Hi all,<\/p>\n
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I know there is already enough discussion on how to control or analyze continuity residuals. One suggestion states that “keep the imbalance less than 1%”. And also nobody explicitly expresses what will happen if the fluid is compressible and shock is entering in the domain. So let me explain what I am doing and what specific questions I hope to get the answer for.<\/p>\n
<\/p>\n
My problem is multiphase, transient, compressible. The domain is 5mm x 5mm axisymmetric. x-axis is the ‘axis’, while there is a pressure inlet at right and pressure outlet in the left, and the top is the wall. whole domain is initialized with 101325 pa (P_op = 0 Pa) and then a vapor bubble of spherical shape is patched. Pressure inlet is defined such that 2GPa shock enter with Mach 2. I want to collapse the bubble with shock interaction. Now after some iteration, if I check the “mass imbalance” from contour plot I see it varies from -1E-7 to +1E-7. This is definitely cell based value. Now If I calculate mass flow rate from ‘report’ and select inlet and outlet and I see the net mass flow in the order of, O(1E3).<\/p>\n
<\/p>\n
1. So my first question is how to compare the net mass flow rate in the domain (inlet minus outlet) to the cell value of mass imbalance? <\/p>\n
<\/p>\n
the second problem, since my domain experience mass influx, but due to the compressibility (incompressible means infinite sound speed and inflow immediately will push outflow) the inflow shock (which also brings mass into the domain) is not felt by the outlet. And I realize that in each cell it might be also true that one face is experiencing inflow while the other side face might not have any outflow. Does it mean that the cell based mass convergence will never be achieved? <\/p>\n
<\/p>\n
2. So my second question is, in my problem I am getting continuity residual below 1e-7 for first couple of iteration but as soon as shock enter couple of cell distance, the continuity residuals are always in the order of, O(1) to O(10). is it acceptable? given that all other residuals remain below O(1E-6). <\/p>\n
<\/p>\n
TIA <\/p>\n","protected":false},"template":"","class_list":["post-30198","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_old_topic_id":["2367"],"_bbp_old_topic_author_name_id":["Anonymous"],"_bbp_old_is_topic_anonymous_id":["false"],"_bbp_old_closed_status_id":["publish"],"_bbp_author_ip":[null],"_bbp_old_sticky_status_id":["normal"],"_bbp_likes_count":["0","0","0","0","0"],"_btv_view_count":["3705"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["30198"],"_bbp_forum_id":["27792"],"_bbp_engagement":["22555","155230","169471"],"_bbp_voice_count":["3"],"_bbp_reply_count":["3"],"_bbp_last_reply_id":["96573"],"_bbp_last_active_id":["96573"],"_bbp_last_active_time":["2019-10-21 16:42:04"]},"test":"fuad87"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/30198","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\/30198\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=30198"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}