{"id":15911,"date":"2026-11-12T15:03:33","date_gmt":"2026-11-12T07:03:33","guid":{"rendered":"https:\/\/huaxinfountain.com\/?p=15911"},"modified":"2026-11-12T17:39:52","modified_gmt":"2026-11-12T09:39:52","slug":"reynolds-number-laminar-fountain-jets","status":"publish","type":"post","link":"https:\/\/huaxinfountain.com\/vi\/reynolds-number-laminar-fountain-jets\/","title":{"rendered":"S\u1ed1 Reynolds trong c\u00e1c tia phun d\u1ea1ng t\u1ea7ng: H\u01b0\u1edbng d\u1eabn th\u1ef1c ti\u1ec5n"},"content":{"rendered":"
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<\/div>

\u0110\u1ec3 t\u1ea1o ra m\u1ed9t tia n\u01b0\u1edbc \u0111\u00e0i phun m\u01b0\u1ee3t m\u00e0 t\u1ef1a nh\u01b0 th\u1ee7y tinh, ch\u1ec9 ri\u00eang \u00e1p l\u1ef1c n\u01b0\u1edbc l\u00e0 ch\u01b0a \u0111\u1ee7. H\u00ecnh d\u00e1ng c\u1ee7a tia n\u01b0\u1edbc c\u00f2n ph\u1ee5 thu\u1ed9c v\u00e0o c\u00e1c \u0111i\u1ec1u ki\u1ec7n d\u00f2ng ch\u1ea3y b\u00ean trong v\u00f2i phun, s\u1ef1 \u1ed5n \u0111\u1ecbnh c\u1ee7a d\u00f2ng n\u01b0\u1edbc khi tho\u00e1t ra kh\u1ecfi mi\u1ec7ng v\u00f2i, c\u0169ng nh\u01b0 nh\u1eefng t\u00e1c \u0111\u1ed9ng g\u00e2y nhi\u1ec5u m\u00e0 n\u00f3 g\u1eb7p ph\u1ea3i trong kh\u00f4ng kh\u00ed.

S\u1ed1 Reynolds (Re) l\u00e0 m\u1ed9t \u0111i\u1ec3m kh\u1edfi \u0111\u1ea7u h\u1eefu \u00edch \u0111\u1ec3 t\u00ecm hi\u1ec3u c\u00e1c \u0111i\u1ec1u ki\u1ec7n n\u00e0y. Tuy nhi\u00ean, b\u1ea3n th\u00e2n n\u00f3 kh\u00f4ng th\u1ec3 d\u1ef1 \u0111o\u00e1n \u0111\u01b0\u1ee3c ch\u1ea5t l\u01b0\u1ee3ng h\u00ecnh \u1ea3nh c\u1ee7a m\u1ed9t tia n\u01b0\u1edbc ch\u1ea3y t\u1ea7ng.<\/strong> Thi\u1ebft k\u1ebf v\u00f2i phun, s\u1ef1 nhi\u1ec5u lo\u1ea1n \u1edf th\u01b0\u1ee3ng ngu\u1ed3n, s\u1ee9c c\u0103ng b\u1ec1 m\u1eb7t v\u00e0 c\u00e1c \u0111i\u1ec1u ki\u1ec7n v\u1eadn h\u00e0nh c\u0169ng c\u1ea7n \u0111\u01b0\u1ee3c xem x\u00e9t.

B\u00e0i vi\u1ebft n\u00e0y gi\u1ea3i th\u00edch c\u00e1ch t\u00ednh s\u1ed1 Reynolds, l\u00fd do c\u1ea7n th\u1eadn tr\u1ecdng khi \u00e1p d\u1ee5ng c\u00e1c gi\u1edbi h\u1ea1n truy\u1ec1n th\u1ed1ng c\u1ee7a d\u00f2ng ch\u1ea3y trong \u0111\u01b0\u1eddng \u1ed1ng, c\u0169ng nh\u01b0 nh\u1eefng y\u1ebfu t\u1ed1 m\u00e0 k\u1ef9 s\u01b0 c\u1ea7n xem x\u00e9t khi thi\u1ebft k\u1ebf v\u00f2i phun t\u1ea7ng v\u00e0 v\u00f2i phun n\u01b0\u1edbc nh\u1ea3y cho \u0111\u00e0i phun n\u01b0\u1edbc.<\/p><\/div><\/div><\/div>\n\n\n\n

