A special debt sf gratitude ie also due to the Bureau of Berronautics of the Department of the Navy which 8upp011"$@d lit three ysase sf sltdy graduates,. Since tks approach gas velocity it4 very O J T ~ B P B 0% magdtUB11e more greater than bPanraa flame barwing, ebe flame m-uat bs s$akbilized or held in comb~skce~n ~ b r n b e r by the physical mechanism of rubber. aone c~lld co~mabustfbla mla%erfa8 mix@@ with hat recircdatia~~ aonB g a ~ , The reaction c'%9emiea$ t&ss p b e s mainly in the eons of mixing at the edge8 sf the wake and racir- cubtion gae esnaiste area almost sHaeirely e p~(~ducth3 of ComaCaub4- tion), From about %ha bottom 0% of the area of recirculation the flame spreads domrsltream and eontintta in aprsad in the unburnt gas.
Unfortunately, little quantitative information is available regarding assembly efficiency. some iatareetiga@ioae $bats were mhslde flama ~preading, w~ssh were removed at BOW R e p o l d s numball in %~ma;sBd stale equipment*. The work of Pegre)in* st ale was valuable as it gave general data C Q ~ C B J ~ E I P P ~ ~ some of the active ingredients 5 and t i m e average data for the effective~msfnationh date, However, it seemed to irave An indication that did not require time-averaged sampling pkOC%1632 10 of the collected data, could enable obtaining more accurate information on the mecltsiani~m of the spread of the ftrarn. Most of the data were obtained by firing the beams of Sckslfesren pliaatag~aphs of the expanding flame through vyccsr glass.
The fuel was d r a m dram tanks whkh were; greaeurized to 1100 psi with the use of parasBusa nitrogen bottles and injected through a mzsrtal spray into the air supply line 30 feet up the 9ntreszm of the plenum c b m b e r * TMc is made to provide proper timing for fuel cooling and a mixture of air forward beaten. Tfna squ.re duct sactian ut.a@ 38.7 Faachee Bang, T o high velocity air diffuee etrsaam entc;rring plenum chamber,.
A BH-6 lamp tightly connected was used, and the focal lengths of the two PO Inch diameter concave mirrors were 80 inches and 96 inches. Hmaemetch, since the electrical circuit and physical layout of the optical system were conventional. The bombdary used in this study to determine the wake width was the location of the intesaectfslns of the bumps on the flame from the gurfaeo, Fig.
Effsrta were m&e to suppreae a~@tfUations with c h ~ g h g lakatton of fiamehofdsmt in the channel snd by &taring the. During the inva &f ga- tbom of the inrflusnccs of the exit ccpxaditioaea, it was found tksat m y ehokiag a t the end dowe3istrc30m of the channel caused a markad i n e r e a l e iks. T h present in the inarestfg113tb:i~n of a concern& 4 t h Premature injury of the dawn of w&s od tlhf s ragaan.
A study of the SeMis pin phot@glpaph@ inakered t b k the critfcd velocity mermtfsned bo oceurnr~d at the transition from laminar to Wrbdsng n o w In the flame. Hewca, this sesdtas discussed rabbit may not be representative of the wake further af&rtrsam.
1% if8 believed that the: difference in wake width@ bs$wesn channels is duo to a diffsrsncc in the anamber of water cocaled. In the f l ~ w field in tba imma38ilaka w&e of the name holder, S$ezdO@s by Foster (1 3) has s h o w the liquid d p a m $ c effeelkb are) prd@minail$t in determining $he location of the w&s edge bomdbg the re~ircFZ11~tf~n zone and that the distribution x a a s a m much more rapM ae l a w. The pressure ea~fficlant was f ~ u n d in g a n e ~ a l to be greater at Itow epaeda amp9 to reduce rapfay 81 the vsla~fty Pfncreas~d to the critic & V&UO.
T M s gen~ratB picture waits ccor- rac% for EBhl sta$iona d a m 8 t r e m of %he fhamehslider, But for station@ elom to the container, the: perturb& region at any wake edge over%apped at the channel eem% t @rUns and hence the region of conetant tctd hsacf wars not observed,. The minimum a s r m a l k a d total head deficit in the central region was rsughey l, P and was dependent on atation or approach s t r e a m velocity, The o r d e r of magnitude of this %O@S easily explained by &ha fouawing andir~y@i@, . H e r are the local dynamic parameters of the unburned gas, and pb and pu are the burned and unburned gas l dctnaities.
The anaPyei8 and e q e r i r n e n t al rsrsufto reveal that the largest past of the observed total head loss is due to the eombuls $ isna continues and that the flame holder drags a small part of the problem in repairing the tgla;alL. The blue aging density caused a major change in the dynamic bustle and therefore in the overall beauty. The measurements in the currently stable regions are thought to be reliable, although the overall measurements were.
Velocity and Mach N m b e r, Tho valiocity a d Mach gleambar feiddas for f h w outside tba wake was established by the 4 corresponding tot& and static pressure flames, Pressure data @hawad at Mach numbers and the velocity profiles in the maburnt mktur w e r e 919-. Exact d~termfnatbon of Mach number a d velocity inside the w&e was impoeefble b s c a u ~ e the temperature profiles were unknown. The operating condition is the same as that used to obtain the total prior data for F i g , 26 .
A dste~mffaation of the( vdocity inside &he wake ica much more d u f i c d t due tg, the fact that tha velocity dependence of the a e s m e d temperatwe profaa ie v e r y grreEae, Hswsvfsr, a to qwPitaof@ f@ mas determine. the wake E$I a fmoction sf distance, the maaa PTow outaids the wae wae determined at various This rssdt has \APIQBR linked to the fact that f h s wake widah i s also hdapendsnt of upggream vsfocity imply$ that the maas must directly in the w&e bs propor-.
The data presented in this report have sasitabkiehsd tb following image of the burning w&8 ON a blaP%f body flame holder, In the. Further dowstrieam, the w&e epreadlng rate ie s m d l and for a given flow condition isr independent of diet race of the flamehouar. For a turbd~nt w e the laeation sf the wake bcaundasi~~ independent cabin is the upotreani mixture v @ % ~ ~ i f y m d o d y weak dapsn- dent on the fuel-air ratio, and the total prceEalEaure deficit and tba.
