{"id":230,"date":"2020-12-21T01:33:48","date_gmt":"2020-12-20T18:33:48","guid":{"rendered":"https:\/\/cdha.edu.vn\/cdha\/?p=230"},"modified":"2020-12-21T12:35:41","modified_gmt":"2020-12-21T05:35:41","slug":"su-phuc-hoi-ap-luc-pressure-recovery","status":"publish","type":"post","link":"https:\/\/cdha.edu.vn\/cdha\/su-phuc-hoi-ap-luc-pressure-recovery\/","title":{"rendered":"S\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c &#8211; Pressure recovery"},"content":{"rendered":"\n<p style=\"text-align: justify;\">Trong c\u00e1c t\u00e0i li\u1ec7u si\u00eau \u00e2m tim th\u01b0\u1eddng nh\u1eafc \u0111\u1ebfn kh\u00e1i ni\u1ec7u &#8220;S\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c&#8221;, \u0111\u1eb7c bi\u1ec7t trong h\u1eb9p van \u0111\u1ed9ng m\u1ea1ch ch\u1ee7. V\u1eady s\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c l\u00e0 g\u00ec?<\/p>\n<p style=\"text-align: justify;\">\u0110\u1ecbnh lu\u1eadt Bernoulli ph\u00e1t bi\u1ec3u r\u1eb1ng, khi m\u1ed9t d\u00f2ng ch\u1ea3y (kh\u00ed, n\u01b0\u1edbc, m\u00e1u, vv) di chuy\u1ec3n qua m\u1ed9t \u1ed1ng d\u1eabn, v\u1eadn t\u1ed1c c\u00e0ng cao th\u00ec \u00e1p l\u1ef1c n\u00f3 t\u00e1c \u0111\u1ed9ng l\u00ean th\u00e0nh \u1ed1ng c\u00e0ng gi\u1ea3m. \u0110\u1ed9 t\u0103ng v\u1eadn t\u1ed1c b\u1eb1ng \u0111\u1ed9 gi\u1ea3m \u00e1p l\u1ef1c.<\/p>\n<p><img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/drsvenkatesan.files.wordpress.com\/2013\/11\/3zsiey3.gif?w=493\" \/><\/p>\n<p style=\"text-align: justify;\">Trong h\u00ecnh minh h\u1ecda nguy\u00ean l\u00fd ho\u1ea1t \u0111\u1ed9ng c\u1ee7a c\u00e1nh m\u00e1y bay \u1edf tr\u00ean, s\u1ef1 b\u1ed1 tr\u00ed h\u01b0\u1edbng c\u00e1nh m\u00e1y bay l\u00e0m cho d\u00f2ng kh\u00f4ng kh\u00ed \u1edf b\u00ean d\u01b0\u1edbi c\u00e1nh b\u1ecb ch\u1eb7n l\u1ea1i, di chuy\u1ec3n ch\u1eadm l\u1ea1i -&gt; \u00e1p l\u1ef1c t\u00e1c \u0111\u1ed9ng l\u00ean m\u1eb7t d\u01b0\u1edbi c\u00e1nh cao. S\u1ef1 b\u1ed1 tr\u00ed n\u00e0y c\u0169ng l\u00e0m cho d\u00f2ng kh\u00f4ng kh\u00ed \u1edf tr\u00ean c\u00e1nh m\u00e1y bay di chuy\u1ec3n nhanh h\u01a1n, \u00e1p l\u1ef1c \u1edf ph\u00eda tr\u00ean c\u00e1nh m\u00e1y bay gi\u1ea3m. L\u00fac n\u00e0y xu\u1ea5t hi\u1ec7n s\u1ef1 ch\u00eanh l\u1ec7ch \u00e1p l\u1ef1c gi\u1eefa m\u1eb7t d\u01b0\u1edbi v\u00e0 m\u1eb7t tr\u00ean c\u00e1nh m\u00e1y bay, do \u0111\u00f3 h\u00ecnh th\u00e0nh l\u1ef1c \u0111\u1ea9y n\u00e2ng c\u00e1nh m\u00e1y bay t\u1eeb d\u01b0\u1edbi l\u00ean tr\u00ean<\/p>\n<p>B\u00e2y gi\u1edd h\u00e3y ph\u00e2n t\u00edch nh\u1eefng g\u00ec x\u1ea3y ra trong van \u0111\u1ed9ng m\u1ea1ch ch\u1ee7.