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Q: L\u01b0u l\u01b0\u1ee3ng (m\u00b3\/s)<\/p>\n<\/li>\n
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K: H\u1ec7 s\u1ed1 l\u01b0u l\u01b0\u1ee3ng<\/p>\n<\/li>\n
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A: Di\u1ec7n t\u00edch ti\u1ebft di\u1ec7n (m\u00b2)<\/p>\n<\/li>\n
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\u0394P: Ch\u00eanh l\u1ec7ch \u00e1p su\u1ea5t (Pa)<\/p>\n<\/li>\n
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\u03c1: Kh\u1ed1i l\u01b0\u1ee3ng ri\u00eang (kg\/m\u00b3)<\/p>\n<\/li>\n<\/ul>\n
\u01afu \u0111i\u1ec3m<\/strong>: Chi ph\u00ed th\u1ea5p, \u0111\u01a1n gi\u1ea3n, ph\u00f9 h\u1ee3p v\u1edbi \u0111\u01b0\u1eddng \u1ed1ng l\u1edbn.<\/span>
\nNh\u01b0\u1ee3c \u0111i\u1ec3m<\/strong>: G\u00e2y t\u1ed5n th\u1ea5t \u00e1p su\u1ea5t, \u0111\u1ed9 ch\u00ednh x\u00e1c h\u1ea1n ch\u1ebf (\u00b11-2%).<\/span><\/p>\n<\/span>2. Nguy\u00ean L\u00fd \u0110o \u0110i\u1ec7n T\u1eeb (Electromagnetic)<\/span><\/h3>\nC\u01a1 s\u1edf l\u00fd thuy\u1ebft<\/strong>: D\u1ef1a tr\u00ean \u0111\u1ecbnh lu\u1eadt c\u1ea3m \u1ee9ng \u0111i\u1ec7n t\u1eeb Faraday. Khi ch\u1ea5t l\u1ecfng d\u1eabn \u0111i\u1ec7n chuy\u1ec3n \u0111\u1ed9ng qua t\u1eeb tr\u01b0\u1eddng, s\u1ebd sinh ra \u0111i\u1ec7n \u00e1p c\u1ea3m \u1ee9ng t\u1ef7 l\u1ec7 v\u1edbi v\u1eadn t\u1ed1c d\u00f2ng ch\u1ea3y.<\/span><\/p>\nC\u1ea5u t\u1ea1o<\/strong>:<\/p>\n\n- \n
\u1ed0ng \u0111o l\u00e0m t\u1eeb v\u1eadt li\u1ec7u kh\u00f4ng t\u1eeb t\u00ednh, l\u00f3t c\u00e1ch \u0111i\u1ec7n<\/p>\n<\/li>\n
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Cu\u1ed9n d\u00e2y t\u1eeb t\u1ea1o t\u1eeb tr\u01b0\u1eddng vu\u00f4ng g\u00f3c v\u1edbi d\u00f2ng ch\u1ea3y<\/p>\n<\/li>\n
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\u0110i\u1ec7n c\u1ef1c thu nh\u1eadn \u0111i\u1ec7n \u00e1p c\u1ea3m \u1ee9ng<\/p>\n<\/li>\n<\/ul>\n
C\u00f4ng th\u1ee9c<\/strong>:
\nU=B\u00d7L\u00d7v<\/span>U<\/span>=<\/span><\/span>B<\/span>\u00d7<\/span><\/span>L<\/span>\u00d7<\/span><\/span>v<\/span><\/span><\/span><\/span><\/p>\nTrong \u0111\u00f3:<\/p>\n
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U: \u0110i\u1ec7n \u00e1p c\u1ea3m \u1ee9ng (V)<\/p>\n<\/li>\n
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B: M\u1eadt \u0111\u1ed9 t\u1eeb tr\u01b0\u1eddng (T)<\/p>\n<\/li>\n
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L: Kho\u1ea3ng c\u00e1ch gi\u1eefa hai \u0111i\u1ec7n c\u1ef1c (m)<\/p>\n<\/li>\n
