Convection–Diffusion, Transient Simulation| Stability & Gnuplot: Hands-on OpenFOAM (Tutorial 09)

In this session, we focus on the numerical foundations of CFD simulations in OpenFOAM, with special emphasis on convection–diffusion processes, transient simulations, and stability considerations. The lecture bridges theory and practice, helping users understand how numerical schemes influence accuracy, stability, and convergence in real OpenFOAM cases.

Instructor: Dr. Abishek (IIT Bombay)

📌 What You Will Learn:

🔷 Convection & Diffusion Terms

Physical meaning of convection and diffusion in transport equations

Discretization of convection and diffusion terms in OpenFOAM

Impact of numerical schemes on accuracy and stability

🔷 Transient Simulation

Formulation of transient governing equations

Time discretization approaches in OpenFOAM

Role of time-step size and Courant number

🔷 Stability Considerations

Stability constraints in transient CFD simulations

Explicit vs implicit treatment of terms

Practical guidelines for stable and efficient simulations

🔷 Implicit Schemes

Concept of implicit discretization

Advantages over explicit schemes

How implicit schemes are implemented in OpenFOAM

🔷 Post-Processing with Gnuplot

Using Gnuplot for data visualization

Plotting residuals, field values, and time histories

Interpreting numerical results for validation and analysis

🎯 Who Should Watch?
CFD students, researchers, and OpenFOAM users who want a deeper understanding of numerical methods, transient simulations, and stability issues in CFD.

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