{"title":"机翼内部结构设计与优化研究飞机机翼颤振频率","authors":"N. Akshayraj, B. Ramakumar","doi":"10.4273/ijvss.15.1.14","DOIUrl":null,"url":null,"abstract":"The field of aviation has reached a lot of milestones in the 19th and early 20th century, but the supersonic commercial flights are still a nightmare in 21st century. The major obstacle to reach this milestone is the effect of flutter, which is an aeroelastic phenomenon. It is very important to understand the effect of flutter to reduce it. In this paper effect of flutter is studied by varying the wing internal structures. A scaled down model of the AGARD 445.6 wing having 65A004 aerofoil is designed using Catia V5, for which the experimental data is available for validation. Grid independence study is carried out to obtain more reliable mesh quality. Since flutter is a transient phenomenon time-step independence study is carried out for the time steps of, 0.005s, 0.0025s and 0.00125s. Since there is no difference between the flutter frequency readings for 0.0025 seconds and 0.00125 seconds, 0.0025 seconds is chosen to reduce the computation time. The baseline case is validated with an experimental data available and an error of 0.2-5.32% is observed. Aircraft wing is mainly made out of aluminium alloys. Hence a suitable aluminium alloy is selected by comparing the flutter frequencies. To choose a suitable material, three materials each from wood, alloys and composite are considered i.e., mahogany, aluminium alloy 7075 T6 and Aluminium Metal Matrix Composite (AMC) which are widely used in the Aviation industry. AMC is considered on the basis of frequency charts whose flutter frequency is 30Hz. In this paper in order to supress the flutter we have introduced optimization of ribs and spars in the wing. Variation in the number of ribs, flange width and rib thickness are considered individually. Wing configuration with 10 ribs, flange width of +10% and 10mm rib thickness respectively are having the best flutter frequencies. The wing with above features is further optimised by keeping weight as a constraint by introducing circular and triangular cut-outs section. Flutter frequency for without cut-out, circular cut-out and triangular cut-out are 77.84 Hz, 78.27Hz and 78.43Hz respectively. Hence it is concluded that ribs with triangular cut-outs can be able to reach maximum flutter frequency.","PeriodicalId":14391,"journal":{"name":"International Journal of Vehicle Structures and Systems","volume":"13 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Design and Optimization of Wing Internal Structure to Study the Flutter Frequency of Aircraft Wing\",\"authors\":\"N. Akshayraj, B. Ramakumar\",\"doi\":\"10.4273/ijvss.15.1.14\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"The field of aviation has reached a lot of milestones in the 19th and early 20th century, but the supersonic commercial flights are still a nightmare in 21st century. The major obstacle to reach this milestone is the effect of flutter, which is an aeroelastic phenomenon. It is very important to understand the effect of flutter to reduce it. In this paper effect of flutter is studied by varying the wing internal structures. A scaled down model of the AGARD 445.6 wing having 65A004 aerofoil is designed using Catia V5, for which the experimental data is available for validation. Grid independence study is carried out to obtain more reliable mesh quality. Since flutter is a transient phenomenon time-step independence study is carried out for the time steps of, 0.005s, 0.0025s and 0.00125s. Since there is no difference between the flutter frequency readings for 0.0025 seconds and 0.00125 seconds, 0.0025 seconds is chosen to reduce the computation time. The baseline case is validated with an experimental data available and an error of 0.2-5.32% is observed. Aircraft wing is mainly made out of aluminium alloys. Hence a suitable aluminium alloy is selected by comparing the flutter frequencies. To choose a suitable material, three materials each from wood, alloys and composite are considered i.e., mahogany, aluminium alloy 7075 T6 and Aluminium Metal Matrix Composite (AMC) which are widely used in the Aviation industry. AMC is considered on the basis of frequency charts whose flutter frequency is 30Hz. In this paper in order to supress the flutter we have introduced optimization of ribs and spars in the wing. Variation in the number of ribs, flange width and rib thickness are considered individually. Wing configuration with 10 ribs, flange width of +10% and 10mm rib thickness respectively are having the best flutter frequencies. The wing with above features is further optimised by keeping weight as a constraint by introducing circular and triangular cut-outs section. Flutter frequency for without cut-out, circular cut-out and triangular cut-out are 77.84 Hz, 78.27Hz and 78.43Hz respectively. Hence it is concluded that ribs with triangular cut-outs can be able to reach maximum flutter frequency.