Detecting multiple parameters in salt spray environments is critical,as it significantly enhances the stability and reliability of real-time corrosion monitoring systems.However,current sensor strategies for detecting...Detecting multiple parameters in salt spray environments is critical,as it significantly enhances the stability and reliability of real-time corrosion monitoring systems.However,current sensor strategies for detecting salt spray parameters face challenges such as poor timeliness,short lifespan,and low detection accuracy.This work introduces a multi-parameter micro-nano sensor based on Micro-Electro-Mechanical Systems(MEMS)technology,which integrates temperature,humidity,and conductivity detection units.Through a systematic characterization of the sensor’s performance,the sensor demonstrates excellent linearity,ideal detection ranges,and satisfactory accuracies with detection accuracies of±0.1℃ for temperature,±2%RH for humidity,and±0.1 mS/cm for conductivity.This sensor offers a practical strategy for calculating the instantaneous corrosion rate of aircraft over the ocean.Additionally,based on the positive correlation between the three parameters and the liquid film thickness,a critical threshold determination method for the dynamic behavior of the sensor surface liquid film is further explored.This method macroscopically distinguishes the phase transition boundary between dry and wet states of the liquid film,offering a theoretical foundation for differentiated corrosion rate assessment and improved corrosion prediction accuracy.Highprecision monitoring of environmental parameters during long-term salt spray and atmospheric exposure experiments is achieved using a self-developed online testing system.Real-time data compensation is also provided to improve the sensor’s stability and accuracy.Consequently,the proposed high-precision,miniaturized,and massproducible multi-parameter sensor holds great promise as a competitive device for detecting salt spray environmental parameters in real-time corrosion monitoring systems for the aerospace field.展开更多
The latest version of sea spray flux parameterization scheme developed by Andreas is coupled with the PSU/NCAR model MM5 in this paper. A western Pacific tropical cyclone named Nabi in 2005 is simulated using this cou...The latest version of sea spray flux parameterization scheme developed by Andreas is coupled with the PSU/NCAR model MM5 in this paper. A western Pacific tropical cyclone named Nabi in 2005 is simulated using this coupled air-sea spray modeling system to study the impacts of sea spray evaporation on the evolution of tropical cyclones. The results demonstrate that sea spray can lead to a significant increase of heat fluxes in the air-sea interface, especially the latent heat flux, the maximum of which can increase by up to about 35% - 80% The latent heat flux seems to be more important than the sensible heat flux for the evolution of tropical cyclones. Regardless of whether sea spray fluxes have been considered, the model can always simulate the track of Nabi well, which seems to indicate that sea spray has little impact on the movement of tropical cyclones. However, with sea spray fluxes taken into account in the model, the intensity of a simulated tropical cyclone can have significant increase. Due to the enhancement of water vapor and heat from the sea surface to the air caused by sea spray, the warm core structure is better-defined, the minimum sea level pressure decreases and the vertical speed is stronger around the eye in the experiments, which is propitious to the development and evolution of tropical cyclones.展开更多
In order to obtain appropriate spray pressure and enhance the spraying and dust removal efficiency, various factors including the dust characteristics, nozzle spraying angle, effective spraying range, water consumptio...In order to obtain appropriate spray pressure and enhance the spraying and dust removal efficiency, various factors including the dust characteristics, nozzle spraying angle, effective spraying range, water consumption and droplet size are taken into account. The dust characteristics from different mines and atomization parameters of different pressure nozzles were measured. It was found that the internal pressure of coal cutters and roadheaders should be kept at 2 MPa, which could ensure large droplet size, large spraying angle and low water consumption and hence realizing a large-area covering and capture for large particle dusts. However, the external spray pressure should be kept at 4 MPa for smaller droplet size and longer effective spraying range, leading to effective dust removal in the operator zone. The spray pressure of support moving, drawing opening, and stage loader on a fully mechanized caving face and stage loader on a fully mechanized driving face should be kept at 8 MPa, under which the nozzles have long effective spraying range, high water flow and small droplet size for the rapid capture of instantaneous, high-concentration and small size dust groups. From the applications on the caving and driving faces in the coal mines, it is indicated that the optimization of spray pressure in different spraying positions could effectively enhance dust removal efficiency. Selecting appropriate nozzles according to the dust characteristics at different positions is also favorable for dust removal efficiency. With the selected nozzles under optimal pressures, the removal rates of both total dust and respirable dust could reach over70%, showing a significant de-dusting effect.展开更多
