{"id":283322,"date":"2023-05-10T16:03:09","date_gmt":"2023-05-10T16:03:09","guid":{"rendered":"\/forum\/forums\/topic\/different-heat-transfer-results-when-using-compressive-or-geo-reconstruct\/"},"modified":"2023-05-10T16:03:09","modified_gmt":"2023-05-10T16:03:09","slug":"different-heat-transfer-results-when-using-compressive-or-geo-reconstruct","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/different-heat-transfer-results-when-using-compressive-or-geo-reconstruct\/","title":{"rendered":"Different heat transfer results when using compressive or geo-reconstruct"},"content":{"rendered":"<p>I&#8217;m simulating condensation of water on a 2D pipe. I have written a UDF using the DEFINE_MASS_TRANSFER macro to determine the mass transfer rate of the vapour via using an energy balance method which forces the interface temperature to stay at saturation temperature each time step using this law.<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/05\/10-05-2023-1683734489-mceclip2.png\" width=\"155\" height=\"42\">&nbsp;<\/p>\n<p>When using the compressive interface tracking method with a slope limiter value of 1, I&#8217;ve manage to validate the film thickness against the Nusselt theory. However my heat transfer coefficient\/heat flux values are completly wrong. I obtain a value of around 2500 W\/m2K when it should be 9000 W\/m2K. I&#8217;ve even set the reference temperature to be equal to saturation. The same can be said for the temperature and velocity profiles. Also, the temperature at the interface does not equal saturation as it is meant to. This can be seen on the picture<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"\/forum\/wp-content\/uploads\/sites\/2\/2023\/05\/10-05-2023-1683734165-mceclip1.png\" width=\"664\" height=\"385\"><\/p>\n<p>Although, when using the geometric reconstruct, the film thickness is much larger than it should be but however, I obtain higher heat transfer coeffcients than I did with the compressive method (4500 W\/m2K). And the interface temperature is closer to saturation (369K).<\/p>\n<p>I&#8217;m not sure why the interface temperature for the compressive method is much lower than saturation but I obtain the correct film thickness, not to mention having much lower heat transfer coefficients as the heat transfer coefficient is a function of the film thickness due to thermal resistance?<\/p>\n<p>Kind regards.<\/p>\n","protected":false},"template":"","class_list":["post-283322","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["187856","199"],"_bbp_author_ip":["23.217.200.20"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["602"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["283322"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","187856"],"_bbp_voice_count":["2"],"_bbp_reply_count":["23"],"_bbp_last_reply_id":["284000"],"_bbp_last_active_id":["284000"],"_bbp_last_active_time":["2023-05-15 12:44:27"]},"test":"navsing"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/283322","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\/283322\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=283322"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}