LSPIV vs Pixel Wind Tunnel

LSPIV (large-scale particle image velocimetry) is an image-based method for measuring velocity distribution on the water surface. Applications of LSPIV have been increasing for both field and laboratory experiments as unique and powerful tools for non-intrusive velocimetry using conventional imaging devices and specialized image processing software. This app utilizes a smartphone to implement LSPIV. By innovatively combining the sensors embedded in smartphones, the images captured with them can be intrinsically and instantly ortho-rectified without making recourse to GCPs. The app was developed under support by the River Fund in charge of the Foundation of River and Watershed Environment Management (FOREM), Japan; Grant-in-Aid for Young Scientists (B); and the Research Fund of Japan Institute of Country-ology and Engineering.

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.