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v: V\u1eadn t\u1ed1c trung b\u00ecnh (m\/s)<\/p>\n<\/li>\n<\/ul>\n
\u01afu \u0111i\u1ec3m<\/strong>: \u0110\u1ed9 ch\u00ednh x\u00e1c cao (\u00b10.2-0.5%), kh\u00f4ng c\u1ea3n tr\u1edf d\u00f2ng ch\u1ea3y, \u0111o \u0111\u01b0\u1ee3c hai chi\u1ec1u, ph\u00f9 h\u1ee3p v\u1edbi ch\u1ea5t l\u1ecfng c\u00f3 t\u1ea1p ch\u1ea5t.<\/span>
\nNh\u01b0\u1ee3c \u0111i\u1ec3m<\/strong>: Ch\u1ec9 \u0111o \u0111\u01b0\u1ee3c ch\u1ea5t l\u1ecfng d\u1eabn \u0111i\u1ec7n, chi ph\u00ed cao.<\/span><\/p>\n<\/span>3. Nguy\u00ean L\u00fd \u0110o Vortex (Xo\u00e1y)<\/span><\/h3>\nC\u01a1 s\u1edf l\u00fd thuy\u1ebft<\/strong>: D\u1ef1a tr\u00ean hi\u1ec7u \u1ee9ng Karman – khi d\u00f2ng ch\u1ea3y g\u1eb7p v\u1eadt c\u1ea3n, s\u1ebd t\u1ea1o ra c\u00e1c xo\u00e1y lu\u00e2n phi\u00ean \u1edf ph\u00eda sau v\u1edbi t\u1ea7n s\u1ed1 t\u1ef7 l\u1ec7 v\u1edbi v\u1eadn t\u1ed1c d\u00f2ng ch\u1ea3y.<\/span><\/p>\nC\u01a1 ch\u1ebf ho\u1ea1t \u0111\u1ed9ng<\/strong>:<\/p>\n\n- \n
M\u1ed9t thanh ch\u1eafn (bluff body) \u0111\u01b0\u1ee3c \u0111\u1eb7t vu\u00f4ng g\u00f3c v\u1edbi d\u00f2ng ch\u1ea3y<\/p>\n<\/li>\n
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C\u00e1c xo\u00e1y Karman h\u00ecnh th\u00e0nh \u0111\u1ec1u \u0111\u1eb7n \u1edf ph\u00eda sau<\/p>\n<\/li>\n
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C\u1ea3m bi\u1ebfn \u0111o t\u1ea7n s\u1ed1 xo\u00e1y \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh l\u01b0u l\u01b0\u1ee3ng<\/p>\n<\/li>\n<\/ul>\n
C\u00f4ng th\u1ee9c<\/strong>:
\nf=St\u00d7vd<\/span>f<\/span>=<\/span><\/span>St<\/span>\u00d7<\/span><\/span>d<\/span><\/span><\/span>v<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/p>\nTrong \u0111\u00f3:<\/p>\n
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f: T\u1ea7n s\u1ed1 xo\u00e1y Karman (Hz)<\/p>\n<\/li>\n
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St: S\u1ed1 Strouhal (h\u1eb1ng s\u1ed1 \u2248 0.17)<\/p>\n<\/li>\n
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v: V\u1eadn t\u1ed1c d\u00f2ng ch\u1ea3y (m\/s)<\/p>\n<\/li>\n
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d: Chi\u1ec1u r\u1ed9ng thanh ch\u1eafn (m)<\/p>\n<\/li>\n<\/ul>\n
\u01afu \u0111i\u1ec3m<\/strong>: Kh\u00f4ng c\u00f3 b\u1ed9 ph\u1eadn chuy\u1ec3n \u0111\u1ed9ng, \u0111\u1ed9 ch\u00ednh x\u00e1c cao (<0.5%), \u0111o \u0111\u01b0\u1ee3c c\u1ea3 l\u1ecfng, kh\u00ed v\u00e0 h\u01a1i.<\/span>
