1、Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-NASA TECHNICALMEMORANDUMNASA TM X- .J_-!-Lanqley Research Center_-_,_._L_V)r_ _,;_, ._,._;A-._,_.i t,i_._ s_ FAmUI/ .5:_,_.- ,NPUIBRANCH ,.:i7“,2 “L.Provided by IHSNot for ResaleNo reproduction or netwo
2、rking permitted without license from IHS-,-,-TABLE OF CONTENTSi.0 INTRODUCTIONi.i GeneralI.2 Backgroundi.5 Joint FAA-USAF-NASA Runway Reseerch Programl.h Test Teami,5 LogisticsI.6 Purpose2.O TEST_2.1 Aircraft2.2 Irlagonal-Braked Vehlclej I_V2. Mu-_ter2.h Wettlng Equil_mm_2.9 Miscellaneous Equipment3
3、.0 TEST PROCEDURES3-i Test Sequence3.2 Wetting Procedure3.5 Water Depth and Atmospheric Data Measurements5.4 Aircraft Test Procedure5._ DBV Test Procedure),6 Mu-Meter Test _oegdure4.0 DATA REDUCTION PROCEDURES4.1 Aircraft4.2 Diagonal-Braked Vehicleh. 3 Mu-Meter-,L!:i!,JVL i_xProvided by IHSNot for R
4、esaleNo reproduction or networking permitted without license from IHS-,-,-L.h Average Rtu:wav_T,:st Section Water Depthq.O ,RESU.%-:“ .i2 P!:_,“:, : _7 “:5 6 H:us,:cn T + . _*: . Ai:S5.7 Pre!iminar_- Results - Aircraft5.8 Preliminary/ Results - DBV/DBV Correlation5.9 Preliminsa-_ Results - _ga-Meter
5、/Mu-Meter Correlation5.10 Preliminar_v Results - DBV/r_9-Meter Correlation5.11 Preliminary Results - DBV/Aircraft Correiation5.12 Preiiminar_ Results - Mu-Meter/Aircraft Correlation5.i3 Preliminary Results - Houston Grooved Runway6.0 REFEPZ_C_7.I Ap:. ., t_tg_ : x .=c_ to :,hisorocedt_e %as _rc, -,_
6、 :, :_:_._ “.).e =: -“ _:,-_. th,-_ . 3 . r_,._, _;0;_On three occssi,?:_s “.:_ea(: _“ ex_t _ two stops were possible, other secments of the testsection were measure_ on subsequent aircraft tests, if needed. Basic DBVdata for the dr:.- surface tests are included in table VII, and data for wetsurface
7、 tests are included in t_b!o _CfYI. ?_!,ie _,qli sho,s the test resultsin relation to the rice _f the _.ircrsft test._._ Mu-Meter Test ?rm:ed,_e - _ne Mu-Meter was operated in accordancewith procedures _eveope_ in the :_:-i_ed _(incdOr_! (_e _. f). For each run theto_in L vehicle was _cce,-_ratrd to
8、 t-,he seec.-,ed :cr_/n_: _elocit), _sually _0mph, prior to enter!n, t_.etest section. %q;is velocity was held cons%ant forthe run %hrouu_h the test section. Some data were also obtained at speedsother than he mph. The basic Mu-Meter data for the dr“ surface conditionsare included in table VII and t
9、he basic wet _urface data are included intable VIII. The latter is sho%_n in a time relationship to the aircraft test.4.O DATA REDUCTION PROCEDURES_.I Aircraft - The nose wheel revolution couqter ;2J.ite ri_, :he te_t _ro, rsz; _sp,- standa_-d rou_lasfilm data processln pro._-,._d:_-es. Vsl:.es of t
10、_fa_.:_._ai:pilcatlon TOU:.d speed andaircraft sto_!i_l dJF,*9nco o,tai,_ed iv _is co,_te _re also listed intable IX._.i.(_ At Edwards AFL, t_,c I_SAY :-_t.aLned meas_r_:ments of aircraft urekeapplication spee6 _nd st,:,?_:i: 5ist_nc_ J_i_ “ _t run_ f_o_a d_a _!_inedby operatin_ its f!x_,d (towcr) g
11、round photothcodoli_c eq_.ipmcnt. _Is was inaddition to date acq_Ired _t each test runway be ol_rs.in; its portatle_ound phototheodolitc 4_re through the data pointsIma Influence(1 by %he shml_ Of the _dlvldual run_ shown in figure 21 whichshow that at the lower values of VB the dry stopping distanc
12、e data is inde-penden_ of wIgh_ effects. The data_catter is Influence,_ by the same factorswhich were identified in 4.1.8.1. The plots are used in the same manner asthe WV2Bg plots to determine the aircraft SDR.4.1.8.5 The third _ed_on method used follows the Douglas Ai;_.a_Co. procedure of reducin;
