![\"Chuy\u1ec3n](\"https:\/\/www.thermal-engineering.org\/wp-content\/uploads\/2024\/07\/chuyen_nhiet_trong_dong_chay_phan_tang.png\")
<\/p>\nChuy\u1ec3n nhi\u1ec7t trong d\u00f2ng ch\u1ea3y ph\u00e2n t\u1ea7ng: Gi\u1ea3i th\u00edch nguy\u00ean l\u00fd chuy\u1ec3n nhi\u1ec7t, \u1ee9ng d\u1ee5ng trong h\u1ec7 th\u1ed1ng l\u00e0m m\u00e1t v\u00e0 c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t n\u0103ng l\u01b0\u1ee3ng.<\/p>\n
<\/p>\n
\nChuy\u1ec3n nhi\u1ec7t l\u00e0 qu\u00e1 tr\u00ecnh li\u00ean quan \u0111\u1ebfn vi\u1ec7c truy\u1ec1n nhi\u1ec7t \u0111\u1ed9 t\u1eeb m\u1ed9t v\u1eadt th\u1ec3 n\u00e0y sang v\u1eadt th\u1ec3 kh\u00e1c. Trong l\u0129nh v\u1ef1c k\u1ef9 thu\u1eadt nhi\u1ec7t, d\u00f2ng ch\u1ea3y ph\u00e2n t\u1ea7ng l\u00e0 m\u1ed9t hi\u1ec7n t\u01b0\u1ee3ng quan tr\u1ecdng c\u1ea7n \u0111\u01b0\u1ee3c hi\u1ec3u r\u00f5 \u0111\u1ec3 t\u1ed1i \u01b0u h\u00f3a qu\u00e1 tr\u00ecnh truy\u1ec1n nhi\u1ec7t trong c\u00e1c h\u1ec7 th\u1ed1ng kh\u00e1c nhau. D\u00f2ng ch\u1ea3y ph\u00e2n t\u1ea7ng th\u01b0\u1eddng xu\u1ea5t hi\u1ec7n khi ch\u1ea5t l\u1ecfng ch\u1ea3y qua m\u1ed9t b\u1ec1 m\u1eb7t ho\u1eb7c m\u1ed9t \u1ed1ng v\u1edbi t\u1ed1c \u0111\u1ed9 th\u1ea5p. Trong b\u00e0i vi\u1ebft n\u00e0y, ch\u00fang ta s\u1ebd t\u00ecm hi\u1ec3u v\u1ec1 c\u01a1 ch\u1ebf chuy\u1ec3n nhi\u1ec7t trong d\u00f2ng ch\u1ea3y ph\u00e2n t\u1ea7ng.\n<\/p>\n
\nTrong d\u00f2ng ch\u1ea3y ph\u00e2n t\u1ea7ng, l\u1edbp ch\u1ea5t l\u1ecfng g\u1ea7n b\u1ec1 m\u1eb7t c\u1ee7a v\u1eadt th\u1ec3 s\u1ebd ch\u1ea3y m\u01b0\u1ee3t m\u00e0 v\u00e0 kh\u00f4ng b\u1ecb nhi\u1ec5u lo\u1ea1n. \u0110i\u1ec1u n\u00e0y d\u1eabn \u0111\u1ebfn m\u1ed9t gradient v\u1eadn t\u1ed1c, t\u1ee9c l\u00e0 v\u1eadn t\u1ed1c c\u1ee7a ch\u1ea5t l\u1ecfng s\u1ebd thay \u0111\u1ed5i t\u1eeb b\u1ec1 m\u1eb7t (v\u1eadn t\u1ed1c g\u1ea7n 0) \u0111\u1ebfn ph\u1ea7n gi\u1eefa c\u1ee7a d\u00f2ng ch\u1ea3y (v\u1eadn t\u1ed1c t\u1ed1i \u0111a).\n<\/p>\n
<\/u1><\/p>\n \nPh\u01b0\u01a1ng tr\u00ecnh n\u0103ng l\u01b0\u1ee3ng cho d\u00f2ng ch\u1ea3y ph\u00e2n t\u1ea7ng c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c m\u00f4 t\u1ea3 b\u1eb1ng ph\u01b0\u01a1ng tr\u00ecnh vi ph\u00e2n, d\u1ec5 hi\u1ec3u h\u01a1n khi th\u1ef1c hi\u1ec7n trong \u0111i\u1ec1u ki\u1ec7n \u1ed5n \u0111\u1ecbnh. Ph\u01b0\u01a1ng tr\u00ecnh n\u0103ng l\u01b0\u1ee3ng kh\u00f4ng n\u00e9n \u0111\u01b0\u1ee3c th\u1ec3 hi\u1ec7n nh\u01b0 sau:\n<\/p>\n \n\\[ <\/u1><\/p>\n \nS\u1ed1 Prandtl (Pr) l\u00e0 m\u1ed9t \u0111\u1ea1i l\u01b0\u1ee3ng kh\u00f4ng th\u1ee9 nguy\u00ean quan tr\u1ecdng trong vi\u1ec7c m\u00f4 t\u1ea3 m\u1ed1i quan h\u1ec7 gi\u1eefa d\u1eabn nhi\u1ec7t v\u00e0 \u0111\u1ed1i l\u01b0u trong ch\u1ea5t l\u1ecfng. S\u1ed1 Pr \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a nh\u01b0 sau:\n<\/p>\n \n\\[ <\/u1><\/p>\n \nKhi s\u1ed1 Prandtl nh\u1ecf (v\u00ed d\u1ee5 nh\u01b0 \u0111\u1ed1i v\u1edbi kh\u00ed), d\u1eabn nhi\u1ec7t chi\u1ebfm \u01b0u th\u1ebf, trong khi \u0111\u1ed1i v\u1edbi ch\u1ea5t l\u1ecfng c\u00f3 s\u1ed1 Prandtl l\u1edbn (v\u00ed d\u1ee5 nh\u01b0 d\u1ea7u), \u0111\u1ed1i l\u01b0u chi\u1ebfm \u01b0u th\u1ebf.\n<\/p>\n \nTrong k\u1ef9 thu\u1eadt nhi\u1ec7t, hi\u1ec3u bi\u1ebft v\u1ec1 chuy\u1ec3n nhi\u1ec7t trong d\u00f2ng ch\u1ea3y ph\u00e2n t\u1ea7ng gi\u00fap c\u1ea3i ti\u1ebfn hi\u1ec7u su\u1ea5t c\u1ee7a c\u00e1c thi\u1ebft b\u1ecb trao \u0111\u1ed5i nhi\u1ec7t nh\u01b0 b\u1ed9 trao \u0111\u1ed5i nhi\u1ec7t, n\u1ed3i h\u01a1i, v\u00e0 h\u1ec7 th\u1ed1ng l\u00e0m m\u00e1t \u00f4 t\u00f4. Qua vi\u1ec7c t\u1ed1i \u01b0u h\u00f3a thi\u1ebft k\u1ebf c\u00e1c thi\u1ebft b\u1ecb n\u00e0y, hi\u1ec7u su\u1ea5t n\u0103ng l\u01b0\u1ee3ng c\u00f3 th\u1ec3 \u0111\u01b0\u1ee3c n\u00e2ng cao, ti\u1ebft ki\u1ec7m chi ph\u00ed v\u00e0 gi\u1ea3m thi\u1ec3u t\u00e1c \u0111\u1ed9ng m\u00f4i tr\u01b0\u1eddng.\n<\/p>\n <\/u1><\/p>\n \nVi\u1ec7c hi\u1ec3u r\u00f5 v\u00e0 \u1ee9ng d\u1ee5ng c\u00e1c nguy\u00ean l\u00fd c\u1ee7a chuy\u1ec3n nhi\u1ec7t trong d\u00f2ng ch\u1ea3y ph\u00e2n t\u1ea7ng l\u00e0 m\u1ed9t y\u1ebfu t\u1ed1 thi\u1ebft y\u1ebfu trong vi\u1ec7c c\u1ea3i ti\u1ebfn hi\u1ec7u qu\u1ea3 n\u0103ng l\u01b0\u1ee3ng v\u00e0 b\u1ea3o v\u1ec7 m\u00f4i tr\u01b0\u1eddng.<\/p>\n","protected":false},"excerpt":{"rendered":" Chuy\u1ec3n nhi\u1ec7t trong d\u00f2ng ch\u1ea3y ph\u00e2n t\u1ea7ng: Gi\u1ea3i th\u00edch nguy\u00ean l\u00fd chuy\u1ec3n nhi\u1ec7t, \u1ee9ng d\u1ee5ng trong h\u1ec7 th\u1ed1ng l\u00e0m m\u00e1t v\u00e0 c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t n\u0103ng l\u01b0\u1ee3ng.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":[],"categories":[132],"tags":[],"yoast_head":"\n
\n\\frac{d}{dx} (k \\frac{dT}{dy}) = 0
\n\\]\n
\ntrong \u0111\u00f3:\n<\/p>\nPh\u01b0\u01a1ng Tr\u00ecnh Prandtl<\/h2>\n
\nPr = \\frac{\\nu}{\\alpha}
\n\\]\n
\ntrong \u0111\u00f3:\n<\/p>\n\u1ee8ng D\u1ee5ng Th\u1ef1c Ti\u1ec5n<\/h2>\n