\nNh\u01b0\u1ee3c \u0111i\u1ec3m<\/strong>: Nh\u1ea1y c\u1ea3m v\u1edbi rung \u0111\u1ed9ng, y\u00eau c\u1ea7u v\u1eadn t\u1ed1c d\u00f2ng ch\u1ea3y t\u1ed1i thi\u1ec3u.<\/span><\/p>\n<\/span>4. Nguy\u00ean L\u00fd \u0110o Turbine<\/span><\/h3>\nC\u01a1 s\u1edf l\u00fd thuy\u1ebft<\/strong>: S\u1eed d\u1ee5ng chuy\u1ec3n \u0111\u1ed9ng quay c\u1ee7a c\u00e1nh turbine trong d\u00f2ng ch\u1ea3y. T\u1ed1c \u0111\u1ed9 quay t\u1ef7 l\u1ec7 thu\u1eadn v\u1edbi v\u1eadn t\u1ed1c d\u00f2ng ch\u1ea3y.<\/span><\/p>\nC\u01a1 ch\u1ebf ho\u1ea1t \u0111\u1ed9ng<\/strong>:<\/p>\n\n- \n
D\u00f2ng ch\u1ea3y l\u00e0m quay c\u00e1nh turbine<\/p>\n<\/li>\n
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C\u1ea3m bi\u1ebfn t\u1eeb ho\u1eb7c quang h\u1ecdc \u0111o t\u1ed1c \u0111\u1ed9 quay<\/p>\n<\/li>\n
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Chuy\u1ec3n \u0111\u1ed5i th\u00e0nh t\u00edn hi\u1ec7u \u0111i\u1ec7n t\u1ef7 l\u1ec7 v\u1edbi l\u01b0u l\u01b0\u1ee3ng<\/p>\n<\/li>\n<\/ul>\n
\u01afu \u0111i\u1ec3m<\/strong>: \u0110\u1ed9 ch\u00ednh x\u00e1c cao (0.5-1%), ph\u1ea1m vi \u0111o r\u1ed9ng, ph\u00f9 h\u1ee3p v\u1edbi ch\u1ea5t l\u1ecfng s\u1ea1ch.<\/span>
\nNh\u01b0\u1ee3c \u0111i\u1ec3m<\/strong>: C\u00f3 b\u1ed9 ph\u1eadn chuy\u1ec3n \u0111\u1ed9ng, d\u1ec5 b\u1ecb t\u1eafc ngh\u1ebdn, kh\u00f4ng ph\u00f9 h\u1ee3p v\u1edbi ch\u1ea5t l\u1ecfng c\u00f3 t\u1ea1p ch\u1ea5t.<\/span><\/p>\n<\/span>5. Nguy\u00ean L\u00fd \u0110o Si\u00eau \u00c2m (Ultrasonic)<\/span><\/h3>\nC\u01a1 s\u1edf l\u00fd thuy\u1ebft<\/strong>: S\u1eed d\u1ee5ng s\u00f3ng si\u00eau \u00e2m \u0111\u1ec3 \u0111o v\u1eadn t\u1ed1c d\u00f2ng ch\u1ea3y d\u1ef1a tr\u00ean s\u1ef1 kh\u00e1c bi\u1ec7t th\u1eddi gian truy\u1ec1n s\u00f3ng theo v\u00e0 ng\u01b0\u1ee3c chi\u1ec1u d\u00f2ng ch\u1ea3y.<\/span><\/p>\nC\u00e1c lo\u1ea1i<\/strong>:<\/p>\n\n- \n
Transit-time<\/strong>: \u0110o ch\u00eanh l\u1ec7ch th\u1eddi gian truy\u1ec1n s\u00f3ng<\/p>\n<\/li>\n- \n
Doppler<\/strong>: D\u1ef1a tr\u00ean hi\u1ec7u \u1ee9ng Doppler khi s\u00f3ng ph\u1ea3n x\u1ea1 t\u1eeb c\u00e1c h\u1ea1t trong d\u00f2ng ch\u1ea3y<\/p>\n<\/li>\n<\/ul>\n\u01afu \u0111i\u1ec3m<\/strong>: Kh\u00f4ng x\u00e2m l\u1ea5n, kh\u00f4ng g\u00e2y t\u1ed5n th\u1ea5t \u00e1p su\u1ea5t, l\u1eafp \u0111\u1eb7t ngo\u00e0i \u0111\u01b0\u1eddng \u1ed1ng.<\/span>
