Transactions

COLBURN, COGHLAN—HEAT TRANSFER TO HYDROGEN-NITROGEN MIXTURES INSIDE TUBES 565RunNo.GasT A B LE 2E X P E R IM E N T A L DATA^1 t 2 t .F F F6cl b p e rh rA 1 A ir * 7 4 .4 1 9 0 .4 2 1 1 .8 0 .2 1 32 7 5 .6 1 9 0 .4 2 1 1 .8 0 .2 4 73 7 5 .0 1 8 9 .0 2 1 1 .8 0 .3 1 14 7 5 .2 1 8 7 .0 2 1 1 .8 0 .3 7 35 7 5 .2 1 8 4 .8 2 1 1 .8 0 .4 4 36 7 5 .2 1 8 3 .8 2 1 1 .8 0 .5 3 6B 1 A ir** 7 5 .3 1 8 9 .4 2 1 1 .6 0 .1 9 02 7 6 .1 1 8 9 .8 2 1 1 .0 0 .1 7 53 7 4 .9 1 8 8 .0 2 1 1 .6 0 .2 6 14 7 5 .3 1 8 6 .7 2 1 1 .0 0 .2 9 15 7 4 .3 1 8 6 .2 2 1 1 .6 0 .3 5 26 7 3 .4 1 8 4 .0 2 1 1 .1 0 .3 8 97 7 4 .8 1 8 3 .7 2 1 1 .0 0 .4 3 38 7 5 .3 1 8 3 .3 2 1 1 .0 0 .4 2 99 7 4 .7 1 8 1 .3 2 1 1 .3 0 .5 2 610 7 3 .4 1 8 0 .4 2 1 1 .0 0 .5 3 311 7 5 .6 1 7 9 .3 2 1 1 .3 0 .5 9 5C 1 N3 6 7 .1 1 8 8 .8 2 1 2 .4 0 .2 4 52 6 7 .1 1 8 8 .0 2 1 2 .2 0 .2 5 53 6 8 .4 1 8 5 .8 2 1 2 .4 0 .3 1 84 6 7 .5 1 8 5 .0 2 1 2 .4 0 .3 7 65 6 7 .5 1 8 3 .3 2 1 2 .6 0 .4 6 16 6 9 .3 1 8 0 .0 2 1 2 .4 0 .5 6 37 7 3 .0 1 7 9 .2 2 1 2 .8 0 .6 5 4D 1 8 .8 5 $ 7 4 .5 1 9 3 .0 2 1 1 .1 0 .2 8 52H2 7 4 .5 1 9 0 .6 2 1 1 .1 0 .3 5 33 7 4 .5 1 8 8 .4 2 1 1 .1 0 -4 6 54 7 4 .3 1 8 6 .4 2 1 1 .1 0 .5 2 95 7 4 .1 1 8 5 .3 2 1 1 .1 0 .5 9 56 7 3 .8 1 8 3 .6 2 1 1 .1 0 .6 3 77 7 4 .3 1 8 3 .8 2 1 1 .3 0 . 713E 1 2 8 .6 # 7 4 .8 1 9 7 .8 2 1 2 .0 0 .3 2 22 «3 7 5 .0 1 9 5 .4 2 1 2 .0 0 .4 5 13 7 4 .1 193 .8 2 1 2 .0 0 .5 2 94 7 5 .3 1 9 2 .0 2 1 2 .0 0 .6 2 85 7 4 .8 1 9 0 .6 2 1 2 .0 0 .7 5 56 7 3 .3 1 8 9 .8 2 1 2 .0 0 .8 0 3F 1 37* 7 3 .0 1 9 5 .2 2 1 2 .0 0 .2 1 62 H3 7 1 .8 1 9 7 .2 2 1 2 .0 0 .4 3 03 7 3 .3 1 9 5 .6 2 1 2 .0 0 .5 5 24 7 3 .5 1 9 3 .8 2 1 2 .0 0 .6 3 85 7 3 .7 1 9 2 .4 2 1 2 .0 0 .7 3 56 7 0 .5 1 9 1 .6 2 1 2 .0 0 .8 4 4G 1 4 3 .9 $ 7 3 .4 1 9 8 .8 3 1 1 .1 0 .3 0 42 Hs 7 4 .3 1 9 8 .4 2 1 1 .3 0 -4 6 83 7 3 .6 1 9 6 .4 2 1 1 .3 0 .6 1 04 7 3 .7 1 9 5 .2 2 1 1 .3 0 .6 8 35 7 3 .7 1 9 4 .0 2 1 1 .3 0 .7 9 46 7 3 .6 1 9 3 .2 2 1 1 .5 0 .9 2 07 7 3 .4 1 9 1 .6 2 1 1 .3 1 .0 0 6H 1 55% 7 3 .8 1 9 1 .6 2 1 2 .0 0 .2 6 32 H3 7 3 .6 201 . 0 2 1 2 .0 0 .3 6 53 7 3 .8 2 0 0 .2 2 1 2 .0 0 .4 6 04 7 1 .1 199 *0 2 1 1 .3 0 .5 1 85 7 1 .6 1 9 7 .82 1 1 .3 0 .6 5 66 7 2 .0196 .6 2 1 1 .5 0 .7 2 27 7 2 .01 9 5 .22 1 1 .8 0 .8 3 3I 1 8 6 . 8j£ 7 3 .7 2 0 0 .62 H3 7 3 .9 192 .23 , 7 3 .1 2 0 0 .04 7 3 .2 1 9 9 .55 7 1 .4 197 .82 1 2 .0 0 .3 1 32 1 2 .0 0 .4 4 92 1 2 .0 0 .6 1 62 1 2 .0 0 .7 5 02 1 2 .0 0 .9 5 5J 1 9 4 .4 5 7 1 .4 1 9 8 .8 2 1 1 .5 0 .3 3 12 H3 7 3 .5 1 8 8 .4 2 1 1 .5 0 .4 5 53 7 2 .1 1 8 7 .02 1 1 .5 0 .5 5 84 7 1 .0193 .02 1 1 .5 0 .6 7 05 7 1 .4 1 9 4 .2 2 1 1 .5 0 .8 8 5K 1 98JS 7 1 .6 1 9 6 .2 2 1 1 .7 0 .3 7 52 h 3 7 1 .3 1 8 7 .22 1 1 .7 0 .4 5 53 7 3 .81 8 4 .62 1 1 .5 0 .5 7 94 7 3 .81 9 0 .62 1 1 .5 0 .7 2 45 7 3 .71 9 2 .02 1 1 .5 0 .8 2 96 7 3 .31 9 2 .02 1 1 .5 0 .9 1 8*Alr from compressed air line.