In this work,the formation mechanism of the droplet-to-granule was investigated in detail based on mold powder manufacturing.A specific mathematical model of two-stage spray drying was established to describe droplet ...In this work,the formation mechanism of the droplet-to-granule was investigated in detail based on mold powder manufacturing.A specific mathematical model of two-stage spray drying was established to describe droplet and granule motion,heat and mass transfer,and granule morphology during spray drying.Then,the relationships between spray drying parameters(inlet temperature,atomization pres-sure,slurry mass flow rate)and the properties of the drying tower(temperature and velocity fields)and mold powder granules(temperature,evaporation rates,moisture content,and diameter)were simulated and calculated using ANSYS/Fluent software.To ensure that the granule size of mold powder was controlled within the ideal range(0.2-0.6 mm)for producing granules with appropriate mechanical and metallurgical properties,the following optimum spray drying parameters were chosen based on the results of the numerical simulation:inlet temperatures,873 K;slurry atomization pressure,1.8 MPa;slurry mass flow rate,0.05 kg s-1.Among these parameters,the slurry mass flow rate has the most significant effect on granule size.展开更多
In this experimental study, chromium oxide powder was sprayed on a low-carbon steel substrate using the atmospheric plasma spray process. The current and standoff distances(SODs) were varied to study their effect on t...In this experimental study, chromium oxide powder was sprayed on a low-carbon steel substrate using the atmospheric plasma spray process. The current and standoff distances(SODs) were varied to study their effect on the fracture toughness of the coatings. Theoretically, as the arc current increases, the melting of the ceramic oxide should increase and this in turn should lead to the formation of a dense coating. However,it was observed that if the arc power is too high and because the particle size of the powder is small(approximately 30 μm), the particles tend to fly away from the plasma core. Similarly, an appropriate SOD should provide the particles with more melting time, thus resulting in a dense coating. On the other hand, a larger SOD leads to the solidification of the molten particles before the droplets can reach the substrate. All these effects may lead to substantial variation in the fracture toughness of the coating. The present paper attempts to correlate the plasma spraying parameters and microstructure of the coating with the fracture toughness and other primary coating properties.展开更多
基金supported by the grant from the National Science Foundation of China(62271272)the Open Fund Project of Key Laboratory of Ocean Observation Technology,MNR(2023klootA09)sponsored by Ningbo Science and Technology Project(2022Z092).
文摘Detecting multiple parameters in salt spray environments is critical,as it significantly enhances the stability and reliability of real-time corrosion monitoring systems.However,current sensor strategies for detecting salt spray parameters face challenges such as poor timeliness,short lifespan,and low detection accuracy.This work introduces a multi-parameter micro-nano sensor based on Micro-Electro-Mechanical Systems(MEMS)technology,which integrates temperature,humidity,and conductivity detection units.Through a systematic characterization of the sensor’s performance,the sensor demonstrates excellent linearity,ideal detection ranges,and satisfactory accuracies with detection accuracies of±0.1℃ for temperature,±2%RH for humidity,and±0.1 mS/cm for conductivity.This sensor offers a practical strategy for calculating the instantaneous corrosion rate of aircraft over the ocean.Additionally,based on the positive correlation between the three parameters and the liquid film thickness,a critical threshold determination method for the dynamic behavior of the sensor surface liquid film is further explored.This method macroscopically distinguishes the phase transition boundary between dry and wet states of the liquid film,offering a theoretical foundation for differentiated corrosion rate assessment and improved corrosion prediction accuracy.Highprecision monitoring of environmental parameters during long-term salt spray and atmospheric exposure experiments is achieved using a self-developed online testing system.Real-time data compensation is also provided to improve the sensor’s stability and accuracy.Consequently,the proposed high-precision,miniaturized,and massproducible multi-parameter sensor holds great promise as a competitive device for detecting salt spray environmental parameters in real-time corrosion monitoring systems for the aerospace field.