\u00a0<\/p>\n<p><img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/cdha.edu.vn\/cdha\/wp-content\/uploads\/2020\/12\/image-2.png\" alt=\"H\u00ecnh \u1ea3nh n\u00e0y ch\u01b0a c\u00f3 thu\u1ed9c t\u00ednh alt; t\u00ean t\u1ec7p c\u1ee7a n\u00f3 l\u00e0 image-2.png\" \/><\/p>\n<p style=\"text-align: justify;\">T\u1ea1i bu\u1ed3ng t\u1ed1ng th\u1ea5t tr\u00e1i, d\u00f2ng ch\u1ea3y c\u00f3 v\u1eadn t\u1ed1c ch\u1eadm, g\u00e2y ra m\u1ed9t \u00e1p su\u1ea5t l\u1edbn l\u00e0 P<sub>LV<\/sub>. T\u1ea1i van \u0111\u1ed9ng m\u1ea1ch ch\u1ee7, \u0111\u01b0\u1eddng k\u00ednh nh\u1ecf l\u1ea1i, d\u00f2ng ch\u1ea3y t\u0103ng v\u1eadn t\u1ed1c l\u00ean, \u00e1p l\u1ef1c m\u00e0 n\u00f3 g\u00e2y ra gi\u1ea3m xu\u1ed1ng, c\u00f2n P<sub>VC<\/sub>. \u0110\u1ed9 ch\u00eanh \u00e1p t\u1ea1i van \u0110MC v\u00e0 bu\u1ed3ng t\u1ed1ng l\u00fac n\u00e0y l\u00e0 PG<sub>max<\/sub>.<\/p>\n<p style=\"text-align: justify;\">Khi d\u00f2ng ch\u1ea3y \u0111i qua ch\u1ed7 h\u1eb9p, n\u00f3 v\u00e0o \u0111\u1ed9ng m\u1ea1ch ch\u1ee7, k\u00edch th\u01b0\u1edbc l\u1edbn, v\u1eadn t\u1ed1c gi\u1ea3m l\u1ea1i -&gt; \u00e1p l\u1ef1c l\u1ea1i t\u0103ng l\u00ean. S\u1ef1 t\u0103ng \u00e1p l\u1ef1c l\u1ea1i n\u00e0y g\u1ecdi l\u00e0 s\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c. \u0110\u1ed9 ch\u00eanh l\u1ec7ch \u00e1p l\u1ef1c t\u1ea1i l\u00f2ng \u0111\u1ed9ng m\u1ea1ch ch\u1ee7 v\u00e0 t\u1ea1i bu\u1ed3ng t\u1ed1ng th\u1ea5t tr\u00e1i l\u00fac n\u00e0y l\u00e0 PG<sub>net<\/sub>.<\/p>\n<p style=\"text-align: justify;\">Ti\u1ebfp t\u1ee5c xem x\u00e9t m\u1ed9t v\u1ea5n \u0111\u1ec1 kh\u00e1c, \u0111\u00f3 l\u00e0 k\u00edch th\u01b0\u1edbc c\u1ee7a \u0111\u1ed9ng m\u1ea1ch ch\u1ee7 \u1ea3nh h\u01b0\u1edfng th\u1ebf n\u00e0o \u0111\u1ebfn s\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c.<\/p>\n<p><img decoding=\"async\" class=\"aligncenter\" src=\"https:\/\/cdha.edu.vn\/cdha\/wp-content\/uploads\/2020\/12\/image-3.png\" alt=\"H\u00ecnh \u1ea3nh n\u00e0y ch\u01b0a c\u00f3 thu\u1ed9c t\u00ednh alt; t\u00ean t\u1ec7p c\u1ee7a n\u00f3 l\u00e0 image-3.png\" \/><\/p>\n<p style=\"text-align: justify;\">Trong h\u00ecnh A, v\u1edbi m\u1ed9t \u0111\u1ed9ng m\u1ea1ch ch\u1ee7 d\u00e3n, ng\u01b0\u1eddi ta th\u1ea5y r\u1eb1ng khi d\u00f2ng ch\u1ea3y qua kh\u1ecfi l\u1ed7 van, v\u00e0o l\u00f2ng \u0111\u1ed9ng m\u1ea1ch ch\u1ee7 d\u00e3n, \u00e1p l\u1ef1c kh\u00f4ng t\u0103ng l\u00ean nhi\u1ec1u. \u0110\u1ed9 ch\u00eanh \u00e1p t\u1ea1i l\u00f2ng m\u1ea1ch (PG<sub>net<\/sub>) kh\u00f4ng kh\u00e1c nhi\u1ec1u \u0111\u1ed9 ch\u00eanh \u00e1p t\u1ea1i van \u0110MC (PG<sub>max<\/sub>). C\u1ea7n l\u01b0u \u00fd l\u00e0 PG<sub>net<\/sub> \u0111\u01b0\u1ee3c \u0111o b\u1eb1ng th\u00f4ng tim, c\u00f2n PG<sub>max<\/sub> \u0111\u01b0\u1ee3c \u0111o b\u1eb1ng si\u00eau \u00e2m Doppler.