{"id":573,"date":"2017-10-12T16:48:35","date_gmt":"2017-10-12T16:48:35","guid":{"rendered":"https:\/\/learn.hydrologystudio.com\/channel-studio\/?post_type=ht_kb&#038;p=573"},"modified":"2020-04-21T14:36:11","modified_gmt":"2020-04-21T14:36:11","slug":"expansion-contraction-losses","status":"publish","type":"ht_kb","link":"https:\/\/learn.hydrologystudio.com\/channel-studio\/knowledge-base\/expansion-contraction-losses\/","title":{"rendered":"Expansion Contraction Losses"},"content":{"rendered":"<p>Contraction and expansion losses are typically small compared to friction losses but become more significant around culvert and bridge openings. Channel Studio evaluates these losses using the following equation:<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-551\" src=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqExpContrNew.png\" alt=\"\" width=\"222\" height=\"80\" srcset=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqExpContrNew.png 222w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqExpContrNew-50x18.png 50w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqExpContrNew-60x22.png 60w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/EqExpContrNew-100x36.png 100w\" sizes=\"auto, (max-width: 222px) 100vw, 222px\" \/><br \/>\nWhere:<\/p>\n<p><strong>h<\/strong>ce = The energy loss from expansion or contraction<br \/>\nC = The contraction or expansion coefficient (See <a href=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/knowledge-base\/project-settings\/\">Project Settings<\/a> for default values)<\/p>\n<p>This method assumes that a <em>contraction<\/em> is occurring whenever the velocity head downstream is greater than the velocity head upstream. Likewise, when the velocity head upstream is greater than the velocity head downstream, it is assumed that a flow <em>expansion<\/em> is taking place.<\/p>\n<figure id=\"attachment_574\" aria-describedby=\"caption-attachment-574\" style=\"width: 632px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-574 size-full\" src=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/ExpansionContraction.png\" alt=\"\" width=\"632\" height=\"504\" srcset=\"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/ExpansionContraction.png 632w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/ExpansionContraction-300x239.png 300w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/ExpansionContraction-50x40.png 50w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/ExpansionContraction-60x48.png 60w, https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-content\/uploads\/sites\/5\/2017\/10\/ExpansionContraction-100x80.png 100w\" sizes=\"auto, (max-width: 632px) 100vw, 632px\" \/><figcaption id=\"caption-attachment-574\" class=\"wp-caption-text\">From 5 to 4, velocity is increasing. From 2 to 1, velocity is decreasing.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>How Channel Studio calculates Expansion and Contraction losses<\/p>\n","protected":false},"author":1,"comment_status":"closed","ping_status":"closed","template":"","format":"standard","meta":{"footnotes":""},"ht-kb-category":[40],"ht-kb-tag":[],"class_list":["post-573","ht_kb","type-ht_kb","status-publish","format-standard","hentry","ht_kb_category-open-channels"],"_links":{"self":[{"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb\/573","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=573"}],"version-history":[{"count":4,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb\/573\/revisions"}],"predecessor-version":[{"id":1128,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb\/573\/revisions\/1128"}],"wp:attachment":[{"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/media?parent=573"}],"wp:term":[{"taxonomy":"ht_kb_category","embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb-category?post=573"},{"taxonomy":"ht_kb_tag","embeddable":true,"href":"https:\/\/learn.hydrologystudio.com\/channel-studio\/wp-json\/wp\/v2\/ht-kb-tag?post=573"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}