{"id":8120,"date":"2024-05-10T18:58:58","date_gmt":"2024-05-10T10:58:58","guid":{"rendered":"https:\/\/tommykwan.com\/blog\/?p=8120"},"modified":"2024-05-12T13:02:14","modified_gmt":"2024-05-12T05:02:14","slug":"mach-crit-mcrit","status":"publish","type":"post","link":"https:\/\/tommykwan.com\/blog\/aviation\/mach-crit-mcrit\/","title":{"rendered":"Mach Crit (Mcrit)?"},"content":{"rendered":"<p>Ref FAA PHAK 5-45<\/p>\n<p><span style=\"text-decoration: underline;\">What&#8217;s Mcrit &#8211; Mach Crit?<\/span><\/p>\n<p>Ans: <strong>airflow over any part of the aircraft<\/strong> or structure under consideration first<strong> reaches<\/strong> (<strong>but<\/strong> does <strong>not exceed<\/strong>)<strong> Mach 1.0<\/strong>.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-8139 size-full\" src=\"https:\/\/tommykwan.com\/blog\/wp-content\/uploads\/2024\/05\/Fig-5-64.png\" alt=\"\" width=\"436\" height=\"327\" srcset=\"https:\/\/tommykwan.com\/blog\/wp-content\/uploads\/2024\/05\/Fig-5-64.png 436w, https:\/\/tommykwan.com\/blog\/wp-content\/uploads\/2024\/05\/Fig-5-64-300x225.png 300w\" sizes=\"auto, (max-width: 436px) 100vw, 436px\" \/><\/p>\n<div class=\"embed-container\"><iframe loading=\"lazy\" title=\"What is Critical Mach Number?\" width=\"1170\" height=\"658\" src=\"https:\/\/www.youtube.com\/embed\/Ntridyss88Q?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe><\/div>\n<p>&nbsp;<\/p>\n<p><span style=\"text-decoration: underline;\">Design of increase Mcrit (delay occurrence of shock wave) ?<\/span><\/p>\n<ol>\n<li>Thin airfoil (reduce the thickness)\n<ul>\n<li>drawbacks: reduce the wing tank volumn<\/li>\n<\/ul>\n<\/li>\n<li>Sweepback\n<ul>\n<li>drawbacks: need to fly faster to compensate, and that is why the aircraft need high lift devices to maintain T\/O performance<\/li>\n<\/ul>\n<\/li>\n<li>vortex generators<br \/>\nfunction: delay the onset of separation by creating a vortex which mixes boundary airflow with high energy<br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/cdn.boldmethod.com\/images\/learn-to-fly\/aerodynamics\/vortex-generators\/wing-without-vortex-generators.jpg\" alt=\"wing-without-vortex-generators\" width=\"380\" height=\"219\" \/><br \/>\n<img loading=\"lazy\" decoding=\"async\" class=\"\" src=\"https:\/\/cdn.boldmethod.com\/images\/learn-to-fly\/aerodynamics\/vortex-generators\/wing-with-vortex-generators.jpg\" alt=\"wing-with-vortex-generators\" width=\"382\" height=\"199\" \/><\/li>\n<\/ol>\n<p><a href=\"https:\/\/youtu.be\/XTyNTdR8p6g?si=dR1r2RN7JlCE8YO7&amp;t=690\">Ref: https:\/\/youtu.be\/XTyNTdR8p6g?si=dR1r2RN7JlCE8YO7&amp;t=690<\/a><\/p>\n<div class=\"embed-container\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"Fv1dP7orTa\"><p><a href=\"https:\/\/tommykwan.com\/blog\/aviation\/shock-wave\/\">Shock wave<\/a><\/p><\/blockquote>\n<p><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"&#8220;Shock wave&#8221; &#8212; Tommy&#039;s Diaries\" src=\"https:\/\/tommykwan.com\/blog\/aviation\/shock-wave\/embed\/#?secret=TQbej0vEPx#?secret=Fv1dP7orTa\" data-secret=\"Fv1dP7orTa\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/div>\n<div class=\"embed-container\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"ghylO8pTkx\"><p><a href=\"https:\/\/tommykwan.com\/blog\/aviation\/mach-number-sonic-subsonic-transonic\/\">Mach number &#8211; Sonic, subsonic, transonic?<\/a><\/p><\/blockquote>\n<p><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; clip: rect(1px, 1px, 1px, 1px);\" title=\"&#8220;Mach number &#8211; Sonic, subsonic, transonic?&#8221; &#8212; Tommy&#039;s Diaries\" src=\"https:\/\/tommykwan.com\/blog\/aviation\/mach-number-sonic-subsonic-transonic\/embed\/#?secret=a8LxVbBOGd#?secret=ghylO8pTkx\" data-secret=\"ghylO8pTkx\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Ref FAA PHAK 5-45 What&#8217;s Mcrit &#8211; Mach Crit? Ans: airflow over any part of the aircraft or structure under consideration first reaches (but does not exceed) Mach 1.0. &nbsp; Design of increase Mcrit (delay occurrence of shock wave) ? Thin airfoil (reduce the thickness) drawbacks: reduce the wing tank volumn Sweepback drawbacks: need to<a class=\"read-more \" href=\"https:\/\/tommykwan.com\/blog\/aviation\/mach-crit-mcrit\/\" title=\"Read More\"> <span class=\"button default\">Read More<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[68,64],"tags":[],"class_list":["post-8120","post","type-post","status-publish","format-standard","hentry","category-atpl-knowledge","category-aviation"],"_links":{"self":[{"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/posts\/8120","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/comments?post=8120"}],"version-history":[{"count":19,"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/posts\/8120\/revisions"}],"predecessor-version":[{"id":8164,"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/posts\/8120\/revisions\/8164"}],"wp:attachment":[{"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/media?parent=8120"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/categories?post=8120"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tommykwan.com\/blog\/wp-json\/wp\/v2\/tags?post=8120"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}