ImageVerifierCode 换一换
格式:PDF , 页数:15 ,大小:662.20KB ,
资源ID:836499      下载积分:10000 积分
快捷下载
登录下载
邮箱/手机:
温馨提示:
如需开发票,请勿充值!快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。
如填写123,账号就是123,密码也是123。
特别说明:
请自助下载,系统不会自动发送文件的哦; 如果您已付费,想二次下载,请登录后访问:我的下载记录
支付方式: 支付宝扫码支付 微信扫码支付   
注意:如需开发票,请勿充值!
验证码:   换一换

加入VIP,免费下载
 

温馨提示:由于个人手机设置不同,如果发现不能下载,请复制以下地址【http://www.mydoc123.com/d-836499.html】到电脑端继续下载(重复下载不扣费)。

已注册用户请登录:
账号:
密码:
验证码:   换一换
  忘记密码?
三方登录: 微信登录  

下载须知

1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。
2: 试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。
3: 文件的所有权益归上传用户所有。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 本站仅提供交流平台,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。

版权提示 | 免责声明

本文(NASA NACA-TR-658-1939 Tests of two full-scale propellers with different pitch distributions at blade angles up to 60 degrees《在桨叶角为60时 有不同倾斜分布的两个全比例螺旋桨的试验》.pdf)为本站会员(sumcourage256)主动上传,麦多课文库仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知麦多课文库(发送邮件至master@mydoc123.com或直接QQ联系客服),我们立即给予删除!

NASA NACA-TR-658-1939 Tests of two full-scale propellers with different pitch distributions at blade angles up to 60 degrees《在桨叶角为60时 有不同倾斜分布的两个全比例螺旋桨的试验》.pdf

1、REPORT No. 658TESTS OF TWO FULL-SCALE PROPELLERS WITH DIFFERENT PITCH DISTRIBUTIONS,AT BLADE ANGLES UP TO 60By DAVID BIRM.iM and EDTIN P. HARTMANSUMMARYho S-blade 10oot propellers were operated in jiontoj a liquid-cooled en”nenacelle. Tite propellers diferedonly in p“tch distribution; one had normal

2、 distribution(nearly constant p“tchfor a blade angle of 16 at 0.76radius), and the other had the pitch of the tip ectionsdecreasedwith respect to that for the shank sections (bladeangle of 36 for nearly constant pitch distrz”butior,). Pro-peller bladeangles at 0.75Rjrona 16 to 60, correspondingto de

3、sign speeds up to 600 miles per hour, were investi-gated.The results indicated that the propultice eficieney at ablade angle of 60 was about 9 percent less tha:nthe mati-muna aalue of 86 percent, which occurred at a blade angleof aboui 30. Tle ejiciency at a blade angle of 60 wasincreased about 7 pe

4、rcent by correctingfor the eect of asp”nner and, at a blade angle of 30, about $3percent.T7Mpeak efitiencieg for the propeller huuing the uxzshed-out pitch distm”butionwere slightly lesg than for the normalpropeller but the take-of ejhiency was generally higher.INTRODUCTIONTests of full-scale propek

5、-s made at the X. . only the results for the two extreme pitch dia-tributiona tith the liquid-cooled engine nacelle aretherefore reported.In tiew of the fact that propeller spinners are verybeneficial for high-speed airplanes equipped withliquid-cooled engine nacehs, the results of the testaof the p

6、ropelk with the standard pitch distributionat a blade angle of 15 are ako given for the spinnercondition.827Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-328 REPORT NQ. 656-NATIONAL. ADVISORY CCWMITTEEFQR AERONAUTICSAPPARATUS AND METHODSThe propell

7、er-research tunnel has been modifiedsince the description of reference 2 was written to theextent of installing an electric.motor to drive the tunnelpropeller and. of replacing te balance. with a moremodern one capable of R radfusto the tip; r, stationmdtus;b, ssct!onchord; b,swtlon thfck-nw II, gso

8、rnetrlopitch.and a comparison of the pitch distributions is given infigure 5.The method of testing in the propeller-research tun-nel consists in maintaining the propeller speed constantand increasing the tunne speed in steps up to thomaxurn value of 115 miles per hour. Higher valuesof lnD are obtain

9、ed by reducing the engine speeduntil zero thrust is reached. The tests were run at tipspeeds of 525 feet per second and k to avoid com-plications arising from compressibility. The standardinitial testing propeller speed of 1,000 r. p. m. couldnot be maintained for the higher blade-angle settingsProv

