1、N79-17801DELTA METHOD, AN EMPIRICALDRAG BUILDUP TECHNIQUER.C. Feagin, et alLockheed - California CompanyBurbank, CaliforniaDecember 1978Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-111Provided by IHSNot for ResaleNo reproduction or networking perm
2、itted without license from IHS-,-,-lk * _ _i_ _:_._ _/_ _i_“ ,CNASA CONTRACTOR REPORT 151971 _(ASA-CR-151971) DELTA METROD, AN EMPIRICAL N_DR_G BUILDUP TECHNIQUE Fina.l Report, 1 Mar.- 31 Dec. 1978 (Lockheed-Callfornla Co.,Burbank.) 177 p HC A09/MF A01 CSCI 01A Unclas _G3/02 16136DELTA METHOD, AN EM
3、PIRICALDRAG BUILDUP TECHNIQUE- L!Richard C. Feagin and William D. Morrison, Jr.LOCKHEED-CALl FORNIA COMPANYBURBANK, CALl FORNIA 91520rContract NAS 2-8612, Mod. 6December 1978!N6SANational Aeronautics andSpace AdministrationAmes Research CenterMoffett Field, CA 94035,-_01_1_NATIONAL TECHNICAL -INFORM
4、ATION SERVICE J_U.S.D(/_tllNt Of C0U_RC_ rSPRIN_ELD,VA.72161 j-_:-_._:l:_u_. _,_:._w-._i _, _:Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-I!1Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA CO
5、NTRACTOR REPORT 151971DELTA METHOD, AN EMPIRICALDRAG BUILDUP TECHNIQUERichard C. Feagin and William D. Morrison, Jr.LOCKHEED-CALl FORNIA COMPANYBURBANK, CALIFORNIA 91520Contract NAS 2-8612, Mod. 6December 1978N/LSANational Aeronautics andSpace AdministrationAmes Research CenterMoffett Field, CA 9403
6、5Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-1 11Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-i. REPORT NO.NASA CR 151971_. YITCE AN_sUBTITLE2. GOVERNMEi_Ir ACCESSION NO.DELTA METHOD, AN EMPIRI
7、CAL DRAG BUILDUP TECHNIQUE7. AUTHOR(S)Richard C. Feagin N STATEMENT(OF THIS PAGE) 21. NO. OF PAG(_$ 22. PRICE*i ,i IProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-IIIProvided by IHSNot for ResaleNo reproduction or networking permitted without licens
8、e from IHS-,-,-TABLE OF CONTENTSSection1i.i1.21.31.3.11.3.21.3.31.3.41.41.51.61.71.82.2.12.22.32.433.13.1.13.1.23.23.33.3 .i3.3.2PageLIST OF FIGURES LIST OF TABLES SUMMARY . 1INTRODUCTION 2LIST OF SYMBOLS 4DRAG PREDICTION PROCEDURE 7Design Lift Coefficient and Mach Number 9Skln Friction (CDF) . i0Co
9、mpressibilityDrag( CDc) . 13Wing compressibility drag (_CDcWING) 13Fuselage compressibility drag (_CDcFUS) 13Interference drag (_CDcINT) 14Total compressibility drag (_CDc) 14Miscellaneous Drag ( CD) . 15Induced Drag 15Wing Pressure Drag (CDp) 15Total Aircraft Drag (CD) 16Buffet Onset (CLB.O.) 16DAT
10、A REDUCTION TECHNIQUE . 52Design Lift Coefficient and Mach Number 52Drag Divergence Mach Number Drag Breakdown .Component Compressibility Drag DATA CORRELATION CLDE S and MDE S CL design .M design .Friction Drag Correction Factor Compressibility Drag . 5353. 56. 58. 6060. 626363Compressibility drag
11、due to wing volume . 64Compressibility drag due to fuselage volume . 64iiiProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Section3.3.33.3.43.444.14.24.34.3.14.3.24.3.34.3.44.44.54.64.7AppendixATABLEOFCONTENTS (Continued)Wing body interference drag Wi
12、ng pressure drag due to lift .Buffet Onset EXAMPLE AIRCRAFT DRAG BUILDUP Design Lift Coefficient and Mach Number Friction Drag .Compressibility Drag .Fuselage compressibility drag .Wing compressibility drag .Wing/body interference drag Total compressibility drag .Total Minimum Drag Page6565661351351
13、37140140141142142143Wing Pressure Drag 144Total Configuration Polar 146Buffet Onset . 147FORM FACTOR GENERATION 160ivProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-LIST OF FIGURESFigurei2345678910ii1213141516171819202122232425262728PageDesign lift c
14、oefficient .Two-dimensional drag divergence Mach number,supersonic airfoil sections .Drag divergent Mach number, subsonic airfoil sections MD2LD correction parameters .Variation of flat plate incompressible turbulent skinfriction coefficient with Reynolds number . . Body form factor Wing section for
15、m factors Compressibility correction to skin friction coefficient . . .Friction drag correction parameter .Subsonic wing compressibility drag .Supersonic wing compressibility drag Suggested method of fuselage geometry parameter selection . .Subsonic fuselage compressibility drag .Supersonic fuselage
16、 compressibility drag Wing/body zero lift interference drag Subsonic wing pressure drag, AR (t/)1/3 0.5 .Subsonic wing pressure drag, AR (t/i)i/3 1.0 .i re d g AR (t/)1/3 2.0 .Subsonic w ng pressu ra , :iSubsonic wing pressure drag, AR (t/) 13 4.0 .Subsonic wing pressure drag, AR (t/.)i/3 = 6.0 ./Su
17、personic wing pressure drag, AR (t/c)l3 = 0.8 Supersonic wing pressure drag, AR (t/c)i/3 = 1.00 . .Supersonic wing pressure drag, AR (t/c)I/3 - 1.20 Supersonic wing pressure drag, AR (t/c)I/3 - 1.40 Supersonic wing pressure drag, AR (t/c)i/3 = 1.60 Supersonic wing pressure drag, AR (t/c)i/3 - 1.80 S
