{"id":164658,"date":"2023-03-17T08:58:20","date_gmt":"2023-03-17T08:58:20","guid":{"rendered":"\/knowledge\/forums\/topic\/how-to-calculate-the-frontal-area-of-a-convex-closed-surface\/"},"modified":"2023-07-31T12:26:00","modified_gmt":"2023-07-31T12:26:00","slug":"how-to-calculate-the-frontal-area-of-a-convex-closed-surface","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/knowledge\/forums\/topic\/how-to-calculate-the-frontal-area-of-a-convex-closed-surface\/","title":{"rendered":"How to calculate the frontal area of a convex closed surface?"},"content":{"rendered":"<p>The frontal area can be calculated with the following CEL:  IntegrationVariable = Normal X\/abs(Normal X + 1e-8) FrontalArea = 0.5 * areaInt_x( IntegrationVariable )@Body  This example CEL is for the frontal area in x-direction.   With areaInt_x the integral of the area components in x-direction multiplied with an integration variable Phi is obtained. To obtain the area in x-direction, the integration variable must have a value of 1. However, as the x-component of the areas has a sign, the expression areaInt_x(1)@body will result in a value of zero for a closed surface.  So use the integration variable Phi = Normal X\/abs(Normal X) to obtain a +1 or -1 depending on the local area, and hence to obtain the integral of the absolute values of the area x-component. The small number is just required to avoid division by zero for area that have no x-component. The result is the double of the frontal area, so include the 0.5 to get the correct frontal area.  Note that this approach works only for convex surfaces.<\/p>\n","protected":false},"template":"","class_list":["post-164658","topic","type-topic","status-publish","hentry","topic-tag-cfd-post","topic-tag-fluid-dynamics","topic-tag-general"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_wp_page_template":["default"],"_bbp_last_active_time":["3-15-2023  20:20:45"],"_bbp_forum_id":["27796"],"_bbp_author_ip":["23.56.168.180"],"_btv_view_count":["742"],"siebel_km_number":["444691"],"product_version":[""],"km_published_date":["2005-10-25T00:00:00.000Z"],"family":["Fluid Dynamics"],"application_name":["CFD-Post"]},"test":"articlesansys-com"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/164658","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/topics\/164658\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/knowledge\/wp-json\/wp\/v2\/media?parent=164658"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}