\",\"PeriodicalId\":14391,\"journal\":{\"name\":\"International Journal of Vehicle Structures and Systems\",\"volume\":\"13 1\",\"pages\":\"\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2023-04-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"International Journal of Vehicle Structures and Systems\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.4273/ijvss.15.1.14\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"Engineering\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"International Journal of Vehicle Structures and Systems","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.4273/ijvss.15.1.14","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"Engineering","Score":null,"Total":0}
Design and Optimization of Wing Internal Structure to Study the Flutter Frequency of Aircraft Wing
The field of aviation has reached a lot of milestones in the 19th and early 20th century, but the supersonic commercial flights are still a nightmare in 21st century. The major obstacle to reach this milestone is the effect of flutter, which is an aeroelastic phenomenon. It is very important to understand the effect of flutter to reduce it. In this paper effect of flutter is studied by varying the wing internal structures. A scaled down model of the AGARD 445.6 wing having 65A004 aerofoil is designed using Catia V5, for which the experimental data is available for validation. Grid independence study is carried out to obtain more reliable mesh quality. Since flutter is a transient phenomenon time-step independence study is carried out for the time steps of, 0.005s, 0.0025s and 0.00125s. Since there is no difference between the flutter frequency readings for 0.0025 seconds and 0.00125 seconds, 0.0025 seconds is chosen to reduce the computation time. The baseline case is validated with an experimental data available and an error of 0.2-5.32% is observed. Aircraft wing is mainly made out of aluminium alloys. Hence a suitable aluminium alloy is selected by comparing the flutter frequencies. To choose a suitable material, three materials each from wood, alloys and composite are considered i.e., mahogany, aluminium alloy 7075 T6 and Aluminium Metal Matrix Composite (AMC) which are widely used in the Aviation industry. AMC is considered on the basis of frequency charts whose flutter frequency is 30Hz. In this paper in order to supress the flutter we have introduced optimization of ribs and spars in the wing. Variation in the number of ribs, flange width and rib thickness are considered individually. Wing configuration with 10 ribs, flange width of +10% and 10mm rib thickness respectively are having the best flutter frequencies. The wing with above features is further optimised by keeping weight as a constraint by introducing circular and triangular cut-outs section. Flutter frequency for without cut-out, circular cut-out and triangular cut-out are 77.84 Hz, 78.27Hz and 78.43Hz respectively. Hence it is concluded that ribs with triangular cut-outs can be able to reach maximum flutter frequency.
期刊介绍:
The International Journal of Vehicle Structures and Systems (IJVSS) is a quarterly journal and is published by MechAero Foundation for Technical Research and Education Excellence (MAFTREE), based in Chennai, India. MAFTREE is engaged in promoting the advancement of technical research and education in the field of mechanical, aerospace, automotive and its related branches of engineering, science, and technology. IJVSS disseminates high quality original research and review papers, case studies, technical notes and book reviews. All published papers in this journal will have undergone rigorous peer review. IJVSS was founded in 2009. IJVSS is available in Print (ISSN 0975-3060) and Online (ISSN 0975-3540) versions. The prime focus of the IJVSS is given to the subjects of modelling, analysis, design, simulation, optimization and testing of structures and systems of the following: 1. Automotive vehicle including scooter, auto, car, motor sport and racing vehicles, 2. Truck, trailer and heavy vehicles for road transport, 3. Rail, bus, tram, emerging transit and hybrid vehicle, 4. Terrain vehicle, armoured vehicle, construction vehicle and Unmanned Ground Vehicle, 5. Aircraft, launch vehicle, missile, airship, spacecraft, space exploration vehicle, 6. Unmanned Aerial Vehicle, Micro Aerial Vehicle, 7. Marine vehicle, ship and yachts and under water vehicles.