Considering the problems of poor straw mulching performance,low soil crushing rate and poor straw mulching performance of the traditional rotary tiller on saline-alkali soils,a two-axis layered rotary stubble cutter f...Considering the problems of poor straw mulching performance,low soil crushing rate and poor straw mulching performance of the traditional rotary tiller on saline-alkali soils,a two-axis layered rotary stubble cutter for saline-alkali soils with front-axis positive rotation of the front axle and rear-axis counter-rotation of the rear axle was developed,focusing on the kinetic properties of the straw and soil under positive and counter-rotation.In addition,the most important structural parameters and the arrangement of the front-axis stubble cutting knife and the rear-axis return knife were analyzed and determined.Hertz-Mindlin with bonding was used to create a discrete element model of the agglomerate of implement,straw and soil.The forward speed,horizontal distance and vertical distance were used as test factors,and the straw return rate and soil fragmentation rate were used as test indexes to analyze the straw-soil transport law under different operating parameters from a microscopic point of view,and then Design-Expert was used to conduct the test 1.07 km/h,horizontal distance of 569.55 mm,vertical distance of 176.59 mm.To validate the performance of the two-axis,layered rotary tiller,a field trial was conducted and the results show that the straw return ratio was(91.59±0.41)%,soil fragmentation ratio was(91.90±0.29)%and tillage depth stability was(91.52±0.46)%,which met the requirements for peanut seedbed preparation on saline-alkali land.展开更多
Floating offshore wind turbines(FOWTs)are a promising offshore renewable energy harvesting facility but requesting multiple-disciplinary analysis for their dynamic performance predictions.However,engineering-fidelity ...Floating offshore wind turbines(FOWTs)are a promising offshore renewable energy harvesting facility but requesting multiple-disciplinary analysis for their dynamic performance predictions.However,engineering-fidelity level tools and the empirical parameters pose challenges due to the strong nonlinear coupling effects of FOWTs.A novel method,named SADA,was proposed by Chen and Hu(2021)for optimizing the design and dynamic performance prediction of FOWTs in combination with AI technology.In the SADA method,the concept of Key Disciplinary Parameters(KDPs)is also proposed,and it is of crucial importance in the SADA method.The purpose of this paper is to make an in-depth investigation of the characters of KDPs and the internal correlations between different KDPs in the dynamic performance prediction of FOWTs.Firstly,a brief description of SADA is given,and the basin experimental data are used to conduct the training process of SADA.Secondly,categories and boundary conditions of KDPs are introduced.Three types of KDPs are given,and different boundary conditions are used to analyze KDPs.The results show that the wind and current in Environmental KDPs are strongly correlated with the percentage difference of dynamic response rather than that by wave parameters.In general,the optimization results of SADA consider the specific basin environment and the coupling results between different KDPs help the designers further understand the factors that have a more significant impact on the FOWTs system in a specific domain.展开更多
基金sponsored by the Shandong Province Key R&D Program(Major Science and Technology Innovation Project)(Grant No.2021CXGC010813)Saline land tillage mechanization equipment research and development,manufacturing and popularization of application(Grant No.NJYTHSD-202314).
文摘Considering the problems of poor straw mulching performance,low soil crushing rate and poor straw mulching performance of the traditional rotary tiller on saline-alkali soils,a two-axis layered rotary stubble cutter for saline-alkali soils with front-axis positive rotation of the front axle and rear-axis counter-rotation of the rear axle was developed,focusing on the kinetic properties of the straw and soil under positive and counter-rotation.In addition,the most important structural parameters and the arrangement of the front-axis stubble cutting knife and the rear-axis return knife were analyzed and determined.Hertz-Mindlin with bonding was used to create a discrete element model of the agglomerate of implement,straw and soil.The forward speed,horizontal distance and vertical distance were used as test factors,and the straw return rate and soil fragmentation rate were used as test indexes to analyze the straw-soil transport law under different operating parameters from a microscopic point of view,and then Design-Expert was used to conduct the test 1.07 km/h,horizontal distance of 569.55 mm,vertical distance of 176.59 mm.To validate the performance of the two-axis,layered rotary tiller,a field trial was conducted and the results show that the straw return ratio was(91.59±0.41)%,soil fragmentation ratio was(91.90±0.29)%and tillage depth stability was(91.52±0.46)%,which met the requirements for peanut seedbed preparation on saline-alkali land.
文摘Floating offshore wind turbines(FOWTs)are a promising offshore renewable energy harvesting facility but requesting multiple-disciplinary analysis for their dynamic performance predictions.However,engineering-fidelity level tools and the empirical parameters pose challenges due to the strong nonlinear coupling effects of FOWTs.A novel method,named SADA,was proposed by Chen and Hu(2021)for optimizing the design and dynamic performance prediction of FOWTs in combination with AI technology.In the SADA method,the concept of Key Disciplinary Parameters(KDPs)is also proposed,and it is of crucial importance in the SADA method.The purpose of this paper is to make an in-depth investigation of the characters of KDPs and the internal correlations between different KDPs in the dynamic performance prediction of FOWTs.Firstly,a brief description of SADA is given,and the basin experimental data are used to conduct the training process of SADA.Secondly,categories and boundary conditions of KDPs are introduced.Three types of KDPs are given,and different boundary conditions are used to analyze KDPs.The results show that the wind and current in Environmental KDPs are strongly correlated with the percentage difference of dynamic response rather than that by wave parameters.In general,the optimization results of SADA consider the specific basin environment and the coupling results between different KDPs help the designers further understand the factors that have a more significant impact on the FOWTs system in a specific domain.
