The coupling behavior of the imbedded weapon store occurring between the local unsteady flow field round the store and the structure response on the processing of opening its bay-door is simulated by using numerical m...The coupling behavior of the imbedded weapon store occurring between the local unsteady flow field round the store and the structure response on the processing of opening its bay-door is simulated by using numerical method based on computational fluid mechanics(CFD).The transient aerodynamic behaviors when opening door under various flight altitudes and the corresponding structure deformation evolution in the unsteady flow fields are analyzed respectively and presented.The rules of aircraft attitude parameters′impacting to the responses of structure and the bay-door′s opening process are obtained by comparing with the analysis results.These rules can be applied to the structure design of bay-door and route specification of missile when disengaged and launched from within store.展开更多
The streamlined nose length(SNL)plays a crucial role in determining the aerodynamic performance of high-speed trains.An appropriate SNL can not only effectively reduce the magnitude of aerodynamic drag and lift forces...The streamlined nose length(SNL)plays a crucial role in determining the aerodynamic performance of high-speed trains.An appropriate SNL can not only effectively reduce the magnitude of aerodynamic drag and lift forces,but also improve the performance of the high-speed train in tunnel passing and crosswind circumstances.In this study,a numerical simulation of the aerodynamic performance of high-speed trains at a speed of 400 km/h,with varying SNLs,is conducted using the k-ωshear stress transport(SST)turbulence model.The different SNLs include 6.0,7.0,8.0,9.0,9.8,12.0,15.0,and 18.0 m.In order to validate the accuracy of the numerical simulation,its results are compared with wind tunnel test data obtained from the literature.Numerical simulation is carried out using compressible and incompressible gases to determine the effect of gas compressibility on results.The impact of SNL on the aerodynamic performance of the trains is analyzed in terms of aerodynamic forces,velocity,and pressure distributions.In comparison to the original train,the train with a 6.0 m SNL experienced a 10.8%increase in overall aerodynamic resistance.Additionally,the lift forces on the head and tail cars increased by 35.7%and 75.5%,respectively.On the other hand,the train with an 18.0 m SNL exhibited a 16.5%decrease in aerodynamic drag.Furthermore,the lift forces on the head and tail cars decreased by 21.9%and 49.7%,respectively.The aerodynamic drag force of the entire train varies linearly with the SNL,while the aerodynamic lift of the tail car follows a quadratic function in relation to the SNL.展开更多
文摘The coupling behavior of the imbedded weapon store occurring between the local unsteady flow field round the store and the structure response on the processing of opening its bay-door is simulated by using numerical method based on computational fluid mechanics(CFD).The transient aerodynamic behaviors when opening door under various flight altitudes and the corresponding structure deformation evolution in the unsteady flow fields are analyzed respectively and presented.The rules of aircraft attitude parameters′impacting to the responses of structure and the bay-door′s opening process are obtained by comparing with the analysis results.These rules can be applied to the structure design of bay-door and route specification of missile when disengaged and launched from within store.
基金supported by the National Natural Science Foundation of China(No.12372049)the Sichuan Science and Technology Program(No.2023JDRC0062)+1 种基金the Independent Project of State Key Laboratory of Rail Transit Vehicle System(No.2023TPL-T06)the Fundamental Research Funds for the Central Universities,China(No.2682023ZTPY036).
文摘The streamlined nose length(SNL)plays a crucial role in determining the aerodynamic performance of high-speed trains.An appropriate SNL can not only effectively reduce the magnitude of aerodynamic drag and lift forces,but also improve the performance of the high-speed train in tunnel passing and crosswind circumstances.In this study,a numerical simulation of the aerodynamic performance of high-speed trains at a speed of 400 km/h,with varying SNLs,is conducted using the k-ωshear stress transport(SST)turbulence model.The different SNLs include 6.0,7.0,8.0,9.0,9.8,12.0,15.0,and 18.0 m.In order to validate the accuracy of the numerical simulation,its results are compared with wind tunnel test data obtained from the literature.Numerical simulation is carried out using compressible and incompressible gases to determine the effect of gas compressibility on results.The impact of SNL on the aerodynamic performance of the trains is analyzed in terms of aerodynamic forces,velocity,and pressure distributions.In comparison to the original train,the train with a 6.0 m SNL experienced a 10.8%increase in overall aerodynamic resistance.Additionally,the lift forces on the head and tail cars increased by 35.7%and 75.5%,respectively.On the other hand,the train with an 18.0 m SNL exhibited a 16.5%decrease in aerodynamic drag.Furthermore,the lift forces on the head and tail cars decreased by 21.9%and 49.7%,respectively.The aerodynamic drag force of the entire train varies linearly with the SNL,while the aerodynamic lift of the tail car follows a quadratic function in relation to the SNL.
