![\"Hi\u1ec3u](\"https:\/\/www.thermal-engineering.org\/wp-content\/uploads\/2024\/07\/hieu_ve_chuyen_giao_dong_luong_chat_long.png\")
<\/p>\nHi\u1ec3u v\u1ec1 Chuy\u1ec3n giao \u0110\u1ed9ng l\u01b0\u1ee3ng Ch\u1ea5t l\u1ecfng: Gi\u1ea3i th\u00edch nguy\u00ean l\u00fd, \u1ee9ng d\u1ee5ng trong thermal engineering, v\u00e0 t\u1ea7m quan tr\u1ecdng c\u1ee7a vi\u1ec7c \u0111i\u1ec1u khi\u1ec3n d\u00f2ng ch\u1ea3y ch\u1ea5t l\u1ecfng.<\/p>\n
<\/p>\n
Chuy\u1ec3n giao \u0111\u1ed9ng l\u01b0\u1ee3ng l\u00e0 m\u1ed9t kh\u00e1i ni\u1ec7m quan tr\u1ecdng trong ng\u00e0nh k\u1ef9 thu\u1eadt nhi\u1ec7t v\u00e0 c\u01a1 h\u1ecdc ch\u1ea5t l\u1ecfng. N\u00f3 li\u00ean quan \u0111\u1ebfn vi\u1ec7c l\u1ef1c t\u00e1c \u0111\u1ed9ng l\u00ean ch\u1ea5t l\u1ecfng l\u00e0m thay \u0111\u1ed5i v\u1eadn t\u1ed1c v\u00e0 h\u01b0\u1edbng di chuy\u1ec3n c\u1ee7a ch\u1ea5t l\u1ecfng \u0111\u00f3. \u0110\u1ed9ng l\u01b0\u1ee3ng (momentum) \u0111\u01b0\u1ee3c \u0111\u1ecbnh ngh\u0129a l\u00e0 t\u00edch c\u1ee7a kh\u1ed1i l\u01b0\u1ee3ng v\u00e0 v\u1eadn t\u1ed1c c\u1ee7a m\u1ed9t \u0111\u1ed1i t\u01b0\u1ee3ng. Trong b\u00e0i vi\u1ebft n\u00e0y, ch\u00fang ta s\u1ebd t\u00ecm hi\u1ec3u v\u1ec1 c\u01a1 b\u1ea3n c\u1ee7a chuy\u1ec3n giao \u0111\u1ed9ng l\u01b0\u1ee3ng trong ch\u1ea5t l\u1ecfng v\u00e0 c\u00e1ch n\u00f3 \u00e1p d\u1ee5ng trong th\u1ef1c ti\u1ec5n.<\/p>\n
Khi m\u1ed9t ch\u1ea5t l\u1ecfng di chuy\u1ec3n, n\u00f3 mang theo \u0111\u1ed9ng l\u01b0\u1ee3ng. \u0110\u1ec3 hi\u1ec3u s\u1ef1 thay \u0111\u1ed5i \u0111\u1ed9ng l\u01b0\u1ee3ng, ta s\u1eed d\u1ee5ng ph\u01b0\u01a1ng tr\u00ecnh vi ph\u00e2n c\u1ee7a Navier-Stokes, c\u00f4ng c\u1ee5 c\u01a1 b\u1ea3n nh\u1ea5t trong c\u01a1 h\u1ecdc ch\u1ea5t l\u1ecfng, \u0111\u01b0\u1ee3c bi\u1ec3u di\u1ec5n nh\u01b0 sau:<\/p>\n
\\[ \\rho \\left( \\frac{\\partial \\mathbf{u}}{\\partial t} + \\mathbf{u} \\cdot \\nabla \\mathbf{u} \\right) = -\\nabla p + \\mu \\nabla^2 \\mathbf{u} + \\mathbf{f} \\]\n
Trong \u0111\u00f3:<\/p>\n
Ph\u01b0\u01a1ng tr\u00ecnh n\u00e0y m\u00f4 t\u1ea3 s\u1ef1 c\u00e2n b\u1eb1ng gi\u1eefa l\u1ef1c \u00e1p su\u1ea5t, l\u1ef1c \u0111\u1ed9 nh\u1edbt v\u00e0 l\u1ef1c ngo\u1ea1i vi trong ch\u1ea5t l\u1ecfng.<\/p>\n
