Pixel Wind Tunnel
Pocket Size CFD
Free · Designed for iPad. Not verified for macOS.
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.
Ratings & Reviews
- This app hasn’t received enough ratings or reviews to display an overview.
- New lattice Boltzmann solver: faster and stable even at very high Reynolds numbers
- 3D mode: extrude your 2D shape in depth and orbit the camera with two fingers, with 3D streamlines
- Turbulence: LES model, inlet turbulence and a turbulence display mode
- Grid scales with your screen; drawings keep their shape when rotating the device
- Brush with adjustable size, straight lines with X/Y lock, pinch-to-zoom drawing
- Choose 1000-5000 steps; the step counter now runs through the whole simulation
- Improved iPad layout and more accurate drag and lift coefficients
- Banner ads support the app
The developer, Hiroki Kijima, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Used to Track You
The following data may be used to track you across apps and websites owned by other companies:
- Location
- Identifiers
- Usage Data
Data Not Linked to You
The following data may be collected but it is not linked to your identity:
- Location
- Identifiers
- Usage Data
- Diagnostics
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Hiroki Kijima
- Size
- 22.2 MB
- Category
- Education
- Compatibility
Requires iOS 15.0 or later.
- iPhone
Requires iOS 15.0 or later. - iPad
Requires iPadOS 15.0 or later. - iPod touch
Requires iOS 15.0 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
4+
- 4+
- Contains
Advertising
- Copyright
- © Hiroki Kijima