HydroGym

A Reinforcement Learning Platform for Fluid Dynamics Control

42+ Validated Environments | 3 Numerical Backends | Easy access

Comprehensive Flow Control Suite

From canonical 2D cylinder flows to complex 3D turbulent scenarios, HydroGym provides standardized environments for systematic RL algorithm development and evaluation.

HydroGym Environment Overview

Three Powerful Numerical Backends

Choose the right solver for your research needs—from high-performance computing to gradient-enhanced optimization

m-AIA

Lattice Boltzmann Method GPU C++

High-Performance CFD for Large-Scale Simulations

Built on RWTH Aachen's m-AIA framework, this backend enables massive parallel simulations with efficient CPU/GPU acceleration.

  • 2D & 3D turbulent flows at industrial scales covering a large range of Re numbers
  • MPI + OpenMP parallelization
  • Validated against DNS benchmarks
  • Docker containers available
Explore m-AIA Environments →

JAX

Differentiable Physics GPU JAX

Gradient-Enhanced RL with Automatic Differentiation

GPU-accelerated differentiable simulations enable gradient-based policy optimization, dramatically improving sample efficiency.

  • Automatic differentiation through flow environments
  • 2D Kolmogorov & 3D channel flows
  • Fully vectorized with jit compilation
  • 30-50% faster convergence
Explore JAX Environments →

Firedrake

Finite Element Method CPU Python

Transparent, Extensible & Customizable Python Framework

Python-based finite element solver prioritizing code clarity and research extensibility with full access to solver internals.

  • Taylor-Hood mixed elements with semi-implicit timestepping
  • Complete Python implementation
  • Easy to modify and extend
  • PETSc parallel linear algebra backend
Explore Firedrake Environments →

Example Flow Control Scenarios

Validated environments with systematic Reynolds number progressions

Cylinder Flow

Circular Cylinder

2D & 3D flows at Re=100-3,900. Drag reduction via rotation and jet actuation. Achieves >20% drag reduction.

Fluidic Pinball

Fluidic Pinball

Multi-body wake interactions at Re=30-150. Coordinated control of three cylinders demonstrates chaos suppression.

Open Cavity

Open Cavity Flow

Shear layer stabilization at Re=4,140-7,500. Acoustic feedback disruption through leading-edge control.

NACA Airfoil

NACA 0012 Airfoil

Gust mitigation at Re=100-50,000. Transverse gust encounters with load alleviation strategies.

Kolmogorov Flow

Kolmogorov Flow (Differentiable)

Extreme event mitigation in 2D turbulence. Control energy bursts and enhance mixing efficiency.

Channel Flow

Turbulent Channel (Differentiable)

Wall-shear stress reduction at Re_τ=180. Gradient-enhanced training with JAX for efficient optimization.