{"id":160656,"date":"2021-07-24T09:02:05","date_gmt":"2021-07-24T09:02:05","guid":{"rendered":"\/forum\/forums\/topic\/how-to-deal-with-non-convergence-while-simulating-compressible-flow-inside-an-aerospike-nozzle\/"},"modified":"2021-07-26T13:41:06","modified_gmt":"2021-07-26T13:41:06","slug":"how-to-deal-with-non-convergence-while-simulating-compressible-flow-inside-an-aerospike-nozzle","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/how-to-deal-with-non-convergence-while-simulating-compressible-flow-inside-an-aerospike-nozzle\/","title":{"rendered":"How to deal with non-convergence while simulating compressible flow inside an aerospike nozzle?"},"content":{"rendered":"
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Problems I am facing:<\/p>\n

1. Reverse flow at the outlet (I tried extending the domain, but to no avail.)<\/p>\n

2. Maximum temperature\/ pressure limited in….<\/p>\n

3. Solution not converging, particularly the residual for continuity. Other residuals also take a lot of iterations for converging<\/p>\n

<\/p>\n<\/p>\n

Kindly find the details of the set-up here:<\/p>\n

1. Steady State, Density-based, Axis-symmetric<\/p>\n

2. Spalart Allmaras Turbulence Model with energy eqn on<\/p>\n

3. Air modeled as ideal gas with Sutherland model of viscosity<\/p>\n

4. BCs: (i) Pressure inlet, Gauge Total Pressure = (NPR*101325 – 101325) ; Supersonic\/ initial Gauge Pressure = 5 Pa less than the total pressure; Total Temperature = 300 K.<\/p>\n

(ii) Pressure outlet, Gauge Pressure = 0 Pa, Total Temperature = 300 K<\/p>\n

(iii) Temperature of 300 K applied at walls<\/p>\n

(iv) Operating Pressure = 101325 Pa<\/p>\n

<\/p>\n

<\/p>\n<\/p>\n

Details regarding mesh:<\/p>\n

Structured mesh with 2,52,958 cells.<\/p>\n

Avg. element quality = 0.79571, Min. element quality = 0.28747<\/p>\n

Avg. skewness = 1.2058e-002, Max skewness = 0.35188<\/p>\n

Avg. aspect ratio = 2.0994, Max aspect ratio = 6.7975<\/p>\n

Avg. orthogonality = 0.99705, Min orthogonality = 0.85175<\/p>\n

<\/p>\n<\/p>\n

Kindly help me on this. I am also attaching the pictures of domain and mesh being used for the simulation.<\/p>\n

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\n\"Domain.PNG\"
\n<\/a><\/p>\n","protected":false},"template":"","class_list":["post-160656","topic","type-topic","status-closed","hentry","topic-tag-compressible-flow-air-2","topic-tag-supersonicflow-2"],"aioseo_notices":[],"acf":[],"custom_fields":[{"0":{"_bbp_author_ip":[""],"_bbp_old_reply_author_name_id":["Anonymous"],"_bbp_old_is_reply_anonymous_id":["false"],"_btv_view_count":["459"],"_bbp_likes_count":["0"],"_bbp_topic_status":["unanswered"],"_bbp_status":["publish"],"_bbp_topic_id":["160656"],"_bbp_forum_id":["27792"],"_bbp_engagement":["199","213483"],"_bbp_voice_count":["2"],"_bbp_reply_count":["1"],"_bbp_last_reply_id":["186601"],"_bbp_last_active_id":["186601"],"_bbp_last_active_time":["2021-07-26 13:41:06"]},"test":"ankitjaiswal-mec18itbhu-ac-in"}],"_links":{"self":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/topics\/160656","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\/160656\/revisions"}],"wp:attachment":[{"href":"https:\/\/innovationspace.ansys.com\/forum\/wp-json\/wp\/v2\/media?parent=160656"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}