**Air recirculated by 'blower.C A LC U LA TE D R E SU L T Swl b p e rh rq Gx 100jDG6 .4 8 0 . 0 0 .0 0 3 8 8 38007 .6 5 + 1 .0 0 .0 0 3 8 6 44909 .9 0 +1 .1 0 .0 0 3 7 3 58201 2 .3 3 +0 . 2 0 .0 0 3 5 5 73001 5 .2 2 - 1 . 3 0 .0 0 3 3 8 90501 7 .3 4 + 1 .8 0 .0 0 3 3 1 109505 .2 3 + 1 1 .3 0 .0 0 3 7 8 30506 .1 6 - 1 3 . 8 0 .0 0 3 8 6 36008 .2 9 + 5 .8 0 .0 0 3 6 5 48409 .6 5 - 0 . 4 0 .0 0 3 5 8 56401 1 .6 2 + 1 .2 0 .0 0 3 5 3 68001 3 .8 5 - 4 .8 0 .0 0 3 3 8 81001 5 .1 0 + 0 .9 0 .0 0 3 3 7 88001 6 .2 1 - 6 . 4 0 .0 0 3 3 3 95001 8 .4 0 + 2 .8 0 .0 0 3 1 5 107501 9 .1 0 0 . 0 0 .0 0 3 1 3 112002 1 .9 0 + 1 .3 0 .0 0 3 0 0 128006 .6 5 + 5 .0 0 .0 0 3 7 8 40507 .8 0 - 3 .9 0 .0 0 3 7 3 48009 .5 5 + 0 . 3 0 .0 0 3 6 0 58801 1 .6 5 - 0 . 7 0 .0 0 3 4 6 71601 4 .1 1 + 3 .0 0 .0 0 3 3 3 87001 8 .4 4 + 1 .6 0 .0 0 3 1 0 113402 2 .7 0 - 0 . 2 0 .0 0 3 9 8 149507 .8 1 - 1 .2 0 .0 0 3 7 3 51309 .9 1 - 2 .3 0 .0 0 3 5 9 65101 3 .1 7 + 4 .3 0 .0 0 3 3 9 86401 5 .8 0 + 0 .8 0 .0 0 3 3 4 103601 8 .2 1 - 0 . 2 0 .0 0 3 1 5 119502 0 .1 5 + 1 .8 0 .0 0 3 0 4 122402 2 .0 7 + 1 .9 0.00.297 144806 .9 2 + 3 .8 0 .0 0 3 7 8 46409 .9 3 + 1 .8 0 .0 0 3 5 2 66S01 2 .0 0 + 0 . 4 0 .0 0 3 3 9 80501 4 .4 0 + 2 .6 0 .0 0 3 2 1 96601 7 .5 8 + 2 .5 0 .0 0 3 1 1 117901 8 .8 8 + 1 .2 0 .0 0 3 0 5 126704 .2 3 - 7 .1 0 .0 0 3 4 3 2900a . 38 - 2 .4 0 .0 0 3 6 3 57601 0 .9 0 - 0 .4 0 .0 0 3 4 6 74901 2 .9 7 - 1 .1 0 .0 0 3 3 0 89001 5 .1 5 - 0 . 5 0 .0 0 3 1 7 104001 6 .9 0 + 1 .4 0 .0 0 3 1 3 116105 .0 5 + 2 .3 0 .0 0 3 8 0 35008.13* - 3 .3 0 .0 0 3 7 3 55401 0 .7 2 - 6 .6 0 .0 0 3 5 0 74301 2 .1 6 + 3 .5 0 .0 0 3 3 8 84301 4 .3 7 + 3 .2 0 .0 0 3 3 7 99701 6 .4 6 + 5 .6 0 .0 0 3 1 9 114201 7 .9 4 + 7 .7 0 .0 0 3 0 8 134503 .6 4 + 4 .7 0 .0 0 3 9 3 36305 .1 6 - 2 .1 0 .0 0 3 8 7 37306 .4 4 + 1 .4 0 .0 0 3 7 5 46407 .4 0 + 0 . 3 0 .0 0 3 7 3 53309 .0 4 + 5 .0 0 .0 0 3 5 8 65301 0 .3 8 + 2 .3 0 .0 0 3 4 1 74701 2 .1 5 + 2 .6 0 .0 0 3 3 6 87501 .7 9 - 4 .4 0 .0 0 3 7 3 16902 .7 2 - 1 .5 0 .0 0 2 9 0 25803 .7 9 - 7 .3 0 .0 0 3 6 5 36004 .6 7 - 7 .4 0 .0 0 3 5 8 44305 .8 8 - 0 . 4 0 .0 0 3 4 1 55801 .3 0 - 7 .0 0 .0 0 4 0 8 14451 .8 4 - 2 .4 0 .0 0 3 0 7 30302 .2 9 - 1 .4 0 .0 0 2 9 7 25252 .6 7 - 3 .7 0 .0 0 3 4 7 29402 .04 - 8 .6 0 .0 0 3 5 8 31301 .1 0 - 1 0 .3 0 .0 0 3 9 2 13171 .5 6 - 1 6 .4 0 .0 0 3 3 0 18681 .9 0 - 8 . 