Hi,
I am modeling a transient flow through a straight flexible pipe in Fluent. I got the experimental data: time-varying velocity at inlet, time-varying pressure at the inlet, time-varying pressure at the outlet.
I have to decide what fluid boundary condition to use. The time-variance is realized by the UDF define_profile.<\/p>\n
I tried with the velocity-inlet and pressure-outlet. I monitor the calculated inlet pressure, and it differs very much from the experimental data – it is almost equal to the imposed pressure at the outlet.
So I tried with the pressure-outlet and pressure-inlet BC, where for the inlet I calculated the total pressure (static pressure+dynamic pressure, anyway dynamic pressure was negligible). In such model I got much discrepancies in calculated velocity at the inlet and measured velocity.<\/p>\n
So the question arises, how to properly specify the boundary conditions for this problem.
I found that in the pressure outlet panel, there is an option “target mass flow”, where I can specify the time-varying mass flow, determined based on the measured velocity time profile. Is this a proper solution? The measured velocity however, is at the inlet, not at the outlet… and they will not be equal because there is a mass accumulation in the domain.<\/p>\n
The best solution for me, will be to impose: at the inlet both the velocity and pressure time profile, and at the outlet, the pressure time profile. However as far as I know there is no possibility to impose both velocity and pressure at the inlet, and I don’t know why.<\/p>\n
Please guide me with this problem,
Regards<\/p>\n","protected":false},"template":"","class_list":["post-364056","topic","type-topic","status-closed","hentry"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["70859","199"],"_bbp_author_ip":["23.206.193.154"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["254"],"_bbp_topic_status":["unanswered"],"_edit_lock":["1714000647:290367"],"_bbp_topic_id":["364056"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","70859"],"_bbp_voice_count":["2"],"_bbp_reply_count":["7"],"_bbp_last_reply_id":["364397"],"_bbp_last_active_id":["364397"],"_bbp_last_active_time":["2024-04-26 12:30:37"]},"test":"marcin-nowak1pg-edu-pl"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/364056","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":1,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/364056\/revisions"}],"predecessor-version":[{"id":364057,"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/364056\/revisions\/364057"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=364056"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}