Khi ch\u1ea5t l\u1ecfng ch\u1ea3y qua b\u1ec1 m\u1eb7t, c\u00f3 m\u1ed9t v\u00f9ng m\u1ecfng g\u1ea7n b\u1ec1 m\u1eb7t g\u1ecdi l\u00e0 l\u1edbp bi\u00ean (boundary layer) n\u01a1i m\u00e0 v\u1eadn t\u1ed1c c\u1ee7a ch\u1ea5t l\u1ecfng thay \u0111\u1ed5i nhanh ch\u00f3ng t\u1eeb kh\u00f4ng v\u1ec1 \u0111\u1ebfn v\u1eadn t\u1ed1c d\u00f2ng ch\u00ednh. Hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y c\u1ef1c k\u1ef3 quan tr\u1ecdng trong vi\u1ec7c thi\u1ebft k\u1ebf c\u00e1nh qu\u1ea1t, \u1ed1ng d\u1eabn v\u00e0 nhi\u1ec1u \u1ee9ng d\u1ee5ng kh\u00e1c.<\/p>\n
Ch\u1ea3y nhi\u1ec5u lo\u1ea1n (turbulent flow) l\u00e0 m\u1ed9t d\u1ea1ng ch\u1ea3y ph\u1ee9c t\u1ea1p h\u01a1n, trong \u0111\u00f3 c\u00e1c y\u1ebfu t\u1ed1 nh\u01b0 v\u1eadn t\u1ed1c v\u00e0 \u00e1p su\u1ea5t thay \u0111\u1ed5i kh\u00f4ng th\u1ec3 d\u1ef1 \u0111o\u00e1n \u0111\u01b0\u1ee3c. Ch\u1ea3y nhi\u1ec5u lo\u1ea1n th\u01b0\u1eddng x\u1ea3y ra \u1edf v\u1eadn t\u1ed1c cao ho\u1eb7c khi ch\u1ea5t l\u1ecfng ch\u1ea3y qua c\u00e1c b\u1ec1 m\u1eb7t g\u1eadp gh\u1ec1nh. \u0110\u1ec3 m\u00f4 t\u1ea3 hi\u1ec7n t\u01b0\u1ee3ng n\u00e0y, ch\u00fang ta th\u01b0\u1eddng s\u1eed d\u1ee5ng m\u00f4 h\u00ecnh th\u1ed1ng k\u00ea ho\u1eb7c ph\u01b0\u01a1ng tr\u00ecnh vi ph\u00e2n trung b\u00ecnh.<\/p>\n
Chuy\u1ec3n giao \u0111\u1ed9ng l\u01b0\u1ee3ng ch\u1ea5t l\u1ecfng \u0111\u01b0\u1ee3c \u00e1p d\u1ee5ng r\u1ed9ng r\u00e3i trong \u0111\u1eddi s\u1ed1ng h\u00e0ng ng\u00e0y v\u00e0 c\u00f4ng nghi\u1ec7p:<\/p>\n
Chuy\u1ec3n giao \u0111\u1ed9ng l\u01b0\u1ee3ng trong ch\u1ea5t l\u1ecfng l\u00e0 m\u1ed9t l\u0129nh v\u1ef1c ph\u1ee9c t\u1ea1p nh\u01b0ng r\u1ea5t th\u00fa v\u1ecb v\u00e0 quan tr\u1ecdng trong k\u1ef9 thu\u1eadt nhi\u1ec7t. Hi\u1ec3u r\u00f5 v\u1ec1 c\u00e1c nguy\u00ean l\u00fd v\u00e0 \u1ee9ng d\u1ee5ng c\u1ee7a n\u00f3 gi\u00fap c\u00e1c k\u1ef9 s\u01b0 v\u00e0 nh\u00e0 khoa h\u1ecdc thi\u1ebft k\u1ebf c\u00e1c h\u1ec7 th\u1ed1ng hi\u1ec7u qu\u1ea3 h\u01a1n, c\u1ea3i thi\u1ec7n hi\u1ec7u su\u1ea5t v\u00e0 ti\u1ebft ki\u1ec7m n\u0103ng l\u01b0\u1ee3ng.<\/p>\n","protected":false},"excerpt":{"rendered":"
Hi\u1ec3u v\u1ec1 Chuy\u1ec3n giao \u0110\u1ed9ng l\u01b0\u1ee3ng Ch\u1ea5t l\u1ecfng: Gi\u1ea3i th\u00edch nguy\u00ean l\u00fd, \u1ee9ng d\u1ee5ng trong thermal engineering, v\u00e0 t\u1ea7m quan tr\u1ecdng c\u1ee7a vi\u1ec7c \u0111i\u1ec1u khi\u1ec3n d\u00f2ng ch\u1ea3y ch\u1ea5t l\u1ecfng.<\/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