<\/p>\n<p style=\"text-align: justify;\">Trong h\u00ecnh B, v\u1edbi m\u1ed9t \u0111\u1ed9ng m\u1ea1ch ch\u1ee7 h\u1eb9p, ng\u01b0\u1eddi ta th\u1ea5y r\u1eb1ng khi d\u00f2ng ch\u1ea3y qua kh\u1ecfi l\u1ed7 van, n\u00f3 \u0111i v\u00e0o l\u00f2ng m\u1ea1ch, \u00e1p l\u1ef1c t\u0103ng l\u00ean nhi\u1ec1u, \u0111\u1ed9 ch\u00eanh \u00e1p t\u1ea1i l\u00f2ng m\u1ea1ch (PG<sub>net<\/sub>) kh\u00e1c bi\u1ec7t nhi\u1ec1u so v\u1edbi \u0111\u1ed9 ch\u00eanh \u00e1p t\u1ea1i van \u0110MC (PG<sub>max<\/sub>).<\/p>\n<p style=\"text-align: justify;\">L\u00fd gi\u1ea3i hi\u1ec7n t\u01b0\u1ee3ng trong h\u00ecnh B kh\u00e1 d\u1ec5, gi\u1ed1ng nh\u01b0 nguy\u00ean t\u1eafc Bernoulli \u0111\u01b0\u1ee3c n\u00f3i \u1edf tr\u00ean, v\u00ec l\u00f2ng m\u1ea1ch c\u00f3 \u0111\u01b0\u1eddng k\u00ednh l\u1edbn h\u01a1n l\u1ed7 van, n\u00ean d\u00f2ng ch\u1ea3y \u0111i t\u1eeb l\u1ed7 van v\u00e0o l\u00f2ng m\u1ea1ch s\u1ebd gi\u1ea3m b\u1ecb v\u1eadn t\u1ed1c, v\u00e0 \u00e1p l\u1ef1c n\u00f3 g\u00e2y ra t\u0103ng l\u00ean. V\u1eady t\u1ea1i sao trong h\u00ecnh A, khi l\u00f2ng m\u1ea1ch d\u00e3n to h\u01a1n, l\u1ebd ra v\u1eadn t\u1ed1c ph\u1ea3i gi\u1ea3m nhi\u1ec1u h\u01a1n, \u00e1p l\u1ef1c ph\u1ea3i t\u0103ng l\u00ean nhi\u1ec1u n\u1eefa, nh\u01b0ng th\u1ef1c t\u1ebf \u00e1p l\u1ef1c l\u1ea1i t\u0103ng l\u00ean kh\u00f4ng \u0111\u00e1ng k\u1ec3. V\u00ec sao l\u1ea1i c\u00f3 s\u1ef1 m\u00e2u thu\u1eabn n\u00e0y?<\/p>\n<p style=\"text-align: justify;\">H\u00e3y xem x\u00e9t v\u1ea5n \u0111\u1ec1 d\u01b0\u1edbi g\u00f3c nh\u00ecn n\u0103ng l\u01b0\u1ee3ng<\/p>\n<p style=\"text-align: justify;\">M\u1ed9t kh\u1ed1i ch\u1ea5t l\u1ecfng di chuy\u1ec3n mang trong n\u00f3 3 lo\u1ea1i n\u0103ng l\u01b0\u1ee3ng, \u0111\u00f3 l\u00e0 \u0111\u1ed9ng n\u0103ng (v\u1eadn t\u1ed1c &#8211; V), th\u1ebf n\u0103ng (\u00e1p l\u1ef1c &#8211; P) v\u00e0 nhi\u1ec7t n\u0103ng (T). T\u1ed5ng c\u1ee7a 3 lo\u1ea1i n\u0103ng l\u01b0\u1ee3ng n\u00e0y l\u00e0 c\u1ed1 \u0111\u1ecbnh.<\/p>\n<p style=\"text-align: center;\">E = V + P + T<\/p>\n<p style=\"text-align: justify;\">N\u1ebfu c\u00f3 th\u00e0nh ph\u1ea7n n\u00e0y gia t\u0103ng th\u00ec 2 th\u00e0nh ph\u1ea7n kia s\u1ebd b\u1ecb gi\u1ea3m xu\u1ed1ng. V\u00ed d\u1ee5: khi v\u1eadn t\u1ed1c t\u0103ng l\u00ean do d\u00f2ng ch\u1ea3y qua ch\u1ed7 h\u1eb9p, t\u1ee9c l\u00e0 \u0111\u1ed9ng n\u0103ng t\u0103ng l\u00ean, th\u00ec \u00e1p l\u1ef1c s\u1ebd b\u1ecb gi\u1ea3m xu\u1ed1ng, t\u1ee9c