10、ided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TWO FULL-SCALE PROPELLERS WITH - - - -.1JIJflMlffiN1 YlUtl JJMLIU.B lJ1lW.Nt3 329owing to the limitation of engine power. The follow-ing schedule was adhered h:Propeller apeeti for tunnelspeed below 116 mil

11、es per hourBladeangle(de%) lnKhim,e,d mdedeayle ,MCr(yymg apecd15 1,000 40 70020 1,000 45 70025 8CK) 50 65020 800 55 60035 800 60 560For _linD values higher than can be obtained fromthe foregoing schedule, the approximate t-t propeIIerspeed may be computed from t,herelationr. p. m. =Fydwhere K= 1,00

12、0 for T7=115 miles per hour and D= 10feet.An analysis of results from tests with the spinner forpropeller blade angles of 15,25, and 35 indicated thatthe effect of the spinner could be trardated into a dragvalue independent of the blade angle (5.5 pounds at100 miIes per hour). The rewdts without the

13、 spinnerwere consequently corrected for the effect of the spinnerby the formulaAC,= O.OO1O75(V/nD)2instead of making additional tests with the spinner.Any erroreincidental to this process are considered to bewithin the experimental error. This formtia appliesonly to the conditions of the present tes

14、ts.The spinner was regarded as a part of the body; thereduction in drag of 5.5 pounds at 100 miks per hourwas therefore primarily due to enclosing the hubportions of the propeller.RESULTS AND DISCUSSIONThe results are reduced to the usual coefficients ofthrust., power, and propulsive ef6ciency defin

15、ed aseffective thrust TADc= D, Dengine povrer0.= ,Dc. vV=c. mwhereT, tension in propeller shaft, pounds.AD, change in body drag due to slipstream, pounds.p,mass density of the air, slugs per cubic foot.nj propeller speed, r. p. s.D, propeer chneter, feet.l“, air speed, feet per second.Charts for sel

16、ecting or designing propellers are givenin the form of C, against and V/nD,Lines of constant thrust coefficient have been super-posed on the power-coedlicient curves to facilitatethrust computations at alI air speeds for tied-pitch andcontrollable propellers. For an outline of the methods,see refere

17、nce 3.The test results are given in the form of charts infigures 6 to 17. These results have aIso been tabulatedPr/RFmmE t +0 .2 .4 .8 .8 LO /.2 L4 1.6 L8 2.0 EL? 2.4 2,6 2,8 3.0 3.2 3,4 38 3.8 4,o 4.2 4,4 4.6V/nDFmrmBL5.-ThrusGooeflMent ctmes for propeller 6SS9 wfth nplnnw. CNwCJlProvided by IHSNot

18、 for ResaleNo reproduction or networking permitted without license from IHS-,-,-coCua.68.64.60.56.52.48.44.40.36G.32,28.24,20.16.12.08.040 ridz,oFmuBB 16.-PowoLmt cxmremfor propaks LWE?-9wltb nne8.Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-TWO F

19、ULL-SCALE PROPELLERS WITH DIFFERENT PITCH DISTRIBUTIONS 3375.0.8v.4 40uwvG2.0/.(7Q /.o .20 3!0 4.0 50 beyond thisvalue there is a small loss. The reasons for this condi-tion are apparent in figures 19.and 20, wherein a comp-arison is made of the propeller characteristics for threeeffective pitch-dia

20、meter ratios for zero thrust. It maybe noted that propeller 5868X2 does not stall so soonwith increasing angle of attack (decreasing V/nD) asdoes propeller 5868-9, which accounts for the gain ineficiency. The efficiency ccmrputed for the take-offcriterion is taken at a value of_V/nD of one-fourth th

21、atfor hh speed. l?ropeIIer 5868-X, consequently has ahigher take-off efficiency for conditions where theV/nD for stall coinoides with the takeoff criterionV/nD wd has a lower efficiency when the vahws do notcoincide. The delayed and abrupt stalling character-istic noted for propeller 5868-X2 is evid

22、entiy due tothe fact that more of the bade elements stall at thesame time than for propeller 58689.Limitations and application of the test data,In viewof the fact that the present tests were run at relativelylow tip and twmel speeds, the effect of comprcesibility,which enters the problem at higher s

23、peeds, should notbe fcygotten. It is pointed out in rcferencc 5 thatcorrections to the propeller chara.cterist.icsfor tho take-off condition shouId be made for tip spec_dsabove about0.5 the speed of sound.-Eadier tests (reference 6) had indicated that noappreciable loss in efficiency was evident at

24、tip speedsbelow about 0.9 the speed of sound for the high-speedcondimon. Later evidence shows that this value appliesonly to forward speeds up to 200 or 300 miles per hour.Figure 21 is a plot of the true speeds of each propellersection for a true tip speed of 1,000 feet per second(approximately 0.9