基金Key Program of National Natural Science Foundation of China (40830235, 40333025)State Key Development Program of Basic Research (973 Program) of China (2004CB418301)
文摘The latest version of sea spray flux parameterization scheme developed by Andreas is coupled with the PSU/NCAR model MM5 in this paper. A western Pacific tropical cyclone named Nabi in 2005 is simulated using this coupled air-sea spray modeling system to study the impacts of sea spray evaporation on the evolution of tropical cyclones. The results demonstrate that sea spray can lead to a significant increase of heat fluxes in the air-sea interface, especially the latent heat flux, the maximum of which can increase by up to about 35% - 80% The latent heat flux seems to be more important than the sensible heat flux for the evolution of tropical cyclones. Regardless of whether sea spray fluxes have been considered, the model can always simulate the track of Nabi well, which seems to indicate that sea spray has little impact on the movement of tropical cyclones. However, with sea spray fluxes taken into account in the model, the intensity of a simulated tropical cyclone can have significant increase. Due to the enhancement of water vapor and heat from the sea surface to the air caused by sea spray, the warm core structure is better-defined, the minimum sea level pressure decreases and the vertical speed is stronger around the eye in the experiments, which is propitious to the development and evolution of tropical cyclones.
基金support from the National Natural Science Foundation of China (Nos.U1261205, 51474139 and 51204103)the Science and Technology Development Plan of Shandong Province (No.2013GSF12004)the Excellent Young Scientific Talents Project of Shandong University of Science and Technology (No.2014JQJH106)
文摘In order to obtain appropriate spray pressure and enhance the spraying and dust removal efficiency, various factors including the dust characteristics, nozzle spraying angle, effective spraying range, water consumption and droplet size are taken into account. The dust characteristics from different mines and atomization parameters of different pressure nozzles were measured. It was found that the internal pressure of coal cutters and roadheaders should be kept at 2 MPa, which could ensure large droplet size, large spraying angle and low water consumption and hence realizing a large-area covering and capture for large particle dusts. However, the external spray pressure should be kept at 4 MPa for smaller droplet size and longer effective spraying range, leading to effective dust removal in the operator zone. The spray pressure of support moving, drawing opening, and stage loader on a fully mechanized caving face and stage loader on a fully mechanized driving face should be kept at 8 MPa, under which the nozzles have long effective spraying range, high water flow and small droplet size for the rapid capture of instantaneous, high-concentration and small size dust groups. From the applications on the caving and driving faces in the coal mines, it is indicated that the optimization of spray pressure in different spraying positions could effectively enhance dust removal efficiency. Selecting appropriate nozzles according to the dust characteristics at different positions is also favorable for dust removal efficiency. With the selected nozzles under optimal pressures, the removal rates of both total dust and respirable dust could reach over70%, showing a significant de-dusting effect.
基金the financial support from the National Natural Science Foundation of China(grant No.52274319)the Youth Foundation of Guizhou Academy of Sciences,China(grant No.202147).
文摘In this work,the formation mechanism of the droplet-to-granule was investigated in detail based on mold powder manufacturing.A specific mathematical model of two-stage spray drying was established to describe droplet and granule motion,heat and mass transfer,and granule morphology during spray drying.Then,the relationships between spray drying parameters(inlet temperature,atomization pres-sure,slurry mass flow rate)and the properties of the drying tower(temperature and velocity fields)and mold powder granules(temperature,evaporation rates,moisture content,and diameter)were simulated and calculated using ANSYS/Fluent software.To ensure that the granule size of mold powder was controlled within the ideal range(0.2-0.6 mm)for producing granules with appropriate mechanical and metallurgical properties,the following optimum spray drying parameters were chosen based on the results of the numerical simulation:inlet temperatures,873 K;slurry atomization pressure,1.8 MPa;slurry mass flow rate,0.05 kg s-1.Among these parameters,the slurry mass flow rate has the most significant effect on granule size.
文摘In this experimental study, chromium oxide powder was sprayed on a low-carbon steel substrate using the atmospheric plasma spray process. The current and standoff distances(SODs) were varied to study their effect on the fracture toughness of the coatings. Theoretically, as the arc current increases, the melting of the ceramic oxide should increase and this in turn should lead to the formation of a dense coating. However,it was observed that if the arc power is too high and because the particle size of the powder is small(approximately 30 μm), the particles tend to fly away from the plasma core. Similarly, an appropriate SOD should provide the particles with more melting time, thus resulting in a dense coating. On the other hand, a larger SOD leads to the solidification of the molten particles before the droplets can reach the substrate. All these effects may lead to substantial variation in the fracture toughness of the coating. The present paper attempts to correlate the plasma spraying parameters and microstructure of the coating with the fracture toughness and other primary coating properties.
