A cold cloud assimilation scheme was developed that fully considers the water substances,i.e.,water vapor,cloud water,rain,ice,snow,and graupel,based on the single-moment WSM6 microphysical scheme and four-dimensional...A cold cloud assimilation scheme was developed that fully considers the water substances,i.e.,water vapor,cloud water,rain,ice,snow,and graupel,based on the single-moment WSM6 microphysical scheme and four-dimensional variational(4D-Var)data assimilation in the Weather Research and Forecasting data assimilation(WRFDA)system.The verification of the regularized WSM6 and its tangent linearity model(TLM)and adjoint mode model(ADM)was proven successful.Two groups of single observation and real sounding data assimilation experiments were set up to further verify the correctness of the assimilation scheme.The results showed that the consideration of ice,snow,and graupel in the assimilation system of the 4D-Var,as opposed to their omission in the warm rain Kessler scheme,allowed the water substances to be reasonably updated,further improving the forecast.Before it can be further applied in the assimilation of observational data,radar reflectivities,and satellite radiances,the cold cloud assimilation scheme needs additional verification,including using conventional ground and sounding observations in the 4D-Var assimilation system.展开更多
Each March is a busy period for textile and apparel industrial fields.In Beijing,three professional exhibitions,along with one China Fashion Week,provide
Impinging jet arrays are extensively used in numerous industrial operations,including the cooling of electronics,turbine blades,and other high-heat flux systems because of their superior heat transfer capabilities.Opt...Impinging jet arrays are extensively used in numerous industrial operations,including the cooling of electronics,turbine blades,and other high-heat flux systems because of their superior heat transfer capabilities.Optimizing the design and operating parameters of such systems is essential to enhance cooling efficiency and achieve uniform pressure distribution,which can lead to improved system performance and energy savings.This paper presents two multi-objective optimization methodologies for a turbulent air jet impingement cooling system.The governing equations are resolved employing the commercial computational fluid dynamics(CFD)software ANSYS Fluent v17.The study focuses on four controlling parameters:Reynolds number(Re),swirl number(S),jet-to-jet separation distance(Z/D),and impingement height(H/D).The effects of these parameters on heat transfer and impingement pressure distribution are investigated.Non-dominated Sorting Genetic Algorithm(NSGA-II)and Weighted Sum Method(WSM)are employed to optimize the controlling parameters for maximum cooling performance.The aim is to identify optimal design parameters and system configurations that enhance heat transfer efficiency while achieving a uniform impingement pressure distribution.These findings have practical implications for applications requiring efficient cooling.The optimized design achieved a 12.28%increase in convective heat transfer efficiency with a local Nusselt number of 113.05 compared to 100.69 in the reference design.Enhanced convective cooling and heat flux were observed in the optimized configuration,particularly in areas of direct jet impingement.Additionally,the optimized design maintained lower wall temperatures,demonstrating more effective thermal dissipation.展开更多
基金supported by the National Key R&D Program of China under Grant Nos.2018YFC1507302 and 2018YFC1506803National Natural Science Foundation of China No.42275171+1 种基金the Liaoning Province Key R&D Program of Liaoning of China under Grant No.2020JH2/10300091the Bohai Rim Meteorological Science Collaborative Innovation Fund under Grant No.QYXM201901.
文摘A cold cloud assimilation scheme was developed that fully considers the water substances,i.e.,water vapor,cloud water,rain,ice,snow,and graupel,based on the single-moment WSM6 microphysical scheme and four-dimensional variational(4D-Var)data assimilation in the Weather Research and Forecasting data assimilation(WRFDA)system.The verification of the regularized WSM6 and its tangent linearity model(TLM)and adjoint mode model(ADM)was proven successful.Two groups of single observation and real sounding data assimilation experiments were set up to further verify the correctness of the assimilation scheme.The results showed that the consideration of ice,snow,and graupel in the assimilation system of the 4D-Var,as opposed to their omission in the warm rain Kessler scheme,allowed the water substances to be reasonably updated,further improving the forecast.Before it can be further applied in the assimilation of observational data,radar reflectivities,and satellite radiances,the cold cloud assimilation scheme needs additional verification,including using conventional ground and sounding observations in the 4D-Var assimilation system.
文摘Each March is a busy period for textile and apparel industrial fields.In Beijing,three professional exhibitions,along with one China Fashion Week,provide
文摘Impinging jet arrays are extensively used in numerous industrial operations,including the cooling of electronics,turbine blades,and other high-heat flux systems because of their superior heat transfer capabilities.Optimizing the design and operating parameters of such systems is essential to enhance cooling efficiency and achieve uniform pressure distribution,which can lead to improved system performance and energy savings.This paper presents two multi-objective optimization methodologies for a turbulent air jet impingement cooling system.The governing equations are resolved employing the commercial computational fluid dynamics(CFD)software ANSYS Fluent v17.The study focuses on four controlling parameters:Reynolds number(Re),swirl number(S),jet-to-jet separation distance(Z/D),and impingement height(H/D).The effects of these parameters on heat transfer and impingement pressure distribution are investigated.Non-dominated Sorting Genetic Algorithm(NSGA-II)and Weighted Sum Method(WSM)are employed to optimize the controlling parameters for maximum cooling performance.The aim is to identify optimal design parameters and system configurations that enhance heat transfer efficiency while achieving a uniform impingement pressure distribution.These findings have practical implications for applications requiring efficient cooling.The optimized design achieved a 12.28%increase in convective heat transfer efficiency with a local Nusselt number of 113.05 compared to 100.69 in the reference design.Enhanced convective cooling and heat flux were observed in the optimized configuration,particularly in areas of direct jet impingement.Additionally,the optimized design maintained lower wall temperatures,demonstrating more effective thermal dissipation.
