It is very important to develop new air-cushion nozzles so as to raise the heat treatment property of aluminum alloy automobile body sheet(ABS). A geometric model of air-cushion furnace equipment of ABS was built up a...It is very important to develop new air-cushion nozzles so as to raise the heat treatment property of aluminum alloy automobile body sheet(ABS). A geometric model of air-cushion furnace equipment of ABS was built up and flow field was simulated by using k-ε turbulence equations of COMSOL Multi-physics. The influence and regularity of number(n),diameter(d) and arrangement of middle hole,and main control parameters of new air-cushion nozzle on aerodynamic characteristics and flow field were studied. The results show that:1) with n increases,airflow vortexes in air-cushion area increase in multiple; d decreases or n increases,air cushion pressure(p_c) becomes uniform; 2) average of p_c is proportional to pressure in nozzle box(p_t),when n increases,ratio of average of p_c to p_t increases,and when n ≤ 3 and d < b / 2,they have little effect on ratio of p_c average to p_t; 3) when n is an even number,n ≥4,and d ≤ b/2,p_c shows good uniformity; when n is an odd number,the center hole affects p_c uniformity greatly,and,when diameter of center hole is less than b / 4 and diameter of non-center is between b / 4 and b / 2,p_c has good uniformity. A new air-cushion jet model was presented,and the deviation of this new model with simulation data and experimental measured data are less than 7.75% and 7.76%,respectively. The present research is valuable for improving air-cushion stability,Al strip temperature homogeneity,and temperature control precision.展开更多
A three-dimensional （3D） finite element model of air-cushion isolated arch dam is presented with the nonlinear gas-liquid-solid multi-field dynamic coupling effect taken into account.In this model,the displacement f...A three-dimensional （3D） finite element model of air-cushion isolated arch dam is presented with the nonlinear gas-liquid-solid multi-field dynamic coupling effect taken into account.In this model,the displacement formulation in Lagrange method,pressure formulation in Euler method,nonlinear contact model based on Coulomb friction law are applied to the air-cushion,reservoir and contraction joint domain,respectively.The dynamic response of Jinping I arch dam with a height of 305 m is analyzed using the seismic records of the Wenchuan Earthquake in 2008.Numerical results show that the air-cushion isolation reduces significantly the hydrodynamic pressure as well as the opening width for the contraction joints of high arch dam.展开更多
This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV's voyage and turning performance has been done. I...This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV's voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV's movement characteristic basically.展开更多
The process characteristics of heat treatment of aluminum alloy auto body sheet and the working principle of air cushion furnace were introduced.The process position and irreplaceable role of air cushion furnace in th...The process characteristics of heat treatment of aluminum alloy auto body sheet and the working principle of air cushion furnace were introduced.The process position and irreplaceable role of air cushion furnace in the aluminum alloy auto body sheet production was pointed out after the difficulty and key points in the whole production process of auto body sheet were studied.Then the development process of air cushion furnace line of aluminum alloy sheet was reviewed,summarized and divided to two stages.Based on the research of air cushion furnace,the key technology of it was analyzed,then the key points on process,equipment and control models of air cushion furnace for aluminum alloy auto body sheet in future were put forward.With the rapid development of automotive industry,there will be certainly a new upsurge of research and application of air cushion furnace for heat treatment of aluminum alloy auto body sheet.展开更多
The air-flow’s states and ways acted on the technological process of chemical fiber are summed up, which includes chip drying, spinning quenching as well as airjet texturing (air texturing, tangling texturing and bul...The air-flow’s states and ways acted on the technological process of chemical fiber are summed up, which includes chip drying, spinning quenching as well as airjet texturing (air texturing, tangling texturing and bulked continuous filament (BCF)),and the effect of air-flow on the process and quality of chemical fiber is studied,and the action of mechanics and heat on the bulked continuous filament are calculated.展开更多
In this paper,the Reynolds number,velocity,pressureand kinetic energy of the BCF processing hot air-floware analyzed with the help of the aero-dynamic theory,and their distributions inside the texturing tube are ob-ta...In this paper,the Reynolds number,velocity,pressureand kinetic energy of the BCF processing hot air-floware analyzed with the help of the aero-dynamic theory,and their distributions inside the texturing tube are ob-tained by pressure measuring.展开更多
In the present study, the air quality is assessed for the year 2010 regarding to the Total Suspended Particles (TSP) for six cities of Sonora, Mexico, representing the first regional study in Sonora in air quality. Th...In the present study, the air quality is assessed for the year 2010 regarding to the Total Suspended Particles (TSP) for six cities of Sonora, Mexico, representing the first regional study in Sonora in air quality. The assessment used performance indicators and indicators of compliance with the regulations. It is established that in all the cities the maximum limit value of daily concentration of 210 μg/m3 is exceeded, being the percentage of days above the rule of 30%, 78%, 76%, 6%, 3% and 62% for Agua Prieta, Nogales, Puerto Penasco, Hermosillo, Guaymas and Obregón respectively, classifying these days with poor air quality. According to the annualized index used, the air quality was not satisfactory for the period of study in the six cities. Nogales and Puerto Penasco presented the most adverse conditions of air quality with annual average values of TSP of 363 and 345 μg/m3 and maximum daily of 1047 and 1239 μg/m3 (498% and 590% above the norm) respectively. The requirements of coverage that establishes the Mexican Official Standard NOM-025-SSA1-1993 (SSA, 2005) are questioned for its compliance, proposing in this paper a criterion of non-compliance by prioritizing the protection of health and the precautionary principle. It is recommended to implement air quality management programs (PROAIRE) in these cities.展开更多
