Pixel Wind Tunnel vs ViscousJoukowski

Draw a shape. Tap Simulate. Watch real fluid dynamics come alive in pixels. Pixel Wind Tunnel is a 2D fluid simulation app that runs real CFD (Computational Fluid Dynamics) calculations right on your device. No simplified approximations — the app solves the incompressible Navier-Stokes equations using the CIP advection method and Pressure Poisson solver, the same mathematical framework used in professional engineering software. HOW IT WORKS Draw any shape with your finger — airfoils, cars, buildings, anything Tap Simulate Watch the flow develop in real time That's it. Real fluid physics in three steps. SEE THE FLOW Switch between visualization modes to explore different aspects of the physics: • Velocity — where the flow speeds up and slows down • Pressure — high and low pressure regions around your shape • Vorticity — spinning structures and vortex shedding • Streamlines — paths that fluid particles follow MEASURE PERFORMANCE Real-time aerodynamic coefficients calculated from surface pressure and viscous stress integration: • Drag coefficient (Cd) • Lift coefficient (Cl) • Reynolds number Draw two different shapes and compare which one has less drag. Understand why streamlined shapes work better — with real numbers, not guesswork. EXPLORE DEEPER • Place point probes anywhere to track velocity and pressure over time • Scrub through simulation history with the timeline slider • Adjust inlet velocity and viscosity to change flow conditions • Save shapes with screenshots and reload them anytime REAL CALCULATION, NOT AN ANIMATION Every frame you see is computed from the actual Navier-Stokes equations. The CIP (Cubic Interpolated Propagation) method handles advection with minimal numerical diffusion, while the SOR iterative solver resolves the pressure field. Boundary conditions, viscous forces, and flow separation are all physically modeled. FOR CURIOUS MINDS Whether you're a student studying fluid mechanics, an engineer sketching quick ideas, a teacher demonstrating aerodynamics in class, or simply someone who wonders why things are shaped the way they are — draw it and find out.

Are you interested in fluid dynamics? Viscous Joukowski simulates the flow around a Joukowski airfoil by solving the two-dimensional incompressible Navier–Stokes equations directly on your device. For teachers, students, and curious aerodynamicists, it provides an interactive way to explore how viscosity changes lift, drag, pressure, boundary layers, separation, and wake formation. Watch vorticity, speed, pressure, and streamlines evolve around the airfoil. Change the angle of attack, thickness, and camber by dragging directly on the flow field, or use precision controls. Adjust the Reynolds number to explore steady flow, separated wakes, starting vortices, and vortex shedding. Surface-pressure curves and aerodynamic-force estimates update as the simulation develops. The app also includes the classical analytical Joukowski potential-flow solution. Overlay it on the computed viscous pressure distribution to see where the ideal textbook model agrees with—or departs from—the Navier–Stokes result. In the potential solution, circulation is selected using the Kutta condition; in the viscous simulation, circulation and the wake develop dynamically from the no-slip flow. All calculations run locally using Apple MLX and GPU-accelerated Fourier methods. No server, account, or cloud computation is required.