natural convection results

natural convection results - 518 Table 12-1 Functions F and...

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Background image of page 2
Background image of page 3
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 518 Table 12-1 Functions F and 0 and Derivatives for Pr = 1‘ [5] —————-———_—_______+_ n F F ' F ” 0 0 ’ ——-—-—————_—_—_———__4_ 0 0.0000 0.0000 0.6421 , 1.0000 ‘ —0.5671 0.1 0.0030 0.0593 0.5450 9 0.9433 —0.5669 0.2 0.01 15 0.1092 0.4540 0.8867 —0.5657 0.3 0.0246 0.1503 0.3694 0.8302 —0.5627 ‘ 0.4 0.0413 0.1833 0.2916 0.7742 —0.5572 1 0.5 0.0610 0.2089 0.2208 0.7189 — 0.5488 0.6 0.0829 0.2277 0.1572 0.6645 -0.5371 0.7 0.1064 0.2406 0.1008 0.6116 -O.5221 3 0.8 0.1308 0.2481 0.0516 0.5602 —0.5038 0.9 0.1558 0.2511 0.0093 0.5109 ~0.4826 : 1.0 0.1809 0.2502 ~ 0.0263 0.4638 - 0.4589 1.1 0.2058 0.2461 — 0.0557 0.4192 — 0.4330 1.2 0.2300 0.2393 - 0.0793 0.3772 —0.4056 1.3 0.2535 0.2304 —0.0975 0.3381 *0.3772 1.4 0.2761 0.2199 — 0.1110 0.3018 - 0.3484 1.5 0.2975 0.2083 —0.1203 0.2684 —0.3 197 1.6 0.3177 0.1960 —0.1260 0.2379 *0.2915 1.7 0.3367 0.1832 —0.1287 0.2101 ~0.2642 1.8 0.3543 0.1708 —0. 1288 0.1850 —0.2382 1.9 0.3707 0.1575 —0.1268 0.1624 - —0.2136 2.0 0.3859 0.1450 —0. 1233 0.1422 ~O.1907 2.1 0.3997 0.1239 —0.1185 0.1242 —0_. 1695 2.2 0.4125 0.1213 —0.1127 0.1082 ~0.1501 2.3 0.4240 0.1 104 -— 0.1064 0.0941 —0. 1324 2.4 0.4346 0.1001 — 0.0997 0.0817 “0.1 164 2.5 0.4441 0.0904 ~0.0928 0.0708 —0. 1020 2.6 0.4527 0.0815 “0.0859 0.0613 -0.0892 2.7 0.4604 0.0733 -~ 0.0791 0.0529 —0.0777 2.8 0.4673 0.0657 ~0.0725 0.0457 *0.0676 2.9 0.4736 0.0588 —0.0662 0.0392 “0.0587 3.0 0.4791 0.0524 — 0.0602 0.0339 — 0.0509 3.1 0.4841 0.0467 —0.0546 0.0291 —0.0441 3.2 0.4885 0.0415 — 0.0493 0.0250 *0.0381 3.3 0.4924 0.0368 - 0.0444 0.0215 — 0.0329 3.4 0.4959 0.0326 —0.0399 0.0185 ~0.0283 3.6 0.5016 0.0254 - 0.0321 0.0136 —0.0210 3.8 0.5061 0.0197 —0.0255 0.0009 —0.0155 4.0 0.5096 0.0151 —0.0202 0.0072 —0.01 15 4.2 0.5122 0.01 16 — 0.0158 0.0053 —0.0084 4.4 0.5143 0.0087 —0.0124 0.0038 ~-0.0062 4.6 0.5158 0.0066 —0.0096 0.0027 —0.0045 4.8 0.5169 0.0049 *0.0075 0.0020 — 0.0034 5.0 0.5177 0.0035 —0.0057 0.0014 - 0.0024 5.2 0.5183 0.0025 —0.0044 0.0010 -0.0018 5.5 0.5189 0.0014 —0.0029 0.0006 —0.0011 6.0 0.5194 0.0004 ,—0.0014 0.0002 — 0.0005 6.25 0.5194 0.0000 — 0.0010 0.0000 - 0.0004 «my-mm- LAMINAR NATURAL CON‘ ‘With this definition the ‘5". The average heat-trai Eq. (12-3) since qwlmal Inasmuch as h =. Bx” ‘/ in Hence it follows from E in terms of the local Gr *7! In similar fashion the 1< to be given in terms of ‘3. Hence 7w ~ x'/‘ and it boundary layer, wall sh: The average shear stres: 516 NATURAL CONVECTION LAMINAR NATURAL or in terms of similarity variables, ’ which shows that h ' 3Wn=®8n_ NE: k(Tw Too) an Too) It is conventional to defi kc _ h = ~0’ 0 t; ( ) x1 /4 g IIMNIIII ‘ k II 7. II II II V II I. IV '- ‘55 II II II II ‘5 III-IE3..- I l a II A ‘IEEII III-I". ' 7 In A § ll a,tfi lungs MJZIIIIIIIMI WWII-IIIIIII Gr, 1/4 1 we)x Figure 12-2 Calculated dimensionless profiles in the laminar boundary layer on hot vertical flat plate in natural convection of (a) velocity and (b) temperature. (From S. Ostrach, NACA' Report 1111, 1953 [5].) NATURAL CONVECTION I 5 LAMINAR NATURAL CONVECTION—EXACT SOLUTION 517 which shows that h ~ x'V‘. From this the local Nusselt number is ' l/4 hx g l p r p Ix3 Nu : __ = _9r 0 ___°°_._w__ _ TOO) x k ( 4y2p°° w ' 1:: It is conventional to define the Grashof number Gr as kc V ' ‘3 l .7 ,i p ,~ pw x )xl/4 "it; er = ' . ,pw .‘ g > 18 20 22 24 boundary layer on a hot '7’) ‘4};r-rperature. (From S. 3:} —1 a Figure 12-2 (Continuedi) ...
View Full Document

Page1 / 3

natural convection results - 518 Table 12-1 Functions F and...

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online