{"id":392978,"date":"2024-11-06T13:32:01","date_gmt":"2024-11-06T13:32:01","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/why-does-source-size-keep-expanding-automatically\/"},"modified":"2024-11-06T13:32:01","modified_gmt":"2024-11-06T13:32:01","slug":"why-does-source-size-keep-expanding-automatically","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/why-does-source-size-keep-expanding-automatically\/","title":{"rendered":"Why does source size keep expanding automatically?"},"content":{"rendered":"<p>&lt;p&gt;I have a 3D periodic structure, illuminated by a plane wave source (BFAST) at an angle.&nbsp;&lt;\/p&gt;&lt;p&gt;I have set the source footprint geometry to the same dimension as the periodic region (i.e. same as cross sectional dimension of structure and mesh). Whenever I run the solver, it automatically increases the size of the source geometry, doubling each dimension. See the below screenshot, in which the white outline of the source has been expanded and no longer coincides with the orange line (mesh boundary).&nbsp;&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/06-11-2024-1730899834-mceclip0.png\" \/>&lt;\/p&gt;&lt;p&gt;Side view for context:&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2024\/11\/06-11-2024-1730899880-mceclip1.png\" \/>&lt;\/p&gt;&lt;p&gt;Thanks!&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-392978","topic","type-topic","status-publish","hentry","topic-tag-photonics"],"aioseo_notices":[],"aioseo_head":"\n\t\t<!-- All in One SEO 4.9.10 - aioseo.com -->\n\t<meta name=\"description\" content=\"I have a 3D periodic structure, illuminated by a plane wave source (BFAST) at an angle. I have set the source footprint geometry to the same dimension as the periodic region (i.e. same as cross sectional dimension of structure and mesh). Whenever I run the solver, it automatically increases the size of the source geometry, doubling\" \/>\n\t<meta name=\"robots\" content=\"max-image-preview:large\" \/>\n\t<link rel=\"canonical\" href=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/why-does-source-size-keep-expanding-automatically\/\" \/>\n\t<meta name=\"generator\" content=\"All in One SEO (AIOSEO) 4.9.10\" \/>\n\t\t<meta property=\"og:locale\" content=\"en_US\" \/>\n\t\t<meta property=\"og:site_name\" content=\"Ansys Learning Forum | Ansys Innovation Space\" \/>\n\t\t<meta property=\"og:type\" content=\"article\" \/>\n\t\t<meta property=\"og:title\" content=\"Why does source size keep expanding automatically? | Ansys Learning Forum\" \/>\n\t\t<meta property=\"og:description\" content=\"I have a 3D periodic structure, illuminated by a plane wave source (BFAST) at an angle. I have set the source footprint geometry to the same dimension as the periodic region (i.e. same as cross sectional dimension of structure and mesh). Whenever I run the solver, it automatically increases the size of the source geometry, doubling\" \/>\n\t\t<meta property=\"og:url\" content=\"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/why-does-source-size-keep-expanding-automatically\/\" \/>\n\t\t<meta property=\"article:published_time\" content=\"2024-11-06T13:32:01+00:00\" \/>\n\t\t<meta property=\"article:modified_time\" content=\"2024-11-06T13:32:01+00:00\" \/>\n\t\t<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n\t\t<meta name=\"twitter:title\" content=\"Why does source size keep expanding automatically? | Ansys Learning Forum\" \/>\n\t\t<meta name=\"twitter:description\" content=\"I have a 3D periodic structure, illuminated by a plane wave source (BFAST) at an angle. I have set the source footprint geometry to the same dimension as the periodic region (i.e. same as cross sectional dimension of structure and mesh). Whenever I run the solver, it automatically increases the size of the source geometry, doubling\" \/>\n\t\t<script type=\"application\/ld+json\" class=\"aioseo-schema\">\n\t\t\t{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/why-does-source-size-keep-expanding-automatically\\\/#breadcrumblist\",\"itemListElement\":[{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"position\":2,\"name\":\"Topics\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/photonics\\\/#listItem\",\"name\":\"photonics\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum#listItem\",\"name\":\"Home\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/photonics\\\/#listItem\",\"position\":3,\"name\":\"photonics\",\"item\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/photonics\\\/\",\"nextItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/why-does-source-size-keep-expanding-automatically\\\/#listItem\",\"name\":\"Why does source size keep expanding automatically?\"},\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/topics\\\/#listItem\",\"name\":\"Topics\"}},{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/why-does-source-size-keep-expanding-automatically\\\/#listItem\",\"position\":4,\"name\":\"Why does source size keep expanding automatically?\",\"previousItem\":{\"@type\":\"ListItem\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic-tag\\\/photonics\\\/#listItem\",\"name\":\"photonics\"}}]},{\"@type\":\"Organization\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/#organization\",\"name\":\"Ansys Learning Forum\",\"description\":\"Ansys Innovation Space\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/\"},{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/why-does-source-size-keep-expanding-automatically\\\/#webpage\",\"url\":\"https:\\\/\\\/innovationspace.ansys.com\\\/forum\\\/forums\\\/topic\\\/why-does-source-size-keep-expanding-automatically\\\/\",\"name\":\"Why does source size keep expanding automatically? | Ansys Learning Forum\",\"description\":\"I have a 3D periodic structure, illuminated by a plane wave source (BFAST) at an angle. 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