{"id":364506,"date":"2024-04-27T06:59:45","date_gmt":"2024-04-27T06:59:45","guid":{"rendered":"\/forum\/forums\/reply\/364506\/"},"modified":"2024-04-27T06:59:45","modified_gmt":"2024-04-27T06:59:45","slug":"364506","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/364506\/","title":{"rendered":"Reply To: Help needed for steady state thermal analysis of rectangular fins and validation"},"content":{"rendered":"<p>&lt;p&gt;Thanks for the suggestion. Yes, you are correct, I had only used the formula for long fin. So what I did was, instead of declaring convection for both the surface of the engine block as well as the surface of the fin, I declared them seperately, and added a reaction probe result to get the heat flow from fins alone. Coupled with that I calculated fin tip temperature and heat flow for all 3 types of fins (long fin, short fin with insulated end, and short fin with end not insulated) as provided in the databook, with results as shown below:&lt;\/p&gt;&lt;p&gt;<img decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/04\/27-04-2024-1714200430-straight_rectangular_calculation.png\" alt=\"\" \/>&lt;\/p&gt;&lt;p&gt;Based on above values, I find that &#8220;short fin, end not insulated&#8221; has values closest to ANSYS results, so I&#8217;m going to go forward with that.&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;Just one other query: Here&#8217;s a similar engine block but with triangular fins:&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2024\/04\/27-04-2024-1714200851-mceclip0.png\" width=\"687\" height=\"259\" \/>&lt;\/p&gt;&lt;p&gt;Here, I&#8217;m planning to use the same formulas for verification. But I need to know how to find the value of cross-sectional area and perimeter of the cross-section to input in the formula, since unlike rectangular fins, the cross-section changes along the fin here. Appreciate the help!&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-364506","reply","type-reply","status-publish","hentry"],"aioseo_notices":[],"acf":[],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/364506","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies"}],"about":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/types\/reply"}],"version-history":[{"count":0,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/replies\/364506\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=364506"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}