{"id":371859,"date":"2024-07-15T08:42:23","date_gmt":"2024-07-15T08:42:23","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/total-pressure-is-not-equal-to-the-sum-of-static-pressure-and-dynamic-pressure\/"},"modified":"2024-07-15T08:42:23","modified_gmt":"2024-07-15T08:42:23","slug":"total-pressure-is-not-equal-to-the-sum-of-static-pressure-and-dynamic-pressure","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/total-pressure-is-not-equal-to-the-sum-of-static-pressure-and-dynamic-pressure\/","title":{"rendered":"Total pressure is not equal to the sum of static pressure and dynamic pressure."},"content":{"rendered":"

When I use Ansys Fluent to calculate the total pressure drop between the inlet and outlet, I meet some questions.<\/p>\n

1. I use Mass-Weighted Average Method to check the pressure at the inlet and outlet after the calculation. However, total pressure at the outlet is higher than the inlet and this is impossible. (The settings of Fluent is shown in Figure 1.) I change the surface integrals to Area-Weighted Average or Facet Average, the problem is still exists.<\/p>\n

2. I think the total pressure at the outlet is equal to dynamic pressure because the static pressure is zero. However, further research have found that there is a big difference between total pressure and dynamic pressure. When I export the ASCII files of total pressure, dynamic pressure and static pressure, the total pressure is still not equal to the sum of the static pressure and dynamic pressure at the outlet. So I think this problem is not caused by the types of surface integrals.<\/p>\n

I want to know why total pressure of the outlet is higher than the inlet? Why total pressure is not equal to the sum of static pressure and dynamic pressure when I use pressure outlet boundary condition at the outlet?<\/p>\n

(Notes: The caculation is converged after 87 iterations. The detailed settings of fluent are shown below)<\/p>\n

<\/p>\n

Figure 1 The settings of Fluent<\/p>\n

<\/p>\n

 <\/p>\n

<\/p>\n

<\/p>\n

 <\/p>\n

Figure 2 The convergence of the calculation<\/p>\n

<\/p>\n

Figure 3 The pressure of the outlet<\/p>\n","protected":false},"template":"","class_list":["post-371859","topic","type-topic","status-closed","hentry","topic-tag-boundary-conditions","topic-tag-fluent","topic-tag-static-pressure","topic-tag-total-pressure"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_subscription":["436469","199"],"_bbp_author_ip":["185.148.13.119"]," _bbp_last_reply_id":["0"]," _bbp_likes_count":["0"],"_btv_view_count":["1125"],"_bbp_topic_status":["unanswered"],"_bbp_topic_id":["371859"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","436469"],"_bbp_voice_count":["2"],"_bbp_reply_count":["24"],"_bbp_last_reply_id":["374585"],"_bbp_last_active_id":["374585"],"_bbp_last_active_time":["2024-08-01 00:48:32"]},"test":"xukai214mail-nwpu-edu-cn"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/371859","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\/371859\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=371859"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}