{"id":388738,"date":"2024-10-09T10:08:02","date_gmt":"2024-10-09T10:08:02","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/fluent-runtime-dft-with-unsteady-boundary-condition\/"},"modified":"2024-10-09T10:08:02","modified_gmt":"2024-10-09T10:08:02","slug":"fluent-runtime-dft-with-unsteady-boundary-condition","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/fluent-runtime-dft-with-unsteady-boundary-condition\/","title":{"rendered":"Fluent &#8211; Runtime DFT with unsteady boundary condition"},"content":{"rendered":"<p>&lt;p&gt;Hi. I have a simulation where I want to utilise the Runtime DFT capabilities to give me Fourier coefficients in the domain for different discrete frequencies. I am using the single tone runtime DFT option for static pressure at a single frequency (for testing purposes). For reasons I&#8217;m not clear on, following sufficient run time, the DFT results are zero for both magnitude and phase.&nbsp;&lt;\/p&gt;&lt;p&gt;I suspect this may be due to the fact that when I run the calculation, I have a boundary condition that updates at every time step (following each time step, a new pressure profile is defined at one boundary). Would this implementation be a reason that the Runtime DFT option would not work correctly? Surely, if the data is still in memory (i.e. the simulation isn&#8217;t closed during the runtime required), the DFT should still work. I&#8217;m wondering if anyone has any experience or suggestions?&lt;\/p&gt;&lt;p&gt;Thanks in advance,&lt;\/p&gt;&lt;p&gt;Joe&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-388738","topic","type-topic","status-publish","hentry","topic-tag-fluent","topic-tag-fluids","topic-tag-turbomachinery"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["269889","13659"],"_bbp_author_ip":["152.78.242.153"],"_btv_view_count":["410"],"_bbp_topic_status":["unanswered"],"_bbp_likes_count":["1"],"_bbp_topic_id":["388738"],"_bbp_forum_id":["27792"],"_bbp_engagement":["13659","269889"],"_bbp_voice_count":["2"],"_bbp_reply_count":["5"],"_bbp_last_reply_id":["394958"],"_bbp_last_active_id":["394958"],"_bbp_last_active_time":["2024-11-22 12:25:33"]},"test":"jspb1g21soton-ac-uk"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/388738","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/topic"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/388738\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=388738"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}