\"Opposing<\/figure><\/div>\n\n\n\n
<\/div><\/div><\/div>\n\n\n\n

S\u1ed1 Reynolds trong th\u1ee7y l\u1ef1c \u0111\u00e0i phun n\u01b0\u1edbc l\u00e0 g\u00ec?<\/h2><\/div>

S\u1ed1 Reynolds l\u00e0 m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng kh\u00f4ng th\u1ee9 nguy\u00ean m\u00f4 t\u1ea3 m\u1ed1i quan h\u1ec7 gi\u1eefa c\u00e1c hi\u1ec7u \u1ee9ng qu\u00e1n t\u00ednh v\u00e0 hi\u1ec7u \u1ee9ng nh\u1edbt trong m\u1ed9t ch\u1ea5t l\u01b0u \u0111ang chuy\u1ec3n \u0111\u1ed9ng.

N\u00f3i m\u1ed9t c\u00e1ch \u0111\u01a1n gi\u1ea3n, n\u00f3 gi\u00fap c\u00e1c k\u1ef9 s\u01b0 hi\u1ec3u \u0111\u01b0\u1ee3c c\u00e1ch th\u1ee9c m\u1ed9t d\u00f2ng ch\u1ea3y v\u1eadn h\u00e0nh d\u01b0\u1edbi m\u1ed9t t\u1ed5 h\u1ee3p nh\u1ea5t \u0111\u1ecbnh g\u1ed3m v\u1eadn t\u1ed1c, k\u00edch th\u01b0\u1edbc \u0111\u1eb7c tr\u01b0ng v\u00e0 \u0111\u1ed9 nh\u1edbt c\u1ee7a ch\u1ea5t l\u01b0u.

\u0110\u1ed1i v\u1edbi d\u00f2ng n\u01b0\u1edbc ch\u1ea3y qua m\u1ed9t \u0111\u01b0\u1eddng \u1ed1ng tr\u00f2n, s\u1ed1 Reynolds th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 ph\u00e2n bi\u1ec7t gi\u1eefa d\u00f2ng ch\u1ea3y t\u1ea7ng, d\u00f2ng ch\u1ea3y chuy\u1ec3n ti\u1ebfp v\u00e0 d\u00f2ng ch\u1ea3y r\u1ed1i.<\/p><\/div><\/div><\/div>\n\n\n\n

S\u1ed1 Reynolds<\/th>Ph\u00e2n lo\u1ea1i d\u00f2ng ch\u1ea3y trong \u0111\u01b0\u1eddng \u1ed1ng theo c\u00e1ch truy\u1ec1n th\u1ed1ng<\/th><\/tr>
D\u01b0\u1edbi kho\u1ea3ng 2.000\u20132.300<\/td>D\u00f2ng ch\u1ea3y t\u1ea7ng<\/td><\/tr>
Kho\u1ea3ng 2.300\u20134.000<\/td>Chuy\u1ec3n ti\u1ebfp<\/td><\/tr>
Tr\u00ean kho\u1ea3ng 4.000<\/td>H\u1ed7n lo\u1ea1n<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
<\/div>

C\u00e1c ph\u1ea1m vi n\u00e0y l\u00e0 nh\u1eefng h\u01b0\u1edbng d\u1eabn mang t\u00ednh \u01b0\u1edbc l\u1ec7 \u0111\u1ed1i v\u1edbi d\u00f2ng ch\u1ea3y b\u00ean trong \u0111\u01b0\u1eddng \u1ed1ng. S\u1ef1 chuy\u1ec3n \u0111\u1ed5i ch\u00ednh x\u00e1c c\u00f2n ph\u1ee5 thu\u1ed9c v\u00e0o c\u00e1c nhi\u1ec5u lo\u1ea1n t\u1ea1i \u0111\u1ea7u v\u00e0o, h\u00ecnh h\u1ecdc \u0111\u01b0\u1eddng \u1ed1ng v\u00e0 c\u00e1c \u0111i\u1ec1u ki\u1ec7n v\u1eadn h\u00e0nh.

