The titanium alloy strut serves as a key load-bearing component of aircraft landing gear,typically manufactured via forging.The friction condition has important influence on material flow and cavity filling during the...The titanium alloy strut serves as a key load-bearing component of aircraft landing gear,typically manufactured via forging.The friction condition has important influence on material flow and cavity filling during the forging process.Using the previously optimized shape and initial position of preform,the influence of the friction condition(friction factor m=0.1–0.3)on material flow and cavity filling was studied by numerical method with a shear friction model.A novel filling index was defined to reflect material flow into left and right flashes and zoom in on friction-induced results.The results indicate that the workpiece moves rigidly to the right direction,with the displacement decreasing as m increases.When m<0.18,the underfilling defect will occur in the left side of strut forging,while overflow occurs in the right forging die cavity.By combining the filling index and analyses of material flow and filling status,a reasonable friction factor interval of m=0.21–0.24 can be determined.Within this interval,the cavity filling behavior demonstrates robustness,with friction fluctuations exerting minimal influence.展开更多
The alternating wedge strut,serving as both an injector and a vortex generator,has great potential for application in the scramjet combustor.The expansive trailing edge structure can further enhance the mixing perform...The alternating wedge strut,serving as both an injector and a vortex generator,has great potential for application in the scramjet combustor.The expansive trailing edge structure can further enhance the mixing performance of the alternating wedge strut.To enhance the performance of scramjet engines,it is essential to investigate the fuel/air mixing characteristics and mechanism downstream of alternating wedge struts with expansive trailing edges.The research focused on the impact of two different fuel injection schemes on the air/fuel mixing process and plume morphology.The optical diagnostic technique,particle laser-induced fluorescence,was employed to measure fuel plume morphology at various downstream locations under ambient temperature conditions.The results show that the expansive trailing edge significantly enhances the vertical diffusion of the fuel,leading to distinct plume characteristics.Compared to the strut injecting fuel into the edge of the streamwise vortex,the strut injecting fuel into the core of the streamwise vortex results in a larger fuel plume area with a more uniform distribution.Additionally,a streamwise vortex model was established to investigate the vortex dynamics and mixing mechanisms behind the strut from a mechanistic perspective.The simulation results indicate that the model demonstrates good performance in forecasting the dynamics of streamwise vortices and the evolution of fuel plume morphology.展开更多
基金National Natural Science Foundation of China(52375378)National Key Laboratory of Metal Forming Technology and Heavy Equipment(S2308100.W12)Huxiang High-Level Talent Gathering Project of Hunan Province(2021RC5001)。
文摘The titanium alloy strut serves as a key load-bearing component of aircraft landing gear,typically manufactured via forging.The friction condition has important influence on material flow and cavity filling during the forging process.Using the previously optimized shape and initial position of preform,the influence of the friction condition(friction factor m=0.1–0.3)on material flow and cavity filling was studied by numerical method with a shear friction model.A novel filling index was defined to reflect material flow into left and right flashes and zoom in on friction-induced results.The results indicate that the workpiece moves rigidly to the right direction,with the displacement decreasing as m increases.When m<0.18,the underfilling defect will occur in the left side of strut forging,while overflow occurs in the right forging die cavity.By combining the filling index and analyses of material flow and filling status,a reasonable friction factor interval of m=0.21–0.24 can be determined.Within this interval,the cavity filling behavior demonstrates robustness,with friction fluctuations exerting minimal influence.
文摘The alternating wedge strut,serving as both an injector and a vortex generator,has great potential for application in the scramjet combustor.The expansive trailing edge structure can further enhance the mixing performance of the alternating wedge strut.To enhance the performance of scramjet engines,it is essential to investigate the fuel/air mixing characteristics and mechanism downstream of alternating wedge struts with expansive trailing edges.The research focused on the impact of two different fuel injection schemes on the air/fuel mixing process and plume morphology.The optical diagnostic technique,particle laser-induced fluorescence,was employed to measure fuel plume morphology at various downstream locations under ambient temperature conditions.The results show that the expansive trailing edge significantly enhances the vertical diffusion of the fuel,leading to distinct plume characteristics.Compared to the strut injecting fuel into the edge of the streamwise vortex,the strut injecting fuel into the core of the streamwise vortex results in a larger fuel plume area with a more uniform distribution.Additionally,a streamwise vortex model was established to investigate the vortex dynamics and mixing mechanisms behind the strut from a mechanistic perspective.The simulation results indicate that the model demonstrates good performance in forecasting the dynamics of streamwise vortices and the evolution of fuel plume morphology.
