sae 1999-01-5640 development of wing structural weight equation for active aeroelastic wing technology

1、1999-01-5640Development of Wing Structural Weight Equation for Active Aeroelastic Wing TechnologyP. Scott Zink and Dimitri N. MavrisGeorgia Institute of Technology Peter M. FlickWright-Patterson Air Force Base Michael

2、H. LoveLockheed Martin Tactical Aircraft Systems1999 World Aviation Conference October 19-21, 1999 San Francisco, CAFor permission to copy or republish, contact the American Institute of Aeronautics and Astronautics or S

3、AE International.JB J- The Engineering Society For Advancing Mobility Land Sea Air and Space® INTERNATIONALSAE International 400 Commonwealth Drive Warrendale, PA 15096-0001 U.S.A.American Institute of Aeronautics

4、 and Astronautics 370 L'Enfant Promenade, S.W. Washington, D.C. 20024Figure 6 is a plot of wing weight versus aspect ratio. One clearly sees the significant weight savings that AAW technology can provide particular

5、ly for the high aspect ratio, high thickness ratio cases. In addition, for the same weight AAW technology would allow the use of a higher aspect ratio wing, which agrees with the initial AAW claim that for the same am

6、ount of wing weight a better aerody- namically performing wing can be used.Figure 7, which is a plot of weight versus thickness ratio, shows once again that maximum weight savings due to AAW technology occurs for the h

7、igher weight wings. This conclusion is similar to one made by Yurkovich in Reference [5]. In addition, one observes the significant impact that thickness ratio has on weight as weight decreases dramatically with incr

8、easing thickness ratio. It is important to note, however, that the weight equations do not consider the impact of drag, so it is reasonable to expect that at some higher thickness ratio, the weight would begin to rise

9、. Also, one can begin to see why a quadratic model was a poor predictor of the exact relationship between weight and geometry, particularly for the conventional approach, as weight grows very quickly with decreasing

10、thickness ratio.In the plot of weight versus taper ratio (Figure 8), one observes that taper ratio does not have nearly the impact on weight as do the other two geometry parameters. There is, though, the consistent tr

11、end of increasing weight with increasing taper ratio, which makes sense as more wing area (and thus more load) is shifted outboard as the taper ratio increases.VALIDATION - One final test of RSE fit is a validation tes

12、t, where the wing weight is evaluated at a number of random points in the design space and compared to its value as predicted by the RSE. The conventional approach RSE is validated in Table 4 by evaluating the wing we

13、ight for four cases where each case corresponds to a random point in the wing geometry design space (Table 2). The weight from each case is then compared to that predicted by the RSE and a percent difference calculat

14、ed.CONCLUSIONSA process has been implemented by which wing weight equations are developed for a lightweight composite fighter considering both AAW technology and conventional control technology. For future design

15、studies of advanced fighters that employ AAW technology, these equations could then be used to complement the historically based equations that are currently residing in standard synthesis/sizing codes. T

16、he study demonstrated the viability and effectiveness of several key elements of the wing weight generation process. These include theEI21IC1N8 EI21IC1N8z一二quoM quoM U2S U2S xs xs 置MTable 4. Validation ResultsCase #

17、 WeightConv( Actual) WeightConv(RSE) Error1 315.60 324.46 -2.81 %2 422.40 408.70 3.24%3 333.40 356.21 -6.84 %4 364.80 370.24 -1.49%(£二gQM gQM US US >/Figure 6. Wing Weight vs. Aspect Ratio工 2343658442444.6 4龍Aspe

18、ct Ratiooxoai)J5aoiu.oc5a 儂o.o5Thickiwss RatioFigure 7. Wing Weight vs. Thickness RatioTaper Ratio = 0.3ConventionalAR =5C'uinentHMiulFigure 8. Wing Weight vs. Taper RatioXDxf/ XDxf/ Eixuw EixuwTable 4 shows that the

19、 largest difference between the actual and RSE predicted weights is just under 7%, indicating that the RSE is a good predictor of the exact relationship between wing weight and wing geometry for the conventional appr