l\u00e0 th\u1ebf n\u0103ng gi\u1ea3m xu\u1ed1ng. Khi d\u00f2ng ch\u1ea3y \u0111i v\u00e0o l\u00f2ng m\u1ea1ch, v\u00ec l\u00f2ng m\u1ea1ch l\u1edbn h\u01a1n l\u1ed7 van, n\u00ean v\u1eadn t\u1ed1c b\u1ecb gi\u1ea3m, \u0111\u1ed9ng n\u0103ng gi\u1ea3m, l\u00fac n\u00e0y th\u1ebf n\u0103ng s\u1ebd t\u0103ng l\u00ean, t\u1ee9c l\u00e0 \u00e1p l\u1ef1c t\u0103ng l\u00ean. \u0110\u00e2y g\u1ecdi l\u00e0 s\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c &#8211; pressure recovery.<\/p>\n<p style=\"text-align: justify;\">Khi ch\u1ea5t l\u1ecfng \u0111\u1ed9t ng\u1ed9t \u0111i v\u00e0o m\u1ed9t \u0111o\u1ea1n m\u1ea1ch c\u00f3 k\u00edch th\u01b0\u1edbc l\u1edbn ngay sau l\u1ed7 van (h\u00ecnh A \u1edf tr\u00ean), s\u1ebd x\u1ea3y ra t\u00ecnh tr\u1ea1ng h\u1ed7n lo\u1ea1n (s\u1ef1 h\u1ed7n lo\u1ea1n t\u1ee9c l\u00e0 gia t\u0103ng nhi\u1ec7t), l\u00fac n\u00e0y v\u1eadn t\u1ed1c gi\u1ea3m nh\u01b0ng nhi\u1ec7t n\u0103ng t\u0103ng -&gt; th\u1ebf n\u0103ng kh\u00f4ng t\u0103ng \u0111\u01b0\u1ee3c, s\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p su\u1ea5t kh\u00f4ng x\u1ea3y ra ho\u1eb7c x\u1ea3y ra \u00edt.\u00a0<\/p>\n<p style=\"text-align: justify;\">Khi ch\u1ea5t l\u1ecfng \u0111i v\u00e0o \u0111o\u1ea1n m\u1ea1ch c\u00f3 k\u00edch th\u01b0\u1edbc nh\u1ecf (h\u1eb9p) sau l\u1ed7 van, s\u1ef1 h\u1ed7n lo\u1ea1n x\u1ea3y ra \u00edt, nhi\u1ec7t n\u0103ng kh\u00f4ng t\u0103ng nhi\u1ec1u, ph\u1ea7n l\u1edbn \u0111\u1ed9ng n\u0103ng chuy\u1ec3n th\u00e0nh th\u1ebf n\u0103ng -&gt; \u00e1p l\u1ef1c \u0111\u01b0\u1ee3c gia t\u0103ng nhi\u1ec1u.\u00a0<\/p>\n<p style=\"text-align: justify;\">Nh\u01b0 v\u1eady l\u00f2ng m\u1ea1ch c\u00e0ng b\u1ecb d\u00e3n l\u1edbn, s\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c c\u00e0ng \u00edt, t\u1ee9c l\u00e0 \u0111\u1ed9 ch\u00eanh \u00e1p \u0111o b\u1eb1ng si\u00eau \u00e2m doppler kh\u00f4ng kh\u00e1c nhi\u1ec1u \u0111\u1ed9 ch\u00eanh \u00e1p \u0111o b\u1eb1ng th\u00f4ng tim. Ng\u01b0\u1ee3c l\u1ea1i l\u00f2ng m\u1ea1ch c\u00e0ng b\u1ecb nh\u1ecf h\u1eb9p, s\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c c\u00e0ng nhi\u1ec1u, \u0111\u1ed9 ch\u00eanh \u00e1p \u0111o b\u1eb1ng si\u00eau \u00e2m Doppler kh\u00e1c bi\u1ec7t nhi\u1ec1u \u0111\u1ed9 ch\u00eanh \u00e1p \u0111o b\u1eb1ng th\u00f4ng tim.