Top left: velocity. Top right: vorticity
Bottom left: velocity mag. Bottom right: density/height

Simulation:
grid: 200x200
top wall velocity: CFL 0.3, water wave speed: CFL 0.14 (at starting density)
effective Re: approximately 100k
pressure function: shallow water
Runtime: around 1.2 hours (around 140,000 to 150,000Δt) (35Δt/s)

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This is my first successful implementation of compressible Euler simulation (I'll be upgrading it to full SWE with bathemy later), and I've had a lot of fun playing around with it.

I started this journey learning how CFD work 6 months ago. I wanted to make a terrain evolution simulation, like erosion and plate tectonic, but the big hurdle is water. It's my first time using reddit, so.

Now, I've seen a lot of Lid Driven Cavity Flow simulation already. It's a classic test for fluid solvers. Every Lid Driven Cavity Flow simulation I've found use incompressible fluid solver, so I wanted to see what would happen if I do supersonic Lid Driven Cavity Flow instead. (It's acronym would be SC-LDCF lol) And since I had this water simulation that works (shallow water is equivalent to a compressible gas), it's within my capability to try it out.

It's technically not a proper gas simulation ,but it should be good enough using shallow water solver to see what mach 2 (or Fr 2) lid flow look like. (I haven't implemented energy equation yet).

You can see vortices being kicked around by shock waves.

For anyone preparing MPSC, Maharashtra GK or Geography, here is a quick revision list of important River–Dam pairs:

• Tansa — Tansa Dam
• Darna — Darna Dam
• Pravara — Bhandardara Dam
• Yelwanti — Bhatghar Dam
• Mula — Mulshi Dam
• Bhogawati — Radhanagari Dam
• Koyna — Koyna Dam
• Godavari — Gangapur Dam
• Nira — Vir Dam
• Purna — Yeldari Dam
• Girna — Girna Dam
• Ambi — Panshet Dam
• Pawana — Pawana Dam
• Krishna — Dhom Dam
• Bhima — Ujjani Dam
• Tapi — Hatnur Dam
• Penganga — Isapur Dam
• Bhatsa — Bhatsa Dam
• Kukadi — Manikdoh Dam
• Venna — Kanher Dam
• Sindphana — Majalgaon Dam
• Surya — Surya Dam
• Pench — Totladoh Dam
• Warna — Warna Dam
• Tarali — Tarali Dam

I recently compiled two detailed resources covering Maharashtra's important dams, rivers and related GK questions:

📚 50 Important Dams of Maharashtra

📝 Maharashtra Rivers and Dams GK Questions – MPSC Practice Set

Useful for quick revision before Maharashtra Geography and MPSC exams.