25、the speed of sound at sea level) nndfor dithrent flight speeds. The curve of the sectionspeeds corresponding h the compressibility stall wassomputed from airfoil data given in references 7 and 8md from other high-speed airfoil data not published.An arbitrary correction for thee-dimensional flow wasD

26、ade for the tip sections to bring the airfoil and tho?ropach ropellw seciknI I I I IJ? ffor dferenf fligh speeds-Computed secfion speed Of fhecompressibility sfull for see-level flighf700 II 1 1)m Ctark Y-f Hp;e v/5& . / fm / / +, /e /q 400 /GMO . / /3 1/ /$ 300 f /J 300 /$ / a, Arbitrary correcfimf

27、or ihree-dimensiona/flow of fhe fip200/m/ao,o .2 .4 .6 .8 Jor/RFmrmx 21.Curve9 showing true W* of propsller 6wtforu for a tfp * of MOOf. p. m and dlffarent flfght spealx aho comrmtadwtkm SW* at the eompres4-blllty stall.CONCLUSIONSThe propulsive d3hiency at a blade angle of 60 vm.sabout 9 percent Im

28、s than the maximum value of 86percent, which occsurredat a blade angle of about 30.The efficiency at a blade angIe of 60 was incrmeedabout 7 peroent by correcting for the effect of a spinnerand at a blade angle of 30, about 3 percent.An attempt to improve the propulsive efficiency ofpropellers set a

29、t high blade angles by reducing thegeometric pitch of the tip sections with respect to theshank sections (namely, increasing the blade gle fornearly oonstant pitch distribution from 15 to 35)resulted in a small loss in the bigh+peed efficiency and again in the take-off efficiency for low blade angle

30、s.The blade-angle range covered in this report isapplicable to flight conditions up to about 500 milesper hour at sea level and about 425 miles per hour at35,OOOfeet, provided that comprwsibility effeots at theblade tips and shanks do not become critical.LANGLEY MEMORIAL AERONAUTICAL LABORATORY,NATI

31、ONAL JbVISORY COMMImnEFOR AERONAUTICS,LANGLEY FIELD, VA., April IJ, 1838.,-1“i.rue&ee& of &OLJlkr iechbk I1- Cmnpuied sechon kped fII .compressibifify sfuli t+o .2 .4 .6 .8 I.orjlfFIOUESZ2.-Bladeaectlon aPeaIs owraspa!dfng to hkh+-p=d opsratfon at “ bkxleangle, and cmnpated serdfrm crItfml spead9 fo

32、z dh.lamnt althxdw. ProLarSSS-9 with apInner.1.2.3.4.6.6.7.8.REFERENCESLesley, E. P., and Reid, Elliott G.: Tests of Five MetalModel Propellers with Varioue Pitch Distributions in a FreeWiid Stream and in Combination with a Model VE-7FuasIage. T. R. No. 326, N. A. C.& 1929.Weiuk, Fred E., and Wood,

33、Donald H.: The Twenty-FootPropeller Research TunneI of the National Advisory Clmm-mittee for Aeronautic. T. R. No. 800, N. A. C. A., 192%Biermann, David, and Hartman, Edwin P.: Tests of FiveFull-Scale Propellers in the Prwmnce of a Radial and aLiquid-Cooled Engine NacelIer Including Tsats of Two Spi

34、n-ners. T. R. No. 642, N. A. C. A., 1938.Anon.: Comparison of Wind Tunnel Tests with Flight Testson a Number of Detachable Blade Propellers Made from. .the same PIan Form. A. C. I. C., vol. VII, No. 632 (A. C!.T. R. No. 2943), 1920.Biermann, David, and Hartman, Edwin P.: The Effect ofComprwibiLity o

35、n Eight Full-scale Propellem Operating inthe Take-Off and Climbing Range. T. R. No. 639, N. A.C. A., 1938.Wood, Donald H.: FuU-Scale” Tests of Metal Propellers atHigh Tip Speeds. T. It. No. 375, N. A. C. A., 1931.Stack, John: The N. A. C. A. HighSpeed Wind Tunnel andTeds of Six Propeller Sections. T. R. No. 463, N. A. C. A.,1933.Lindsey, W. F.: Dmg of Cylinders of Simple Shapes. T. R.No. 619, N. A. C. , 1933.!2691424%23Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-

copyright@ 2008-2019 麦多课文库(www.mydoc123.com)网站版权所有
备案/许可证编号:苏ICP备17064731号-1