CFD Results - How to Interpret an Aerodynamic Analysis

For more information on how to process CFD data in paraview (free software): https://youtu.be/kczZPc4M-ms In this video, we explain how to interpret a typical CFD simulation report. The topic is a car and we will learn how to: - Understand the different forces & moments We analyze the drag force, lift force, lateral force as well as the pitch roll and yaw moments. The forces are then used together with the frontal surface area to calculate the drag coefficient of the car. - Detect sources of drag The iso-surface of the total pressure for a value of 0 is a good 3D representation of where you are 'losing energy', or dragging air along, or creating a wake. Typically this happens around the wheels, A-pillar, front splitter, door handles, etc. - Read surface pressure & friction maps The aerodynamic pressure map provides useful information on where the air is impacting the object, and where it is speeding up to go around curvatures. This can be useful to determine suitable locations for radiator inlet and outlet, to analyze the performance of aerodynamic elements such as rear wings, front splitters, etc. The friction map can be used to spot areas of flow separation, as low friction usually indicates detached flow (unless it's an area of flow stagnation). The surface streamlines also help to understand the local flow direction. - Analyse 3D streamlines Aerodynamic streamlines around the object help to visualize vortex structures, the scope of impact on the surrounding air etc. - Interpret sections of velocity & pressure Looking at sections of velocity & pressure helps to understand how the air curves around local parts of the geometry (suspension parts etc), how much it accelerates, what the wake looks like etc. - Localize sources of wind noise The results shown are not based on a full acoustic simulation but on an acoustic analogy, which is a mathematical translation of turbulent kinetic energy into noise energy. It doesn't provide the user with any frequency or absolute sound level results, it simply serves as a rough indication of the biggest wind noise sources. ----------------------------------------------------------------------------------------------------------- The AirShaper videos cover the basics of aerodynamics (aerodynamic drag, drag & lift coefficients, boundary layer theory, flow separation, reynolds number...), simulation aspects (computational fluid dynamics, CFD meshing, ...) and aerodynamic testing (wind tunnel testing, flow visualization, ...). We then use those basics to explain the aerodynamics of (race) cars (aerodynamic efficiency of electric vehicles, aerodynamic drag, downforce, aero maps, formula one aerodynamics, ...), drones and airplanes (propellers, airfoils, electric aviation, eVTOLS, ...), motorcycles (wind buffeting, motogp aerodynamics, ...) and more! For more information, visit www.airshaper.com