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April 21, 2022, 14:18
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RPI Boiling model for mcirochannel
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#1 |
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New Member
Suraj A Bolaj
Join Date: Apr 2022
Posts: 4
Rep Power: 4  |
Hi there,
We are performing analysis on rectangular microchannel Geometry: 40mm long x 0.24mm wide x 0.5mm height Working Fluid: Water-liquid and water-vapour Models:- Multiphase: Eulerian, RPI boiling model Energy equation: on Viscous: k-epsilon, RNG, Standard wall functions, mixture. Boundary Conditions: temp=323k, Inlet velocity=0.826m/s at 1 bar pressure Outlet(pressure outlet): water liquid(temp=373.15), water vapour(temp=373.15) 3 sides wall heated(copper wall) heat flux=500kw/m^2 (bottom, left, right walls), top wall(polycarbonate Laxen) heat flux=0 Methods:- Scheme: Coupled Gradient: Least squares cell-based Pressure: Second order Momentum: Second order upwind Volume fraction: QUICK Turbulent Kinetic Energy: Second order upwind Turbulent Dissipation Rate: Second order upwind Energy: Second order upwind During Initialization I am facing an error indicating the Turbulent viscosity ratio is limited to e5 in cells..... and as the calculation proceeds the cells reduces after 500 iterations I got this error: Experiencing convergence difficulties - temporarily relaxing and trying again... Experiencing convergence difficulties - temporarily relaxing and trying again... Experiencing convergence difficulties - temporarily relaxing and trying again... Experiencing convergence difficulties - temporarily relaxing and trying again... Stabilizing pressure coupled to enhance linear solver robustness. Experiencing convergence difficulties - temporarily relaxing and trying again... Divergence detected in AMG solver: pressure coupled Stabilizing k to enhance linear solver robustness. Divergence detected in AMG solver: k Stabilizing epsilon to enhance linear solver robustness. Divergence detected in AMG solver: epsilon Stabilizing temperature to enhance linear solver robustness. Stabilizing vof-1 to enhance linear solver robustness. Divergence detected in AMG solver: vof-1 Error at host: floating point exception Error at Node 0: floating point exception ===============Message from the Cortex Process================================ Compute processes interrupted. Processing can be resumed. ================================================== ============================ Error: floating point exception Error Object: #f Registering ReportDefFiles, ("C:\Users\91960\Desktop\Major project\rectangular channel\tough assignment_files\dp0\FLU\Fluent\mass-flow-rate-rfile.out" "C:\Users\91960\Desktop\Major project\rectangular channel\tough assignment_files\dp0\FLU\Fluent\report-file-0.out") Error: WorkBench Error: Could not handle event: SolutionStatusUpdate Error Object: #f Calculation complete. Can anyone help me with this? Thank you |
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April 29, 2022, 05:27
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#2 |
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New Member
Neeraj Kumar Vidhyarthi
Join Date: Apr 2022
Posts: 4
Rep Power: 3 |
multiphase model should be used here is homogenous
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January 24, 2024, 09:07
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#3 |
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New Member
marcus aurelius
Join Date: Sep 2023
Posts: 16
Rep Power: 2 |
What is homogeneous model?
I still have fundamental question, can we use RPI wall boiling model for microchannels where the width can be as small as 0.2 mm? |
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| eulerian multiphase model, fluent, microchannel, rpi model, rpi wall boiling |
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