18、upersonic wing pressure drag, AR (t/c)i/3“ = 2.0 Buffet onset 18192021222425262728293031323334363840424445464748495051vProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Figure293O3132333435363738394O4142434445464748495O5152535455565758LIST OF FIGURES (
19、Continued)PageDrag breakdown procedure 57CLDE s correlation, subsonic aircraft . 68CLDES correlation, supersonic aircraft 67MD2_D data correlation, subsonic configurations 69MD2_D data correlation, conventional and supersonic airfoilsections . 72Friction drag correction parameter correlation . 74Sub
20、sonic win_ compressibility drag correlation i 75Supersonic wing compressibility drag correlation 77Subsonic fuselage compressibility drag correlation . 81Supersonic fuselage compressibility drag correlation 83Wing/body interference drag correlation . 87Subsonic ACDp correlation, _C L - -0.30 . 90Sub
21、sonic ACDp correlation, _C L = -0.20 . 92Subsonic ACDp correlation, _ - -0.i0 94Subsonic _CDp correlatlon, _C L - -0.05 . 96Subsonic _CDp correlation, _ - 0 . 98Subsonic ACDp correlatlon, A_ - +0.05 . 100Subsonic ACDp correlatlon, A_ -+0.10 . 102Subsonic ACDp correlatlon,_C L - +0.20 . 104Subsonic A
22、CDp correlation, AC L - +0.30 . 106_upersonlc wing pressure drag correlation, _C L - -0.30 . . . 108Supersonic wing pressure drag correlation, _C L - -0.20 . . . iiiSupersonic wing pressure drag correlation, AC L - -0.I0 . . . 114Supersonic wing pressure drag correlation, _C L - -0.05 . . . 117Super
23、sonic wing pressure drag correlatlon, AC L = 0 . 120Supersonic wing pressure drag correlation, _C L - +0.05 . . . 123Supersonic wing pressure drag correlation, _C L - +0.10 . . . 126Supersonic wing pressure drag correlation, _C L - +0.20 . . . 129Supersonic wing pressure drag correlation, _C L - +0.
24、30 . . . 131Buffet onset correlation 132vl_-E . . _ Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-Figure596O61626364656667686970717273LIST OF FIGURES (Continued)PageSubsonic compressibility drag comparison 149Supersonic compressibility drag compari
25、son. 150Drag-due-to-lift comparison, A-4F 151Drag-due-to-lift comparison, RA-SC . 152Drag-due-to-lift comparison, T-2B and KA-3B 153Drag-due-to-lift comparison, A-7A . 154Drag-due-to-llft comparison, F-5A . 155Drag-due-to-lift comparison, F-4E 156Drag polar comparison, A-4F 157Drag polar comparison,
26、 RA-SC 158Buffet onset comparison 159Variation of minimum CDBoDJith_ body fineness ratio . 161Body form factor comparison 162Ratio of minimum drag to theoretical skin friction dragfor conventional, state of the art, and advanced airfoilsections 163Wing section form factor correlation 164viiProvided
27、by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TableI234LIST OF TABLESBasic Geometry .Correlation Parameters . . . . . . .Design Lift Coefficient Calculation Design Mach Number Calculation .Page5961136138viiiProvided by IHSNot for ResaleNo reproduction or ne
28、tworking permitted without license from IHS-,-,-DELTAMETHOD,ANEMPIRICALDRAGBUILDUP TECHNIQUERichard C. Feagin and William D. Morrison Jr.Lockheed-California CompanyBurbank, California 91520SUMMARYThe Lockheed-Callfornia Company, under NASA Ames Contract No. NAS2-8612,Mod 6, has applied empirical dra
29、g correlation techniques to 19 subsonic andsupersonic military aircraft and 15 advanced or supercritical airfoil conceptsto develop an empirical drag estimation technique which can be applied infuture design activities. The resulting method is presented in this report.The use of the technique provid
30、es a capability of estimating the total con-figuration drag polar near the cruise lift coefficient (Design CL 0.30)and a speed range from Mach 0.40 to approximately Mach 2.0. Included alsois the capability of predicting the subsonic off-deslgn performance ofadvanced or supercritical airfoil sections
31、. Buffet onset may also be esti-mated. The method can be applied to wind tunnel models as well as to fullscale configurations. The technique has been converted into a computercode which is compatible with the NASA Ames computer facilities. Theprogram, “Empirical Drag Technique (EDET)“, is presented
32、in reference 2.Results obtained using this method to predict known aircraft characteristicsare good and agreement can be obtained within a degree of accuracy Judgedto be sufficient for the initial processes of preliminary design.Provided by IHSNot for ResaleNo reproduction or networking permitted wi
33、thout license from IHS-,-,-INTRODUCTIONIn a conceptual and preliminary design atmosphere, it is desirableto employ quick methods of configuration evaluation in the first steptowards configuration selection, and necessary when there are numerousconfigurations under consideration. The emperlca approac
