{"id":378067,"date":"2024-08-13T07:14:01","date_gmt":"2024-08-13T07:14:01","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/378067\/"},"modified":"2024-08-13T07:14:01","modified_gmt":"2024-08-13T07:14:01","slug":"378067","status":"publish","type":"reply","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/reply\/378067\/","title":{"rendered":"Reply To: Volume Fraction too Low. How to Improve?"},"content":{"rendered":"

<p>Hi, <\/p><p>I exported ansys data using method 2 for only vapordomain_tubewall (interface) and then calculated the HTC and Heat transfer rate using correlations used by books and papers.<br>  and Q = hAdT. <\/p><p>If we check below table, ANSYS fluent results are taken directly from Fluent Software. <\/p><table style=”border-collapse: collapse; width: 476px; height: 106.66px;” border=”0″ width=”389″ cellspacing=”0″ cellpadding=”0″><colgroup><col style=”width: 133px;” width=”115″> <col style=”width: 115px;” width=”85″> <col style=”width: 111px;” width=”90″> <col style=”width: 117px;” width=”99″> <\/colgroup><tbody><tr style=”height: 52.26px;”><td class=”xl71″ style=”height: 52.26px; width: 86pt; text-align: center;” width=”115″ height=”38″><span style=”font-size: 10pt;”>Properties<\/span><\/td><td class=”xl67″ style=”border-left: none; width: 64pt; height: 52.26px; text-align: center;” width=”85″><span style=”font-size: 10pt;”>Theoretical HTC<\/span><\/td><td class=”xl67″ style=”border-left: none; width: 67pt; height: 52.26px; text-align: center;” width=”90″><span style=”font-size: 10pt;”>ANSYS Export<\/span><\/td><td class=”xl68″ style=”border-left: none; width: 74pt; height: 52.26px; text-align: center;” width=”99″><span style=”font-size: 10pt;”>ANSYS Fluent Results<\/span><\/td><\/tr><tr style=”height: 27.2px;”><td class=”xl69″ style=”height: 27.2px; border-top: none; text-align: center;” height=”27″><span style=”font-size: 10pt;”>HTC<\/span><\/strong><\/td><td class=”xl63″ style=”border-top: none; border-left: none; height: 27.2px; text-align: center;”><span style=”font-size: 10pt;”>6518<\/span><\/td><td class=”xl63″ style=”border-top: none; border-left: none; height: 27.2px; text-align: center;”><span style=”font-size: 10pt;”>7697<\/span><\/td><td class=”xl66″ style=”border-top: none; border-left: none; height: 27.2px; text-align: center;”><span style=”font-size: 10pt;”>1514<\/span><\/td><\/tr><tr style=”height: 27.2px;”><td class=”xl70″ style=”height: 27.2px; border-top: none; text-align: center;” height=”27″><span style=”font-size: 10pt;”>Heat Transfer Rate<\/span><\/strong><\/td><td class=”xl64″ style=”border-top: none; border-left: none; height: 27.2px; text-align: center;”><span style=”font-size: 10pt;”>3295<\/span><\/td><td class=”xl64″ style=”border-top: none; border-left: none; height: 27.2px; text-align: center;”><span style=”font-size: 10pt;”>1984<\/span><\/td><td class=”xl65″ style=”border-top: none; border-left: none; height: 27.2px; text-align: center;”><span style=”font-size: 10pt;”>351<\/span><\/td><\/tr><\/tbody><\/table><p>Note: All ANSYS Export values(density, K, viscosity) are averaged out by exporting only vapordomain_tubewall interface<\/strong>.<\/p><p>For (Tvapor – Twall); Twall = temperture we fixed at thermal BC and Tvapor = Export > vapor domain only > static temperature and then took area weighted average of it. <\/p><p>If we compare theoretical with ANSYS Export, the error lies within 20%, which is reasonable but there is a very big discrepancy between ANSYS exported data vs ANSYS calculates itself. My question is, is this normal discrepancy if we export data and calculates ourselves and also is the method to get the raw data is ok or not?<\/p><\/p>\n","protected":false},"template":"","class_list":["post-378067","reply","type-reply","status-publish","hentry"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t