1、22/3“ 3 copy.: RIM L56G12,-.+,. .-RESEARCH MEMORANDUMADDITIONAL RESULTS OF AN INVESTIGATIONAT “TRANSONIC SPEEDS TO DETERMINE THE EFFECTS OF AHEATED PROPULSIVE JET ON TRE DRAG CHARACTERISTICSOF A SERIES OF RELATED AFTERBODIESBY Wverly Z. Henry, Jr., and Maurice s. CakLangley Aeronautical LaboratoryLa
2、ngley Field, Va.cLAs31FmJmxuKm-rm !lMOrlal Wntalns !mOrua this reduction was insignif-icant for the low-drag bodies but became significant for bodies ofblunt shape. Increasing stremMach nunibercaused no change in jeteffects for the low-bag bodies, whereas for the more blunt bodies therewas a slight
3、trend toward increased jet effects.INTRODUCTIONA -previousinvestigation conducted in the Langley 8-foot transonictunnel (ref. 1) to evaluate some of the effects of a sonic propulsive.jet as influencedby changes in afterbody geometry indicated the desir-ability of studies extending this research to b
4、odies with lower boattailangle and small jet-to-base diameter ratios. The results presented*heein are therefore a continuation of the work reported in reference 1Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2 NACA RM L56cH.2and were obtained in an
5、 identicalmsmner. The investigationwas con-ducted at an angle of attadk of 0 through the Mach number remge from a0.80 to 1.10, and at each point the jet temperature and -pressureratiowere varied. iPresented in this report are the basic data obtained from the inves-tigation. The data are presented wi
6、th limited analysis in order to expe-dite their availabilityto those concernedwith jet-exit-afterbodv.design.ACDPt1MCpRtdPPYSYMBOISarea1yzdrag coefficient, Gtotal pressurelengthMach numberP - Pmpressure coefficient,%Reynolds number, based on body lengthtotal temperature,diameterstatic pressuremmic p
7、ressure,afterbody boattail; PM2angle, degratio of specific heatsSubscripts:A afterbodyb base.bProvided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM L512 3J jetw free streamB boattail1 localmax model maxbumAPPARATUS AND mmsWind TunnelThis investigat
8、ionwas conducted in the Langley 8-foot transonictunnel which has a dodecagonal slotted test section that permittedcontinuous testing up to a Mach nurr.iberof approxin%tely 1.10 for thesemodels. The tunnel is vented to the atmosphere through an air exchangetower which permits the exhausting of cotius
9、tion gases from the modelinto the strean with no detrimental effects on the characteristics ofthe stream. Details of the test section are presented in reference 2Aerodynamic characteristicsof the airstresm are given in reference 3wherein it is shown that the maximum deviation from the indicated free
10、-stresm Mach number is *0.003.ModelsThe models used in the investigationwere bodies of revolution,the rear portions of which were removed to provide an exit for the jet.These bodies had fineness ratios from 10.O to 10.6. A single forebody(see table I) was used throughout the investigation and the mo
11、del designallowed the ready interchsmge of afterbodies of various geometric shapes.The models were mounted in the tunnel by means of two swpport struts.These support struts, with a chord of l_l.25inches and an I!7ACA65-010 air-foil section measured parallel to the airstresm, were placed so that thel
12、eading edge intersected the bcdy at a point 21.7 inches from the noseand were swept back 45. A sketch of the general arrangement of themodel in the tunnel is shown in figure 1. For all tests the nose of themodel was located inches downstream of the slot origin.Presented in table II is the equation u
13、tilized to”define the exter-nal shapes of the afterbodies investigated. Also shown are the design.points used to assign values to the equation. The ordinates from whichthe body shapes were constructed are given in table I. Drawings of theafterbody shapes are shown in figure 2. The models were instru
14、mentedw15.70Afterbcdy XIII, d! -1,240, dj/dmx=0.248, dj/c$)=O.336.Mdj,Q#$?-.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NACA RM L76G12-.06.04.020:02.04.020+221Jet eswe rdb, PtjM Jei e=s-swe ratia, PtJ/Pm(a)Afterbody I. P = 16, # = %=070.248, db “
15、 max. Figure 5.- Variation of base, boattail, and total afterbody pressue-dragcoefficient with jet pressure ratio for different values of jet tem-perature and stream F CD,A CDJ? ,bcold o AJet pressure ratio, pt,j/Pco(e)Afterbody XII. = 16,Figure 5.-25=(O 2 4 6 8 10 12Jet pressure ratio, Pt,jPa3+_ .0
16、.248, = 0.38!3.Inax dbContinued.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-26tjF ,Q CD,pCold O ANACA FM L%G12Jet pressure ratio, Pt,j/Rm,Jet prewre ratio, Pt,j /FWI(e) Concluded.Figure 5.- Continued.$V .Provided by IHSNot for ResaleNo reproducti
17、on or networking permitted without license from IHS-,-,-NACA FM L56G12.Vn+.,27Jet pressure ratio, Pt,j)b(f)Afterbody XIII. =.16,Jet pressure ratio, pt,jRO. dj=0.248, $ = 0.336.Figured= ab5=- Continued.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-2
18、8 NACA RM L56G12Jet pessure ratio, Pt,jBSl Jet pessure ratio, Pt,jP(f) Concluded.Figure 7.- Continued.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-CJ NACA RM L56G12 29u. .cD/Io3Jet pressure ratio, pt,j /PaI Jet Prwiure ratio, Pt,j/(g) Afterbody XIV. P .0, . 0.331, .0.351.d-l?igme 5.- Concluded.NACA - Langley Field, Va.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
