{"id":660,"date":"2017-10-12T22:36:49","date_gmt":"2017-10-12T22:36:49","guid":{"rendered":"https:\/\/learn.hydrologystudio.com\/channel-studio\/?post_type=ht_kb&#038;p=660"},"modified":"2017-10-13T16:20:48","modified_gmt":"2017-10-13T16:20:48","slug":"inlet-control","status":"publish","type":"ht_kb","link":"https:\/\/learn.hydrologystudio.com\/channel-studio\/knowledge-base\/inlet-control\/","title":{"rendered":"Inlet Control"},"content":{"rendered":"<p>Inlet control occurs when it is harder for the flow to get through the entrance of the pipe than the remainder of the pipe barrel.<\/p>\n<p>The profile below illustrates a type of inlet control flow. The control section is at the inlet end of the culvert. Depending on the tailwater and culvert slope, a hydraulic jump may occur downstream of the inlet.<\/p>\n<figure id=\"attachment_652\" aria-describedby=\"caption-attachment-652\" style=\"width: 643px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-652 size-large\" src=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/InletControlProfile-1024x469.png\" alt=\"\" width=\"643\" height=\"294\" srcset=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/InletControlProfile-1024x469.png 1024w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/InletControlProfile-300x137.png 300w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/InletControlProfile-768x351.png 768w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/InletControlProfile-50x23.png 50w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/InletControlProfile-60x27.png 60w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/InletControlProfile-100x46.png 100w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/InletControlProfile.png 1355w\" sizes=\"auto, (max-width: 643px) 100vw, 643px\" \/><figcaption id=\"caption-attachment-652\" class=\"wp-caption-text\">Culvert flowing under Inlet Control<\/figcaption><\/figure>\n<p>The following inlet control equations are used. If Hw is above the pipe crown the submerged equation is used. Otherwise the unsubmerged equation is used.<\/p>\n<p><strong>Submerged<\/strong><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-564\" src=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqSubmerged.jpg\" alt=\"\" width=\"265\" height=\"91\" srcset=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqSubmerged.jpg 265w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqSubmerged-50x17.jpg 50w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqSubmerged-60x21.jpg 60w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqSubmerged-100x34.jpg 100w\" sizes=\"auto, (max-width: 265px) 100vw, 265px\" \/><\/p>\n<p><strong>Unsubmerged<\/strong><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-large wp-image-661\" src=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqUnsubmerged.jpg\" alt=\"\" width=\"226\" height=\"89\" srcset=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqUnsubmerged.jpg 226w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqUnsubmerged-50x20.jpg 50w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqUnsubmerged-60x24.jpg 60w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqUnsubmerged-100x39.jpg 100w\" sizes=\"auto, (max-width: 226px) 100vw, 226px\" \/><\/p>\n<p>Where:<\/p>\n<p>Hw = Headwater depth above invert<br \/>\nD = Culvert Rise<br \/>\nQ = Flow rate<br \/>\nA = Full cross-sectional area of pipe<br \/>\nK, M, c, Y = Coefficients based on inlet edge configurations<br \/>\nS = Culvert slope<\/p>\n","protected":false},"excerpt":{"rendered":"<p>How inlet control flow conditions are calculated<\/p>\n","protected":false},"author":1,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"footnotes":""},"ht-kb-category":[42],"ht-kb-tag":[],"class_list":["post-660","ht_kb","type-ht_kb","status-publish","format-standard","hentry","ht_kb_category-culverts"],"_links":{"self":[{"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb\/660","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb"}],"about":[{"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/types\/ht_kb"}],"author":[{"embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/comments?post=660"}],"version-history":[{"count":4,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb\/660\/revisions"}],"predecessor-version":[{"id":665,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb\/660\/revisions\/665"}],"wp:attachment":[{"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/media?parent=660"}],"wp:term":[{"taxonomy":"ht_kb_category","embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb-category?post=660"},{"taxonomy":"ht_kb_tag","embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb-tag?post=660"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}