涡轮叶片内冷通道黏附物磨料流加工去除特性OA

Objectives:The S-shaped internal cooling channels of turbine blades,typically manufactured via the lost foam casting process,are prone to the formation of residual deposits.These residues increase the surface roughness of the flow passages,subsequently restricting airflow and compromising cooling efficiency.Abrasive flow machining(AFM)is a viable post-processing technique to address this.However,the complex S-shaped geometry of these channels results in an unclear understanding of the material removal characteristics of adherent deposits during AFM,posing significant challenges for effective polishing.This study aims to investigate the processing characteristics of simulated powder adhesive residues within S-shaped channels during AFM.The primary objectives are to elucidate the material removal behavior at different locations of the channel and to develop a predictive model for the removal amount.Methods:To simulate the adherent powder residues found in actual channels,small cylindrical platform were added at various strategic locations along an S-shaped channel.Computational simulations were employed to predict the material removal amount on the curved surfaces of these cylindrical platform during the AFM process.Subsequently,a mathematical model for material removal in the finishing of S-shaped channels was established.The influence of different parameters on the removal amount was analyzed by substituting them into this predictive model.Furthermore,to validate the theoretical findings,experimental tests were conducted.The material removal amounts from the small cylindrical platform obtained through experiments were compared and analyzed against the simulation predictions.Results:The results revealed a non-uniform material removal distribution along the S-shaped channel.The material removal on the circular platform was found to be greater at the inlet and outlet sections of the channel.Notably,the removal amount increased abruptly within the curved sections,especially at the first bend.At this first bend,the diameter and height reduction of the cylindrical platform were 44.1%and 43.3%greater,respectively,compared to the straight sections preceding and following the bend.The theoretical predictions for both diameter and height reduction showed a consistent trend with the experimental measurements,despite observable quantitative differences.The deviation between theoretical and experimental values for diameter and height removal was 21.43%and 24.79%,respectively.This indicates that the model possesses a preliminary capability to predict the removal amount at different locations within the channel.Conclusions:This study demonstrates that material removal in AFM for S-shaped channels is highly location-dependent,with curved sections experiencing significantly enhanced removal.The established model,incorporating single abrasive particle dynamics analysis and material removal prediction,shows a consistent trend with experimental data,confirming its fundamental utility.The deviations between theoretical and experimental values highlight areas for future refinement,potentially involving more complex rheological models of the abrasive medium or finer meshing in simulations.Nevertheless,the developed model provides a powerful and valuable tool for determining material removal in AFM processes,offering significant guidance for optimizing the polishing parameters of complex internal channels like those in turbine blades.Future work should focus on model refinement and exploring its application to other complex channel geometries.