Ch\u00fang kh\u00f4ng n\u00ean \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng l\u00e0m c\u00e1c gi\u1edbi h\u1ea1n ch\u1ea5p nh\u1eadn chung cho di\u1ec7n m\u1ea1o c\u1ee7a tia n\u01b0\u1edbc \u0111\u00e0i phun sau khi r\u1eddi kh\u1ecfi v\u00f2i phun.
<\/strong>
V\u00f2i phun \u0111\u00e0i n\u01b0\u1edbc kh\u00f4ng ch\u1ec9 \u0111\u01a1n thu\u1ea7n l\u00e0 d\u00f2ng ch\u1ea3y trong \u1ed1ng \u0111\u00e3 \u1ed5n \u0111\u1ecbnh. N\u01b0\u1edbc \u0111i qua c\u00e1c \u0111\u01b0\u1eddng d\u1eabn b\u00ean trong, thay \u0111\u1ed5i h\u01b0\u1edbng ho\u1eb7c ti\u1ebft di\u1ec7n, r\u1ed3i cu\u1ed1i c\u00f9ng tr\u1edf th\u00e0nh m\u1ed9t tia n\u01b0\u1edbc t\u1ef1 do \u0111\u01b0\u1ee3c bao quanh b\u1edfi kh\u00f4ng kh\u00ed.

B\u1ec1 m\u1eb7t n\u01b0\u1edbc thu \u0111\u01b0\u1ee3c ch\u1ecbu \u1ea3nh h\u01b0\u1edfng b\u1edfi c\u00e1c \u0111i\u1ec1u ki\u1ec7n m\u00e0 m\u1ed9t s\u1ed1 Reynolds duy nh\u1ea5t kh\u00f4ng th\u1ec3 m\u00f4 t\u1ea3 \u0111\u1ea7y \u0111\u1ee7.<\/p><\/div><\/div><\/div>\n\n\n\n

<\/div><\/div><\/div>\n\n\n\n

C\u00e1ch t\u00ednh s\u1ed1 Reynolds cho m\u1ed9t tia n\u01b0\u1edbc \u0111\u00e0i phun<\/h2><\/div>

Ph\u01b0\u01a1ng tr\u00ecnh th\u01b0\u1eddng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng l\u00e0:

Re = VD \/ \u03bd<\/strong>

M\u1ed9t d\u1ea1ng t\u01b0\u01a1ng \u0111\u01b0\u01a1ng s\u1eed d\u1ee5ng \u0111\u1ed9 nh\u1edbt \u0111\u1ed9ng l\u1ef1c h\u1ecdc l\u00e0:

Re = \u03c1VD \/ \u03bc<\/strong>

\u1ede \u0111\u00e2u:

Re<\/strong> = S\u1ed1 Reynolds (kh\u00f4ng th\u1ee9 nguy\u00ean)
V<\/strong> = v\u1eadn t\u1ed1c n\u01b0\u1edbc trung b\u00ecnh (m\/s)
D<\/strong> = \u0111\u01b0\u1eddng k\u00ednh \u0111\u1eb7c tr\u01b0ng (m)
\u03bd<\/strong> = \u0111\u1ed9 nh\u1edbt \u0111\u1ed9ng h\u1ecdc c\u1ee7a n\u01b0\u1edbc (m\u00b2\/s)
\u03c1<\/strong> = m\u1eadt \u0111\u1ed9 n\u01b0\u1edbc (kg\/m\u00b3)
\u03bc<\/strong> = \u0111\u1ed9 nh\u1edbt \u0111\u1ed9ng l\u1ef1c h\u1ecdc c\u1ee7a n\u01b0\u1edbc (Pa\u00b7s)

\u0110\u1ed1i v\u1edbi m\u1ed9t tia n\u01b0\u1edbc c\u00f3 d\u1ea1ng g\u1ea7n nh\u01b0 h\u00ecnh tr\u00f2n, \u0111\u01b0\u1eddng k\u00ednh \u0111\u1ea7u ra danh ngh\u0129a c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng l\u00e0m \u0111\u01b0\u1eddng k\u00ednh \u0111\u1eb7c tr\u01b0ng cho vi\u1ec7c t\u00ednh to\u00e1n s\u01a1 b\u1ed9.