7 0 .0 0 3 0 9 22812 .2 1 - 5 .6 0 .0 0 3 5 6 26412 .4 7 - 4 .1 0 .0 0 3 7 0 29613 .7 0 - 6 .0 0 .0 0 3 7 1 3330Fdata of Nusselt (6, 7) The friction data areshown in Fig. 7 to be in excellent agreementwith the literature. In order to check a possibleeffect of the blower in recirculating thegases, heat-transfer data on air were obtainedby using both air from the compressed-airline in the laboratory (where fluctuationshad been well smoothed out by a surge tankand some 100 ft of pipe) and air recirculatedby the blower. There is no appreciabledifference in the results as will be seenfrom Fig. 7, and, furthermore, the data areseen to be in excellent agreement with thoseof Nusselt.A plot of data on pure nitogen, shown inFig. 8, is practically identical with that of thedata on air shown in the previous figure. Incalculating Reynolds’ numbers, values of viscositywere obtained from Fig. 1 and thencorrected to the mean gas temperature inthe tube, the latter correction meaning anincrease in the value of viscosity by about 10per cent.Data on mixtures of hydrogen and nitrogenare shown in Figs. 8 to 12. In calculating theordinates for these plots, values of the Prandtlnumber for the mixtures were taken fromFig. 2. For these gases, the value of Prandtl’snumber is practically independent of pressureand temperature over moderate ranges,so that the values given in Fig. 2 for 70 F couldbe satisfactorily used for the temperaturesencountered in these experiments. The closeagreement of the results in Figs. 8 to 12,with the previously plotted data on air, andwith the line representing the Nusselt airdata, is proof that the proper value touse in calculating heat transfer for mixturesis the value of the Prandtl number of themixture.As final indication of the necessity of includingthis factor, Fig. 12 shows h/ (CVG) plottedversus Reynolds’ number. The strong divergenceof the lines for the different mixturesproves the importance of the Prandtl numberof the mixture in bringing the results intoagreement.The effect of the Prandtl number can beshown, from the results in Fig. 12, to be atleast as important as the 2/a power, as oftenused in the exponential formula.......«In the range of values of Prandtl’s numberbetween 0.45 and 0.7, the Prandtl equationwould predict about one half this effect, andthe von K&rmdn equation something in betweenas shown by Chilton (2). While theseresults in themselves may not be sufficient todisprove these latter two equations, they areat least indications that the simple exponentialtype is more satisfactory for gas mixtures