An atmospheric pressure dielectric barrier discharge （DBD） plasma jet generator using air flow as the feedstock gas was applied to decontaminate the chemical agent surrogates on the surface of aluminum, stainless st...An atmospheric pressure dielectric barrier discharge （DBD） plasma jet generator using air flow as the feedstock gas was applied to decontaminate the chemical agent surrogates on the surface of aluminum, stainless steel or iron plate painted with alkyd or PVC. The experi- mental results of material decontamination show that the residual chemical agent on the material is lower than the permissible value of the National Military Standard of China. In order to test the corrosion effect of the plasma jet on different material surfaces in the decontamination pro-cess, corrosion tests for the materials of polymethyl methacrylate, neoprene, polyvinyl chloride （PVC）, polyethylene （PE）, phenolic resin, iron plate painted with alkyd, stainless steel, aluminum, etc. were carried out, and relevant parameters were examined, including etiolation index, chroma- tism, loss of gloss, corrosion form, etc. The results show that the plasma jet is slightly corrosive for part of the materials, but their performances are not affected. A portable calculator, computer display, mainboard, circuit board of radiogram, and a hygrometer could work normally after being treated by the plasma jet.展开更多
This paper describes the design of a ventilation system to be paired with a carbon capture system. The ventilation system utilizes the geometry of the George C. Wallace tunnel, located in the City of Mobile, Alabama, ...This paper describes the design of a ventilation system to be paired with a carbon capture system. The ventilation system utilizes the geometry of the George C. Wallace tunnel, located in the City of Mobile, Alabama, USA to capture and redirect emissions to a direct air capture (DAC) device to sequester 25% of the total CO2 mass generated from inside the tunnel. The total CO2 mass rate for the westbound traffic between the week-day hours of 7 a.m. and 6 p.m. has been estimated between 2,300 to 3,000 lbs./hr. By sequestering these emissions, the overall surrounding air quality was shown to be improved to a level that mirrors that from the pre-US industrial era of 270 ppm.展开更多
This paper is concerned with three-dimensional numerical simulation of a plunging liquid jet. The transient processes of forming an air cavity around the jet, capturing an initially large air bubble, and the break-up ...This paper is concerned with three-dimensional numerical simulation of a plunging liquid jet. The transient processes of forming an air cavity around the jet, capturing an initially large air bubble, and the break-up of this large toroidal-shaped bubble into smaller bubbles were analyzed. A stabilized finite element method （FEM） was employed under parallel numerical simulations based on adaptive, unstructured grid and coupled with a level-set method to track the interface between air and liquid. These simulations show that the inertia of the liquid jet initially depresses the pool＇s surface, forming an annular air cavity which surrounds the liquid jet. A toroidal liquid eddy which is subse- quently formed in the liquid pool results in air cavity collapse, and in turn entrains air into the liquid pool from the unstable annular air gap region around the liquid jet.展开更多
采用流体体积(Volume of Fluid,VOF)模型和威廉姆斯-霍金斯(Ffowcs Williams and Hawkings,FW-H)模型对浸没排气过程声信号进行数值模拟,研究竖直向下浸没排气过程声信号产生机制及理论依据。将模拟结果与实验结果进行对比,验证模型的...采用流体体积(Volume of Fluid,VOF)模型和威廉姆斯-霍金斯(Ffowcs Williams and Hawkings,FW-H)模型对浸没排气过程声信号进行数值模拟,研究竖直向下浸没排气过程声信号产生机制及理论依据。将模拟结果与实验结果进行对比,验证模型的适用性和准确性。研究结果表明,声信号与流场流动状态相关,气泡间分离和气体再注入过程引起的气泡体积剧烈振动是影响气泡流声信号产生的关键因素。在同一深度处,在径向上声压随位置的变化服从指数衰减,在周向上声信号呈现球源信号传播特点。展开更多
文摘An atmospheric pressure dielectric barrier discharge （DBD） plasma jet generator using air flow as the feedstock gas was applied to decontaminate the chemical agent surrogates on the surface of aluminum, stainless steel or iron plate painted with alkyd or PVC. The experi- mental results of material decontamination show that the residual chemical agent on the material is lower than the permissible value of the National Military Standard of China. In order to test the corrosion effect of the plasma jet on different material surfaces in the decontamination pro-cess, corrosion tests for the materials of polymethyl methacrylate, neoprene, polyvinyl chloride （PVC）, polyethylene （PE）, phenolic resin, iron plate painted with alkyd, stainless steel, aluminum, etc. were carried out, and relevant parameters were examined, including etiolation index, chroma- tism, loss of gloss, corrosion form, etc. The results show that the plasma jet is slightly corrosive for part of the materials, but their performances are not affected. A portable calculator, computer display, mainboard, circuit board of radiogram, and a hygrometer could work normally after being treated by the plasma jet.
文摘This paper describes the design of a ventilation system to be paired with a carbon capture system. The ventilation system utilizes the geometry of the George C. Wallace tunnel, located in the City of Mobile, Alabama, USA to capture and redirect emissions to a direct air capture (DAC) device to sequester 25% of the total CO2 mass generated from inside the tunnel. The total CO2 mass rate for the westbound traffic between the week-day hours of 7 a.m. and 6 p.m. has been estimated between 2,300 to 3,000 lbs./hr. By sequestering these emissions, the overall surrounding air quality was shown to be improved to a level that mirrors that from the pre-US industrial era of 270 ppm.
基金supported by the Office of Naval Research(Grant ONRDC14292111)
文摘This paper is concerned with three-dimensional numerical simulation of a plunging liquid jet. The transient processes of forming an air cavity around the jet, capturing an initially large air bubble, and the break-up of this large toroidal-shaped bubble into smaller bubbles were analyzed. A stabilized finite element method （FEM） was employed under parallel numerical simulations based on adaptive, unstructured grid and coupled with a level-set method to track the interface between air and liquid. These simulations show that the inertia of the liquid jet initially depresses the pool＇s surface, forming an annular air cavity which surrounds the liquid jet. A toroidal liquid eddy which is subse- quently formed in the liquid pool results in air cavity collapse, and in turn entrains air into the liquid pool from the unstable annular air gap region around the liquid jet.
文摘采用流体体积(Volume of Fluid,VOF)模型和威廉姆斯-霍金斯(Ffowcs Williams and Hawkings,FW-H)模型对浸没排气过程声信号进行数值模拟,研究竖直向下浸没排气过程声信号产生机制及理论依据。将模拟结果与实验结果进行对比,验证模型的适用性和准确性。研究结果表明,声信号与流场流动状态相关,气泡间分离和气体再注入过程引起的气泡体积剧烈振动是影响气泡流声信号产生的关键因素。在同一深度处,在径向上声压随位置的变化服从指数衰减,在周向上声信号呈现球源信号传播特点。
