{"id":463238,"date":"2026-09-03T16:21:39","date_gmt":"2026-09-03T16:21:39","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/continuity-residual-remain-around-10e-01-in-2d-steady-fluent-simulation\/"},"modified":"2026-09-03T16:21:39","modified_gmt":"2026-09-03T16:21:39","slug":"continuity-residual-remain-around-10e-01-in-2d-steady-fluent-simulation","status":"publish","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/continuity-residual-remain-around-10e-01-in-2d-steady-fluent-simulation\/","title":{"rendered":"Continuity residual remain around 10E-01 in 2D steady Fluent Simulation"},"content":{"rendered":"

Hello,<\/p>\n

I am running a 2D steady-state internal flow simulation in ANSYS Fluent 2026 R1<\/strong> for a turbine-blade internal cooling study. The model contains a main air region and four porous regions. I am using the SST k−ω<\/span><\/strong> turbulence model with the energy equation enabled.<\/p>\n

My main problem is that the continuity residual decreases initially but then remains nearly flat at approximately 10E-01<\/span><\/strong>, while the other residuals continue to decrease.<\/p>\n

I also monitor pressure during the calculation. The pressure-related monitor continues to increase with iteration instead of reaching a stable plateau, so I do not consider the solution converged yet.<\/p>\n

I would like to understand:<\/p>\n

    \n
  1. What are the most likely reasons for the continuity residual remaining around 10E-01<\/span> when the velocity, turbulence, and energy residuals have decreased significantly?<\/li>\n
  2. Is reducing the momentum under-relaxation factor an appropriate approach, or should I focus instead on boundary conditions, mass imbalance, pressure-velocity coupling, or mesh resolution?<\/li>\n
  3. What additional quantities should I check to determine whether the problem is numerical or whether the flow may be inherently unsteady?<\/li>\n<\/ol>\n

    I have attached screenshots of the residual history, mesh, and mesh-quality statistics. I can also provide the boundary-condition and solver-setting screenshots if needed.<\/p>\n

    Thank you for any suggestions.<\/p>\n

    \"\"<\/p>\n

    \"\"<\/p>\n","protected":false},"template":"","class_list":["post-463238","topic","type-topic","status-publish","hentry","topic-tag-2d-cfd-1","topic-tag-ansys-cfd-1","topic-tag-continuity-residuals-1"],"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