\u1ede 20\u00b0C, \u0111\u1ed9 nh\u1edbt \u0111\u1ed9ng h\u1ecdc c\u1ee7a n\u01b0\u1edbc x\u1ea5p x\u1ec9:

\u03bd = 1.004 \u00d7 10\u207b\u2076 m\u00b2\/s<\/strong>

Khi s\u1eed d\u1ee5ng ph\u01b0\u01a1ng tr\u00ecnh n\u00e0y, t\u1ea5t c\u1ea3 c\u00e1c \u0111\u1ea1i l\u01b0\u1ee3ng ph\u1ea3i c\u00f3 \u0111\u01a1n v\u1ecb nh\u1ea5t qu\u00e1n.

M\u1ed9t \u0111i\u1ec3m kh\u00e1c bi\u1ec7t quan tr\u1ecdng l\u00e0 \u0110\u01b0\u1eddng k\u00ednh k\u1ebft n\u1ed1i t\u1ea1i \u0111\u1ea7u v\u00e0o c\u1ee7a v\u00f2i phun kh\u00f4ng nh\u1ea5t thi\u1ebft ph\u1ea3i b\u1eb1ng \u0111\u01b0\u1eddng k\u00ednh t\u1ea1i \u0111\u1ea7u ra c\u1ee7a tia phun.<\/strong>Vi\u1ec7c s\u1eed d\u1ee5ng k\u1ebft n\u1ed1i \u0111\u1ea7u v\u00e0o DN40 cho m\u1ed9t v\u00f2i phun c\u00f3 \u0111\u1ea7u ra 14 mm s\u1ebd d\u1eabn \u0111\u1ebfn \u01b0\u1edbc t\u00ednh kh\u00f4ng ch\u00ednh x\u00e1c v\u1ec1 s\u1ed1 Reynolds t\u1ea1i \u0111\u1ea7u ra.<\/p><\/div><\/div><\/div>\n\n\n\n

\"Technical<\/figure><\/div>\n\n\n\n

M\u1ed9t ph\u00e9p t\u00ednh th\u1ef1c t\u1ebf: V\u00f2i phun n\u01b0\u1edbc d\u1ea1ng tia 14 mm<\/h3><\/div>

H\u00e3y xem x\u00e9t m\u1ed9t v\u00f2i phun minh h\u1ecda ho\u1ea1t \u0111\u1ed9ng trong c\u00e1c \u0111i\u1ec1u ki\u1ec7n sau \u0111\u00e2y:<\/p><\/div><\/div><\/div>\n\n\n\n

Tham s\u1ed1<\/th>Gi\u00e1 tr\u1ecb<\/th><\/tr>
Nhi\u1ec7t \u0111\u1ed9 n\u01b0\u1edbc<\/td>20\u00b0C<\/td><\/tr>
\u0110\u01b0\u1eddng k\u00ednh \u0111\u1ea7u ra tia phun<\/td>14 mm (0.014 m)<\/td><\/tr>
V\u1eadn t\u1ed1c trung b\u00ecnh t\u1ea1i \u0111\u1ea7u ra<\/td>5.0 m\/s<\/td><\/tr>
\u0110\u1ed9 nh\u1edbt \u0111\u1ed9ng h\u1ecdc<\/td>1.004 \u00d7 10\u207b\u2076 m\u00b2\/s<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n
<\/div>

Thay c\u00e1c gi\u00e1 tr\u1ecb v\u00e0o:

Re = (5.0 \u00d7 0.014) \/ (1.004 \u00d7 10\u207b\u2076)<\/strong>

Re \u2248 69,700<\/strong>

\u0110\u1ed1i v\u1edbi m\u1ed9t c\u1eeda x\u1ea3 h\u00ecnh tr\u00f2n \u0111\u01a1n l\u1ebb \u0111\u01b0\u1ee3c l\u1ea5p \u0111\u1ea7y, l\u01b0u l\u01b0\u1ee3ng l\u00fd thuy\u1ebft t\u01b0\u01a1ng \u1ee9ng l\u00e0:

Q = (\u03c0D\u00b2 \/ 4) \u00d7 V<\/strong>

Q \u2248 2.77 m\u00b3\/h<\/strong>

V\u00ed d\u1ee5 n\u00e0y s\u1eed d\u1ee5ng c\u00e1c \u0111i\u1ec1u ki\u1ec7n v\u1eadn h\u00e0nh gi\u1ea3 \u0111\u1ecbnh nh\u1eb1m m\u1ee5c \u0111\u00edch minh h\u1ecda. \u0110\u00e2y kh\u00f4ng ph\u1ea3i l\u00e0 k\u1ebft qu\u1ea3 \u0111o l\u01b0\u1eddng hi\u1ec7u su\u1ea5t th\u1ef1c t\u1ebf c\u1ee7a m\u1ed9t v\u00f2i phun Huaxin c\u1ee5 th\u1ec3.
S\u1ed1 Reynolds \u0111\u01b0\u1ee3c t\u00ednh to\u00e1n n\u1eb1m \u1edf m\u1ee9c cao h\u01a1n nhi\u1ec1u so v\u1edbi ph\u1ea1m vi d\u00f2ng ch\u1ea3y t\u1ea7ng trong \u1ed1ng th\u00f4ng th\u01b0\u1eddng.

\u0110i\u1ec1u n\u00e0y c\u00f3 ngh\u0129a l\u00e0 n\u01b0\u1edbc ph\u1ea3i l\u1eadp t\u1ee9c chuy\u1ec3n th\u00e0nh d\u1ea1ng phun s\u01b0\u01a1ng ph\u1ea3i kh\u00f4ng?

Kh\u00f4ng h\u1eb3n v\u1eady.<\/strong>

Gi\u00e1 tr\u1ecb \u0111\u01b0\u1ee3c t\u00ednh to\u00e1n cho th\u1ea5y c\u01b0\u1eddng \u0111\u1ed9 t\u01b0\u01a1ng \u0111\u1ed1i c\u1ee7a c\u00e1c hi\u1ec7u \u1ee9ng qu\u00e1n t\u00ednh v\u00e0 hi\u1ec7u \u1ee9ng nh\u1edbt. B\u1ea3n th\u00e2n gi\u00e1 tr\u1ecb n\u00e0y kh\u00f4ng cho bi\u1ebft b\u1ec1 m\u1eb7t c\u1ee7a tia ch\u1ea5t l\u01b0u s\u1ebd tr\u00f4ng nh\u1eb5n m\u1ecbn \u0111\u1ebfn m\u1ee9c n\u00e0o, hay d\u00f2ng ch\u1ea5t l\u01b0u s\u1ebd \u0111i \u0111\u01b0\u1ee3c bao xa tr\u01b0\u1edbc khi tan r\u00e3.

Ph\u00e2n b\u1ed1 v\u1eadn t\u1ed1c ban \u0111\u1ea7u, c\u00e1c nhi\u1ec5u lo\u1ea1n b\u00ean trong, h\u00ecnh h\u1ecdc v\u00f2i phun v\u00e0 c\u00e1c \u0111i\u1ec1u ki\u1ec7n kh\u00f4ng kh\u00ed xung quanh c\u0169ng \u1ea3nh h\u01b0\u1edfng \u0111\u1ebfn k\u1ebft qu\u1ea3.<\/p><\/div><\/div><\/div>\n\n\n\t\t\t\t\t\n\t\t\t\t\t\t\t\t\t\t\t

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<\/div>\n\t\t\t\t\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t\t
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