<\/p>\n<p style=\"text-align: justify;\">Do \u0111\u00f3 trong th\u1ef1c h\u00e0nh l\u00e2m s\u00e0ng, ng\u01b0\u1eddi ta ph\u1ea3i t\u00ednh \u0111\u1ebfn s\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c n\u00e0y \u0111\u1ec3 hi\u1ec7u ch\u1ec9nh k\u1ebft qu\u1ea3 \u0111\u1ed9 ch\u00eanh \u00e1p \u0111o \u0111\u01b0\u1ee3c. C\u00f4ng th\u1ee9c t\u00ednh \u0111\u1ed9 \u00e1p l\u1ef1c \u0111\u01b0\u1ee3c ph\u1ee5c h\u1ed3i (PR)<\/p>\n<p style=\"text-align: left;\">PR = 4 * Vmax<sup><span style=\"font-family: Arial;\">2<\/span><\/sup>\u00a0* C<br \/>C = 2 * (AVA \/ AscAA) * (1- AVA \/ AscAA)<\/p>\n<p style=\"text-align: left;\">AVA: di\u1ec7n t\u00edch m\u1edf van \u0110MC<br \/>AscAA: di\u1ec7n t\u00edch \u0110MC l\u00ean<\/p>\n<p>S\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c tr\u1edf n\u00ean \u0111\u00e1ng k\u1ec3 h\u01a1n khi:<\/p>\n<ul>\n<li>G\u1ed1c \u0110MC, \u0110MC l\u00ean nh\u1ecf (&lt; 3cm)<\/li>\n<li>H\u1eb9p \u0110MC h\u00ecnh v\u00f2m b\u1ea9m sinh<\/li>\n<li>M\u1ed9t s\u1ed1 lo\u1ea1i van nh\u00e2n t\u1ea1o<\/li>\n<li>H\u1eb9p thu\u00f4n<\/li>\n<li>H\u1eb9p tr\u00ean van \u0110MC<\/li>\n<li>H\u1eb9p eo \u0110MC<\/li>\n<\/ul>\n<p>T\u00e0i li\u1ec7u tham kh\u1ea3o:<br \/><a href=\"http:\/\/saric.us\/echonomy\/Pressure%20Recovery.htm\"><code>Pressure Recovery<br \/><\/code><\/a><a href=\"https:\/\/drsvenkatesan.com\/2017\/12\/20\/pressure-recovery-phenomenon\/\"><code>pressure recovery phenomenon\/<\/code><\/a><\/p>\n\n\n\n<p class=\"wp-block-paragraph\"><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Trong c\u00e1c t\u00e0i li\u1ec7u si\u00eau \u00e2m tim th\u01b0\u1eddng nh\u1eafc \u0111\u1ebfn kh\u00e1i ni\u1ec7u &#8220;S\u1ef1 ph\u1ee5c h\u1ed3i \u00e1p l\u1ef1c&#8221;, \u0111\u1eb7c bi\u1ec7t trong h\u1eb9p van \u0111\u1ed9ng m\u1ea1ch ch\u1ee7.<\/p>\n","protected":false},"author":1,"featured_media":233,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[40,39,37,36,38],"class_list":["post-230","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-doc-sach-cho-vui","tag-dong-mach-chu","tag-hep-van-dong-mach-chu","tag-phuc-hoi-ap-luc","tag-pressure-recovery","tag-sieu-am-tim"],"_links":{"self":[{"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/posts\/230","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/comments?post=230"}],"version-history":[{"count":12,"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/posts\/230\/revisions"}],"predecessor-version":[{"id":253,"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/posts\/230\/revisions\/253"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/media\/233"}],"wp:attachment":[{"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/media?parent=230"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/categories?post=230"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/cdha.edu.vn\/cdha\/wp-json\/wp\/v2\/tags?post=230"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}