{"id":460408,"date":"2026-06-26T12:32:58","date_gmt":"2026-06-26T12:32:58","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/spray-near-symmetry-boundaries\/"},"modified":"2026-06-26T12:32:58","modified_gmt":"2026-06-26T12:32:58","slug":"spray-near-symmetry-boundaries","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/spray-near-symmetry-boundaries\/","title":{"rendered":"Spray near symmetry boundaries"},"content":{"rendered":"<p>&lt;p&gt;Hello,&lt;\/p&gt;&lt;p&gt;I am setting up a closed-cycle simulation of a diesel engine combustion chamber (from Intake Valve Closing (IVC) to Exhaust Valve Opening (EVO)) and I have a question regarding the use of symmetry in my model.&lt;\/p&gt;&lt;p class=&#8221;isSelectedEnd&#8221;&gt;The cylinder head is flat, and the fuel injector is located exactly at the center of the head, which makes the geometry favorable for the use of symmetry.&lt;\/p&gt;&lt;p&gt;The piston bowl is somewhat complex, but it has a 90&deg; rotational symmetry, as shown in the images below.&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2026\/06\/26-06-2026-1782476543-mceclip0.png\" width=\"378\" height=\"354\" \/>&lt;\/p&gt;&lt;p&gt;&nbsp;&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2026\/06\/26-06-2026-1782476621-mceclip1.png\" width=\"290\" height=\"360\" \/>&lt;\/p&gt;&lt;p&gt;The issue is that my injector has 13 nozzle holes. If it had 12 holes, a 90&deg; sector would naturally contain 3 nozzles, making the setup straightforward.&lt;\/p&gt;&lt;p&gt;However, with 13 holes, defining the nozzles in the sector becomes somewhat awkward. The nozzle holes near the sector boundaries end up very close to the symmetry planes, so the corresponding spray solid cones appear to be partially inside and partially outside the computational domain, at least visually.&lt;\/p&gt;&lt;p&gt;<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/innovationspace.ansys.com\/forum\/wp-content\/uploads\/sites\/2\/2026\/06\/26-06-2026-1782476866-mceclip2.png\" width=\"299\" height=\"301\" \/>&lt;\/p&gt;&lt;p class=&#8221;isSelectedEnd&#8221;&gt;Since this is a relatively large combustion chamber, running a full 360&deg; simulation would be computationally expensive.&lt;\/p&gt;&lt;p class=&#8221;isSelectedEnd&#8221;&gt;Do you have any suggestions on how to handle this situation?&lt;\/p&gt;&lt;p class=&#8221;isSelectedEnd&#8221;&gt;Thank you in advance.&lt;\/p&gt;&lt;p class=&#8221;isSelectedEnd&#8221;&gt;Best regards,&lt;\/p&gt;&lt;p&gt;Elias&lt;\/p&gt;<\/p>\n","protected":false},"template":"","class_list":["post-460408","topic","type-topic","status-publish","hentry","topic-tag-ansys-forte","topic-tag-cyclic-symmetry","topic-tag-diesel-engine"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_forum_id":["27792"],"_bbp_topic_id":["460408"],"_bbp_subscription":["504319","199"],"_bbp_author_ip":["201.16.234.164"],"_bbp_last_reply_id":["460415"],"_bbp_last_active_id":["460415"],"_bbp_last_active_time":["2026-06-26 15:32:09"],"_bbp_reply_count":["3"],"_bbp_reply_count_hidden":["0"],"_bbp_voice_count":["2"],"_bbp_engagement":["504319","199"],"_btv_view_count":["29"],"_bbp_topic_status":["unanswered"]},"test":"elias-amancioiati-org-br"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/460408","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\/460408\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=460408"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}