OpenFOAM Tutorial – Chapter 2 (Part 14): Change Reynolds Number by Editing Viscosity скачать в хорошем качестве

OpenFOAM Tutorial – Chapter 2 (Part 14): Change Reynolds Number by Editing Viscosity

In Chapter 2 (Part 14), we learn a super practical CFD skill: how to change the Reynolds number in OpenFOAM — which, for this tutorial, means changing the kinematic viscosity (ν). We create a new case, clean it, reduce viscosity to increase Re, then restart from an already converged solution to save time and keep the run stable. What you’ll learn in this video ✅ 1) Create a new case folder (high Reynolds case) We duplicate the original cavity case using cp -r and name it something like: cavityHighRe ✅ 2) Clean the case (remove old time folders + logs) We delete unnecessary output folders (e.g., 0.1, 0.2, …) and log files so the case is fresh for the new run. ✅ 3) Increase Reynolds number by reducing viscosity (ν) Using the relation: Re = U·L / ν If we want Re ≈ 10× larger, we make ν ≈ 10× smaller: nu: 0.01 → 0.001 File location: constant/transportProperties ✅ 4) Start from a converged solution (copy time folder 0.5) Instead of starting from 0/, we copy the 0.5 time folder from the original cavity case into the new high-Re case to get a strong initial condition and faster convergence. ✅ 5) Use startFrom latestTime in controlDict We set: startFrom latestTime (so OpenFOAM starts at 0.5 automatically) endTime 2 (continue the run until 2 seconds) ✅ 6) Run icoFoam (optionally with a log file) We run from 0.5 → 2.0 and observe stable behavior with low iteration counts (a sign of good convergence). Keywords (copy/paste) OpenFOAM, icoFoam, cavity tutorial, Reynolds number, viscosity, kinematic viscosity, nu, transportProperties, constant/transportProperties, high Reynolds number, startFrom latestTime, controlDict, restart simulation, copy time folder 0.5, CFD tutorial, OpenFOAM beginner course Hashtags #OpenFOAM #CFD #icoFoam #ReynoldsNumber #Viscosity #transportProperties #OpenFOAMTutorial #CFDTutorial #EngineeringSimulation