Squeeze casting(SC)is an advanced net manufacturing process with many advantages for which the quality and properties of the manufactured parts depend strongly on the process parameters.Unfortunately,a universal effic...Squeeze casting(SC)is an advanced net manufacturing process with many advantages for which the quality and properties of the manufactured parts depend strongly on the process parameters.Unfortunately,a universal efficient method for the determination of optimal process parameters is still unavailable.In view of the shortcomings and development needs of the current research methods for the setting of SC process parameters,by consulting and analyzing the recent research literature on SC process parameters and using the CiteSpace literature analysis software,manual reading and statistical analysis,the current state and characteristics of the research methods used for the determination of SC process parameters are summarized.The literature data show that the number of pub-lications in the literature related to the design of SC process parameters generally trends upward albeit with signifi-cant fluctuations.Analysis of the research focus shows that both“mechanical properties”and“microstructure”are the two main subjects in the studies of SC process parameters.With regard to materials,aluminum alloys have been extensively studied.Five methods have been used to obtain SC process parameters:Physical experiments,numeri-cal simulation,modeling optimization,formula calculation,and the use of empirical values.Physical experiments are the main research methods.The main methods for designing SC process parameters are divided into three categories:Fully experimental methods,optimization methods that involve modeling based on experimental data,and theoreti-cal calculation methods that involve establishing an analytical formula.The research characteristics and shortcomings of each method were analyzed.Numerical simulations and model-based optimization have become the new required methods.Considering the development needs and data-driven trends of the SC process,suggestions for the develop-ment of SC process parameter research have been proposed.展开更多
In order to meet the rapid needs of processing square hole in mechanical equipment, the paper expounds the square hole processing method： planetary wheel method, and analyze the principle of tooling structure and pro...In order to meet the rapid needs of processing square hole in mechanical equipment, the paper expounds the square hole processing method： planetary wheel method, and analyze the principle of tooling structure and process with computer graphics parameters design. The results that, as long as the appropriate parameters, using the above method not only can punch the square hole, can also be processed triangle, the five angle and hexagonal regular polygon holes. The square hole processing method can provide theoretical basis and engineering reliable reference for related engineering and technical personnel.展开更多
针对高升阻比风力机翼型前缘曲率半径较大的问题,传统的翼型参数化方法前缘控制能力不足,且基于面元法XFOIL预测精度差的问题,利用增强类函数/形函数转换(CST)参数化方法控制翼型的形状变化、拉丁超立方实验设计、计算流体力学(CFD)流...针对高升阻比风力机翼型前缘曲率半径较大的问题,传统的翼型参数化方法前缘控制能力不足,且基于面元法XFOIL预测精度差的问题,利用增强类函数/形函数转换(CST)参数化方法控制翼型的形状变化、拉丁超立方实验设计、计算流体力学(CFD)流场计算模块、高斯过程回归模型和遗传算法,提出了基于高可信度Reynolds average Navier-Stocks(RANS)和高斯回归模型辅助遗传算法的翼型优化设计方法。结果表明:基于高斯回归模型的翼型优化方法,可以将优化所用CFD计算次数降低一阶,从而大幅度提升优化设计效率。由标准算例超临界翼型RAE2822的降阻设计表明,在百次量级的CFD次数阻力降低43.16%,激波被削弱且升力、力矩和面积严格满足约束。由风力机翼型NACA64618的最大化升阻比优化设计表明,所设计翼型不仅在设计攻角和副设计攻角处升阻比大大增加,在整个小攻角范围内其气动性能都得到了提升,且两个主设计点,无不良阻力的产生。展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.51965006 and 51875209)Guangxi Natural Science Foundation of China(Grant No.2018GXNSFAA050111)+1 种基金Innovation Project of Guangxi Graduate Education of China(Grant No.YCSW2019035)Open Fund of National Engineering Research Center of Near-Shape Forming for Metallic Materials of China(Grant No.2019001).
文摘Squeeze casting(SC)is an advanced net manufacturing process with many advantages for which the quality and properties of the manufactured parts depend strongly on the process parameters.Unfortunately,a universal efficient method for the determination of optimal process parameters is still unavailable.In view of the shortcomings and development needs of the current research methods for the setting of SC process parameters,by consulting and analyzing the recent research literature on SC process parameters and using the CiteSpace literature analysis software,manual reading and statistical analysis,the current state and characteristics of the research methods used for the determination of SC process parameters are summarized.The literature data show that the number of pub-lications in the literature related to the design of SC process parameters generally trends upward albeit with signifi-cant fluctuations.Analysis of the research focus shows that both“mechanical properties”and“microstructure”are the two main subjects in the studies of SC process parameters.With regard to materials,aluminum alloys have been extensively studied.Five methods have been used to obtain SC process parameters:Physical experiments,numeri-cal simulation,modeling optimization,formula calculation,and the use of empirical values.Physical experiments are the main research methods.The main methods for designing SC process parameters are divided into three categories:Fully experimental methods,optimization methods that involve modeling based on experimental data,and theoreti-cal calculation methods that involve establishing an analytical formula.The research characteristics and shortcomings of each method were analyzed.Numerical simulations and model-based optimization have become the new required methods.Considering the development needs and data-driven trends of the SC process,suggestions for the develop-ment of SC process parameter research have been proposed.
文摘In order to meet the rapid needs of processing square hole in mechanical equipment, the paper expounds the square hole processing method： planetary wheel method, and analyze the principle of tooling structure and process with computer graphics parameters design. The results that, as long as the appropriate parameters, using the above method not only can punch the square hole, can also be processed triangle, the five angle and hexagonal regular polygon holes. The square hole processing method can provide theoretical basis and engineering reliable reference for related engineering and technical personnel.
文摘针对高升阻比风力机翼型前缘曲率半径较大的问题,传统的翼型参数化方法前缘控制能力不足,且基于面元法XFOIL预测精度差的问题,利用增强类函数/形函数转换(CST)参数化方法控制翼型的形状变化、拉丁超立方实验设计、计算流体力学(CFD)流场计算模块、高斯过程回归模型和遗传算法,提出了基于高可信度Reynolds average Navier-Stocks(RANS)和高斯回归模型辅助遗传算法的翼型优化设计方法。结果表明:基于高斯回归模型的翼型优化方法,可以将优化所用CFD计算次数降低一阶,从而大幅度提升优化设计效率。由标准算例超临界翼型RAE2822的降阻设计表明,在百次量级的CFD次数阻力降低43.16%,激波被削弱且升力、力矩和面积严格满足约束。由风力机翼型NACA64618的最大化升阻比优化设计表明,所设计翼型不仅在设计攻角和副设计攻角处升阻比大大增加,在整个小攻角范围内其气动性能都得到了提升,且两个主设计点,无不良阻力的产生。