13、 aircraft flight r_est data to sea level; zero wind,standard weight condi .!:_s. _ne f_o_41n_N OGU_LiOnS we-e_ used:whereSew = stopping distance et se_ level, zero w_nd, standard weight WS, feetS = actual test atopplm- distance, feetgVw = wind velocity parallel to the airplane centerline (+ head win
14、d, -tallwind), feet per second!0Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-t = time from brake a pp!ic_tion to stop, sec,:_:dsd,vAt = _w where VdV/dt “-q_y : runway sl_joe, rg = 52.ii_f: _ecW S = aircraft ,:ra “ val _ equation, a!, order ,_ ,-:
15、. :-V drjstoppln distance apDear_ d to vary with ambient air tem_eralure in accordancewith %he equation:S _ :LO._+ !.k_T (i0)DS = DHV dry stopping distance, feetDwhe_-eT = smbie:_t sir temperature, F.Since the time of the tests from w,_ich equ._o_+_ (10) was esi_b!ishe, _le “=. havebeen numerous oth
16、er tests which _ave produced dat_. for considersticn in eval-uating this phenomenon. These dst8 are snwn i:_ f_bles XI lhrou_h XIV 8ndhave been examined to ascertain pot:nti_. tr,zt,d5 by _lotting Ms shcwn in _“ .31. The plot. af fi F. _nd for this reason the fatrin_ of figure32 was used in determln
17、ln/ D!V dry stoppinF distance Sate i_t:_Is _,sper foruse with wet stopping distances to compute the b_V ?LR.h.2.5 To understand why the d_ta produce a value at ,he lower tempera-t_s that is higher then that shown in referenc+ 3, the effect of frictioncoefficient, u, on stopping distance of the DPV w
18、as examined. Evsluoting theb_sic stopping distance equation:2as :Vl (n)D 2,16Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-where_D = incremental stopping distance2 = brake applicatio_ _.ed squaredVI2= C il,_ + _)D _D= air vel3eit 7= O.9_ (from chap
19、ter 12, “Fluid _gnamic Drag,“ by Dr. Ing. S. F. Hoerner)S = 20 ft2 (frontal area of a modern full size sedan automobile)p = air density, ib/ft 3the plot of figure 33 was obtained which shows that:I. The minimum stoppln_ dlstance which can be realized by the DPV wlth= 1.0 Is 23u feet.The average dr/s
20、toppinF distance oi_tat:_ed from test date onnumerous runways is the result of an average .eriction coefficient,_,= O._7 beinf_ developed betwee:-_ the slidint- tire and the runwaysurface over the tenperature ren.-e of C: to _3 F.As stated in h ) _ fa_rin, “_-,_-_ _ _,as qsed lu this D,r_ for “m_.).
21、_er_ odeterminlnt- the D.qV st,opi:_i-dlstan_e rag.los, wet/dr_,. A review o: the 9- -data which is contai_ed _n _,_,bWF-itt; has l,ee_ m_de to deLermine _., _.,.:D_V SDRs obtained in that re?oct should be cha:_,-ed. It was d_1._.m_ _(.dzhatsince of the DEV (rv.,dat8 Fa_;_-_,._durinF th,_ _:.-“.,tes
22、ts were 3:ta_.nedat temperatures abcve ,C F, little .aT T_o practical error %ould he _:trcdueedif either curve were used. (7_e ?_;_:r,_ _). L_hus it has be_an determined thatno changes are required to zhe i_fV ;DRs ohtai._,ed durlv,g the B-72v tests,_.2.h As can be seen in table VIII, the DBV stoppi
23、nc distances as wellas the Mu-Meter average friction readings vary considerably wlth the time oftest following the artificial wetting of the runway. These varlatlo:.s uithtinge are due to vehicle activity or water drai:_age from the surface whichreduces the effective water depth at the time of the t
24、est. Thus, for corre-lation between aircraft and the rrelation Tests - Prior tc c_mme:cing aircrafttests at NASA WalioFs Staticn, a series of comc_ative tests were conductedusing two DBVs and two Mu-Meers. The NASA DBV and _he FAA DBV, the USAFMn-Meter and FAA Mu-Meter were the vehicles tested. The
25、series of tests weremade on the test runway 04/22 and on r_nway 10/28 at Wallops _nder dry, wet,and ice-covered surface conditions. The data from these tests are presentedin table XVl. A discussion of these data follow in section 5.19Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