\nNh\u01b0\u1ee3c \u0111i\u1ec3m<\/strong>: Nh\u1ea1y c\u1ea3m v\u1edbi nhi\u1ec5u, y\u00eau c\u1ea7u l\u1eafp \u0111\u1eb7t ch\u00ednh x\u00e1c.<\/span><\/p>\n<\/span>6. Nguy\u00ean L\u00fd \u0110o Coriolis<\/span><\/h3>\nC\u01a1 s\u1edf l\u00fd thuy\u1ebft<\/strong>: D\u1ef1a tr\u00ean l\u1ef1c Coriolis – khi ch\u1ea5t l\u1ecfng chuy\u1ec3n \u0111\u1ed9ng trong \u1ed1ng dao \u0111\u1ed9ng, s\u1ebd t\u1ea1o ra l\u1ef1c l\u00e0m \u1ed1ng b\u1ecb xo\u1eafn v\u1edbi m\u1ee9c \u0111\u1ed9 t\u1ef7 l\u1ec7 v\u1edbi l\u01b0u l\u01b0\u1ee3ng kh\u1ed1i l\u01b0\u1ee3ng.<\/span><\/p>\nC\u01a1 ch\u1ebf ho\u1ea1t \u0111\u1ed9ng<\/strong>:<\/p>\n\n- \n
Hai \u1ed1ng \u0111\u01b0\u1ee3c cho dao \u0111\u1ed9ng \u0111\u1ed1i pha<\/p>\n<\/li>\n
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Khi c\u00f3 d\u00f2ng ch\u1ea3y, c\u00e1c \u1ed1ng b\u1ecb xo\u1eafn<\/p>\n<\/li>\n
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C\u1ea3m bi\u1ebfn \u0111o \u0111\u1ed9 l\u1ec7ch pha \u0111\u1ec3 x\u00e1c \u0111\u1ecbnh l\u01b0u l\u01b0\u1ee3ng kh\u1ed1i l\u01b0\u1ee3ng<\/p>\n<\/li>\n<\/ul>\n
\u01afu \u0111i\u1ec3m<\/strong>: \u0110\u1ed9 ch\u00ednh x\u00e1c r\u1ea5t cao (<0.01%), \u0111o tr\u1ef1c ti\u1ebfp l\u01b0u l\u01b0\u1ee3ng kh\u1ed1i l\u01b0\u1ee3ng, \u0111o th\u00eam \u0111\u01b0\u1ee3c m\u1eadt \u0111\u1ed9.<\/span>
\nNh\u01b0\u1ee3c \u0111i\u1ec3m<\/strong>: Chi ph\u00ed cao nh\u1ea5t, k\u00edch th\u01b0\u1edbc l\u1edbn, nh\u1ea1y c\u1ea3m v\u1edbi rung \u0111\u1ed9ng.<\/span><\/p>\n<\/span>7. Nguy\u00ean L\u00fd \u0110o Gia Nhi\u1ec7t<\/span><\/h3>\nC\u01a1 s\u1edf l\u00fd thuy\u1ebft<\/strong>: \u0110o l\u01b0u l\u01b0\u1ee3ng d\u1ef1a tr\u00ean s\u1ef1 truy\u1ec1n nhi\u1ec7t. C\u00f3 hai ph\u01b0\u01a1ng ph\u00e1p ch\u00ednh:<\/p>\n\n- \n
\u0110\u1eb7t nhi\u1ec7t l\u01b0\u1ee3ng c\u1ed1 \u0111\u1ecbnh v\u00e0 \u0111o s\u1ef1 suy gi\u1ea3m nhi\u1ec7t \u0111\u1ed9<\/p>\n<\/li>\n
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Duy tr\u00ec ch\u00eanh l\u1ec7ch nhi\u1ec7t \u0111\u1ed9 kh\u00f4ng \u0111\u1ed5i v\u00e0 \u0111o c\u00f4ng su\u1ea5t c\u1ea7n thi\u1ebft<\/p>\n<\/li>\n<\/ul>\n
\u01afu \u0111i\u1ec3m<\/strong>: Ph\u00f9 h\u1ee3p v\u1edbi d\u1ea7u tu\u1ea7n ho\u00e0n, \u0111\u1ed9 nh\u1ea1y cao.<\/span>
\nNh\u01b0\u1ee3c \u0111i\u1ec3m<\/strong>: Ch\u1ec9 d\u00f9ng cho m\u1ed9t s\u1ed1 \u1ee9ng d\u1ee5ng \u0111\u1eb7c bi\u1ec7t.<\/span><\/p>\n<\/span>So S\u00e1nh C\u00e1c Ph\u01b0\u01a1ng Ph\u00e1p \u0110o L\u01b0u L\u01b0\u1ee3ng