The blisk is a core component of an aero-engine,and electrochemical machining(ECM)is the primary method for its manufacture.Among several ECM methods for blisks,multi-tool synchronous machining is the most efficient a...The blisk is a core component of an aero-engine,and electrochemical machining(ECM)is the primary method for its manufacture.Among several ECM methods for blisks,multi-tool synchronous machining is the most efficient and advantageous for machining channels.The allowance distribution of the blank after blisk channel machining directly influences the blade profile accuracy.This paper proposes a trajectory control strategy to homogenize the allowance distribution of the blisk channel in multi-tool ECM.The strategy includes the design of the three-dimensional space motion of the tool and blisk,as well as the regulated feed speed.The structural characteristics of the blisk channel and the principle of ECM allow for designing and optimizing the multidimensional trajectory.The electric field simulations elucidate the influence law of the three-axis feed speed on the side gap.An algorithm is adopted to iteratively optimize the speeds for different positions to realize multi-dimensional motion control and allowance homogenization.The proposed trajectory control strategy is applied to ECM experiments for the blisk channel.Compared with the constant feed speed mode,the regulated speed strategy reduces the maximum allowance difference between the convex(CV)profiles by 36.18%and that between the concave(CC)profiles by 37.73%.Subsequently,the one-time ECM of eight blisk channels was successfully realized.The average time for a single channel was 12.5 min,significantly improving the machining efficiency.In conclusion,the proposed method is effective and can be extended for synchronously machining various blisk types with twisted channels.展开更多
A high-aspect-ratio microchannel heat exchanger based on multi-tool milling process was developed. Several slotting cutters were stacked together for simultaneously machining several high-aspect-ratio microchannels wi...A high-aspect-ratio microchannel heat exchanger based on multi-tool milling process was developed. Several slotting cutters were stacked together for simultaneously machining several high-aspect-ratio microchannels with manifold structures. On the basis of multi-tool milling process, the structural design of the manifold side height, microchannel length, width, number, and interval were analyzed. The heat transfer performances of high-aspect-ratio microchannel heat exchangers with two different manifolds were investigated by experiments, and the influencing factors were analyzed. The results indicate that the magnitude of heat transfer area per unit volume dominates the heat transfer performances of plate-type micro heat exchanger, while the velocity distribution between microchannels has little effects on the heat transfer performances.展开更多
机床滑枕是机床的重要部件,滑枕的刚性对机床的加工精度影响很大。针对机床滑枕传统经验设计效率低、静动态特性难以平衡的问题,提出一种融合参数建模与多目标优化的混合设计方法。通过五因素三水平正交试验建立滑枕结构参数的岭回归模...机床滑枕是机床的重要部件,滑枕的刚性对机床的加工精度影响很大。针对机床滑枕传统经验设计效率低、静动态特性难以平衡的问题,提出一种融合参数建模与多目标优化的混合设计方法。通过五因素三水平正交试验建立滑枕结构参数的岭回归模型,结合非支配排序遗传算法(Non-dominated Sorting Genetic Algorithm-Ⅱ,NSGA-Ⅱ)生成Pareto解集,最后采用优劣解距离(Technique for Order Preference by Similarity to an Ideal Solution,TOPSIS)法决策最优参数组合。结果表明,优化后滑枕质量减少了29.3 kg,较优化前降低了4.7%,最大变形降低了5.8%,一阶固有频率保持稳定在553.3 Hz,表明该方法为机床零/部件多参数耦合优化提供了新的参考。展开更多
基金co-supported by the National Natural Science Foundation of China(No.52075253)the National Natural Science Foundation of China for Creative Research Groups(No.51921003)the Industrial Technology Development Program(No.JCKY2021605B026)。
文摘The blisk is a core component of an aero-engine,and electrochemical machining(ECM)is the primary method for its manufacture.Among several ECM methods for blisks,multi-tool synchronous machining is the most efficient and advantageous for machining channels.The allowance distribution of the blank after blisk channel machining directly influences the blade profile accuracy.This paper proposes a trajectory control strategy to homogenize the allowance distribution of the blisk channel in multi-tool ECM.The strategy includes the design of the three-dimensional space motion of the tool and blisk,as well as the regulated feed speed.The structural characteristics of the blisk channel and the principle of ECM allow for designing and optimizing the multidimensional trajectory.The electric field simulations elucidate the influence law of the three-axis feed speed on the side gap.An algorithm is adopted to iteratively optimize the speeds for different positions to realize multi-dimensional motion control and allowance homogenization.The proposed trajectory control strategy is applied to ECM experiments for the blisk channel.Compared with the constant feed speed mode,the regulated speed strategy reduces the maximum allowance difference between the convex(CV)profiles by 36.18%and that between the concave(CC)profiles by 37.73%.Subsequently,the one-time ECM of eight blisk channels was successfully realized.The average time for a single channel was 12.5 min,significantly improving the machining efficiency.In conclusion,the proposed method is effective and can be extended for synchronously machining various blisk types with twisted channels.
基金Projects(50675070 50805052) supported by the National Nature Science Foundation of China+1 种基金Projects(07118064 8451064101000320) supported by the Natural Science Foundation of Guangdong Province
文摘A high-aspect-ratio microchannel heat exchanger based on multi-tool milling process was developed. Several slotting cutters were stacked together for simultaneously machining several high-aspect-ratio microchannels with manifold structures. On the basis of multi-tool milling process, the structural design of the manifold side height, microchannel length, width, number, and interval were analyzed. The heat transfer performances of high-aspect-ratio microchannel heat exchangers with two different manifolds were investigated by experiments, and the influencing factors were analyzed. The results indicate that the magnitude of heat transfer area per unit volume dominates the heat transfer performances of plate-type micro heat exchanger, while the velocity distribution between microchannels has little effects on the heat transfer performances.
文摘机床滑枕是机床的重要部件,滑枕的刚性对机床的加工精度影响很大。针对机床滑枕传统经验设计效率低、静动态特性难以平衡的问题,提出一种融合参数建模与多目标优化的混合设计方法。通过五因素三水平正交试验建立滑枕结构参数的岭回归模型,结合非支配排序遗传算法(Non-dominated Sorting Genetic Algorithm-Ⅱ,NSGA-Ⅱ)生成Pareto解集,最后采用优劣解距离(Technique for Order Preference by Similarity to an Ideal Solution,TOPSIS)法决策最优参数组合。结果表明,优化后滑枕质量减少了29.3 kg,较优化前降低了4.7%,最大变形降低了5.8%,一阶固有频率保持稳定在553.3 Hz,表明该方法为机床零/部件多参数耦合优化提供了新的参考。