基金Sponsored by Science and Technology Project of Liaoning Province(Grant No.L2013113)the Fundamental Research Funds for the Central Universities(Grant No.N140703002)
文摘It is very important to develop new air-cushion nozzles so as to raise the heat treatment property of aluminum alloy automobile body sheet(ABS). A geometric model of air-cushion furnace equipment of ABS was built up and flow field was simulated by using k-ε turbulence equations of COMSOL Multi-physics. The influence and regularity of number(n),diameter(d) and arrangement of middle hole,and main control parameters of new air-cushion nozzle on aerodynamic characteristics and flow field were studied. The results show that:1) with n increases,airflow vortexes in air-cushion area increase in multiple; d decreases or n increases,air cushion pressure(p_c) becomes uniform; 2) average of p_c is proportional to pressure in nozzle box(p_t),when n increases,ratio of average of p_c to p_t increases,and when n ≤ 3 and d < b / 2,they have little effect on ratio of p_c average to p_t; 3) when n is an even number,n ≥4,and d ≤ b/2,p_c shows good uniformity; when n is an odd number,the center hole affects p_c uniformity greatly,and,when diameter of center hole is less than b / 4 and diameter of non-center is between b / 4 and b / 2,p_c has good uniformity. A new air-cushion jet model was presented,and the deviation of this new model with simulation data and experimental measured data are less than 7.75% and 7.76%,respectively. The present research is valuable for improving air-cushion stability,Al strip temperature homogeneity,and temperature control precision.
基金supported by the National Natural Science Foun-dation of China (90715026)
文摘A three-dimensional （3D） finite element model of air-cushion isolated arch dam is presented with the nonlinear gas-liquid-solid multi-field dynamic coupling effect taken into account.In this model,the displacement formulation in Lagrange method,pressure formulation in Euler method,nonlinear contact model based on Coulomb friction law are applied to the air-cushion,reservoir and contraction joint domain,respectively.The dynamic response of Jinping I arch dam with a height of 305 m is analyzed using the seismic records of the Wenchuan Earthquake in 2008.Numerical results show that the air-cushion isolation reduces significantly the hydrodynamic pressure as well as the opening width for the contraction joints of high arch dam.
文摘This research is on horizontal plane motion equations of Air Cushion Vehicle (ACV) and its simulation. To investigate this, a lot of simulation study including ACV's voyage and turning performance has been done. It was found that the voyage simulation results were accorded with ACV own characteristic and turning simulation results were accorded with USA ACV's movement characteristic basically.
文摘The process characteristics of heat treatment of aluminum alloy auto body sheet and the working principle of air cushion furnace were introduced.The process position and irreplaceable role of air cushion furnace in the aluminum alloy auto body sheet production was pointed out after the difficulty and key points in the whole production process of auto body sheet were studied.Then the development process of air cushion furnace line of aluminum alloy sheet was reviewed,summarized and divided to two stages.Based on the research of air cushion furnace,the key technology of it was analyzed,then the key points on process,equipment and control models of air cushion furnace for aluminum alloy auto body sheet in future were put forward.With the rapid development of automotive industry,there will be certainly a new upsurge of research and application of air cushion furnace for heat treatment of aluminum alloy auto body sheet.
文摘The air-flow’s states and ways acted on the technological process of chemical fiber are summed up, which includes chip drying, spinning quenching as well as airjet texturing (air texturing, tangling texturing and bulked continuous filament (BCF)),and the effect of air-flow on the process and quality of chemical fiber is studied,and the action of mechanics and heat on the bulked continuous filament are calculated.
文摘In this paper,the Reynolds number,velocity,pressureand kinetic energy of the BCF processing hot air-floware analyzed with the help of the aero-dynamic theory,and their distributions inside the texturing tube are ob-tained by pressure measuring.
基金supported by the Institute of Engineering of the Autonomous University of Baja California,also by to the Industrial Environmental Engineering Program of the Sonora State University,and the Division of Engineering,Department of Chemical Engineering and Metallurgy of the University of Sonora.
文摘In the present study, the air quality is assessed for the year 2010 regarding to the Total Suspended Particles (TSP) for six cities of Sonora, Mexico, representing the first regional study in Sonora in air quality. The assessment used performance indicators and indicators of compliance with the regulations. It is established that in all the cities the maximum limit value of daily concentration of 210 μg/m3 is exceeded, being the percentage of days above the rule of 30%, 78%, 76%, 6%, 3% and 62% for Agua Prieta, Nogales, Puerto Penasco, Hermosillo, Guaymas and Obregón respectively, classifying these days with poor air quality. According to the annualized index used, the air quality was not satisfactory for the period of study in the six cities. Nogales and Puerto Penasco presented the most adverse conditions of air quality with annual average values of TSP of 363 and 345 μg/m3 and maximum daily of 1047 and 1239 μg/m3 (498% and 590% above the norm) respectively. The requirements of coverage that establishes the Mexican Official Standard NOM-025-SSA1-1993 (SSA, 2005) are questioned for its compliance, proposing in this paper a criterion of non-compliance by prioritizing the protection of health and the precautionary principle. It is recommended to implement air quality management programs (PROAIRE) in these cities.
