the slag splashing process in a basic oxygen furnace for steelmaking is analyzed here using two-dimensional transient Computational Fluid Dynamics simulations. Four blowing conditions are considered in the computer runs: top blowing, combined blowing using just a bottom centered nozzle, combined blowing using two bottom lateral nozzles, and full combined blowing using the three top and the three bottom nozzles. Computer simulations show that full combined blowing provides greater slag splashing than conventional top blowing.