34、h of analysisis to use information already known about existing aircraft to predictthe characteristics of future designs. Such an approach is adopted forthis study.The Lockheed-Californla Company, under NASA Ames Centract No. NAS2-8612,Mod 6, has applied the empirical total drag technique of referer
35、_ce 1 on19 supersonic and subsonic military aircraft and 15 advanced or super-critical airfoil concepts to develop an empirical drag estimation techniquewhich can be applied in future preliminary design activities. Correlatedestimations of design llft coefficient and Mach number, compressibility and
36、pressure drag, and buffet onset were generated, and the resulting methodis presented in this report.This method can be used to estimate the total configuration drag polarwithin a CL range of 0.0 to 0.60 or buffet onset and a _peed ravage of0.20 fthickness, camber, aspect ratio, sweep, and AM. These
37、curves are restricte3to wings of effective thickness ratio less than 0.065 and aspect ratios lessthan f_ve (5) as these were the outer bounds of the data from which the cor-relation was derived. The reader should note the change in correlation par-ameter between subsonic and supersonic configuration
38、s. The data correlationfor figure Ii is given by figure 36 of Section 2.1.3.2 Fuselage compressibility drag _CDcFUS._).- To estimate properly thecompressibility drag of a fuselage, the user of this technique begins with apreliminary estimation of the area distribution. Here, in contrast to thefricti
39、on calculation, it is extremely important that this distribution no_tinclude the inlet capture area. The cross-sectional areas of horizontal andvertical tail surfaces should be included, however, in order to remain con-sistent with the methods used in developing the following data. The contri-bution
40、 of the empennage to the overall compressibility drag is usually smallwhen compared to the whole but still should not be overlooked.13Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-From the area distribution the user estimates the total length (_),m
41、aximum cross-sectlonal area (S_), and base area (Sb). These parameters areconfiguration oriented and large variations can be expected from aircraft toaircraft. A consistent method of determining their values is, therefore,necessary to make this drag estimation procedure meaningful. Figure 12 pre-sen
42、ts the method used in this study for fuselage geometry estimation. Thismethod should be followed as closely as possible to maintain consistencythroughout the drag computation. Area progression curves for the majority ofthe study aircraft are presented in reference 33.Subsonic fuselage compressibilit
43、y drag is presented in figure 13 as afunction of the geometry parameters and Mach number. It should be noted thatfuselage and interference drag computations are based on the free stream Machnumber, while all other drag items are based on the design Mach and arecorrelated against _M. The value of CDv
44、 obtained from figure 13 is based onmaximum fuselage area (Sw) and is converted to the reference wing area bythe relationship._CDcFUS . CD= S(_)(ll)Figure 14 gives supersonic fuselage compressibility drag as a functionof body fineness ratio, base to maximum area ratio, and Mach number. Equa-tion (ii
45、) must be used to convert the value of CD_ obtained from this figureto the correct area relationship also. The data correlations which producedfigures 13 and 14 are presented in Section 3, figures 37 and 38.1.3.3 Interference drag _ICDcINT). - Wing/fuselage interference drag, asderived for this meth
46、od, is presented in figure 15 as a function of bodydiameter to wing span ratio, taper ratio, and wing sweep. The assumptionis made that interference drag is zero below Mach number equal to 1.0. Thecorrelation of data which produced this relationship is shown on figure 39.1.3.4 Total compresslbillt_
47、drag (Z_CDc)-.I - The values of _CDcWING , _CDcFUS,and _CDcINT are now combined to produce the total configuration compressibilitydrag by use of Equation (5). The resulting values, when added to the previously14Provided by IHSNot for ResaleNo reproduction or networking permitted without license from
48、 IHS-,-,-computed level of friction drag, will produce a configuration drag level whichis independent of llft throughout the desired Math range.1.4 Misce!laneous Drag (_CD)A11owance is made within the coding of this procedure for the additionof a miscellaneous drag level (_C D) so that the effects of a configurationchange or an external store may be included. Such drag leve
