Solved by Default 🛠️ — Import • Mesh • Solve in Stallion 3D
A quick walkthrough by Dr. Patrick Hanley (Hanley Innovations)
Click the image to watch the short demo on YouTube.
In this quick demo, we import a drone STL, let Stallion 3D auto‑configure the CFD boundaries and domain sizing, pick a sensible default mesh, and run the solver—going from geometry to pressure contours in minutes.
What the video covers
Import geometry via Design → Import STL (ASCII or binary). Set units (e.g., meters) and position/orientation.
Automatic domain & boundaries: Stallion 3D sizes the CFD box and boundary conditions from the STL—so you don’t have to hand‑tune the grid extents.
Optional geometry quality check: If your STL has gaps/holes, run the quick check to mitigate issues before grid generation.
CFD setup with smart defaults:
choose a mesh density (Quick, Medium, Large; example shown: ~1 M cells). The default solver and domain dimensions are good starting points.
Generate & solve: Start meshing and the flow solution in one click.
Visualize results: View the 3D geometry and pressure distribution; add legends/units (Pascals) with the graph options.
Why this workflow is fast
No manual domain sizing—it’s solved by default.
Defaults that “just work” for early design checks.
Applies across subsonic, transonic, and supersonic regimes for rapid concept iteration.
How they work for aircraft takeoff/landing, motorsports downforce,
and how they are designed by engineers.
Quick definition
A multi-element airfoil is a lifting surface made from two or more cooperating profiles—typically a
main element plus leading-edge slats and/or trailing-edge flaps. By carefully positioning the
elements (gaps, overlaps, and deflections), designers dramatically increase lift (for aircraft) or downforce (for cars)
at low to moderate speeds without making the wing excessively large.
Why multi-element airfoils work
Circulation & camber boost: Slats and flaps increase effective camber, strengthening circulation and lift.
Slot effect (boundary-layer control): The gap between elements jets high-energy air over the next element, delaying separation and letting the system reach higher lift coefficients before stalling.
Fowler motion: Many flaps translate rearward and rotate, increasing wing area and camber simultaneously.
Load sharing: Each element carries part of the pressure jump, reducing peak adverse gradients on any single surface.
In practice, a single-element airfoil might achieve a CL,max around ~1.4 (order of magnitude), while a well-designed multi-element system
can exceed ~2.5–3.0+ depending on geometry, Reynolds number, and deflection schedule. (For cars, think of “negative lift”
or downforce rather than positive lift.)
Where you see them in the real world
Jet airliners (takeoff & landing)
Airliners need huge lift at low speeds to operate from practical runways. On approach and takeoff, they deploy
leading-edge slats and multi-segment trailing-edge flaps to raise CL,max, allowing lower approach
speeds, shorter distances, and improved safety margins. In cruise, devices retract to reduce drag.
Business jets, turboprops, and STOL aircraft
Many business jets and turboprops use slats and flaps for field performance. Short-takeoff-and-landing (STOL) aircraft
do the same, sometimes adding devices like fences, cuffs, Krueger flaps, or blown flaps to energize flow
and improve controllability near stall.
Uncrewed aircraft & model aviation
UAVs benefit from high-lift systems for heavier payloads or shorter fields. Multi-element tails or deployable flaps are
common on fixed-wing drones that must launch and recover in tight spaces.
Motorsports & performance cars
Racing wings often use two or more elements (plus Gurney flaps) to produce large downforce at modest speeds,
improving grip in braking and cornering. Rules usually cap element count and geometry, so careful design of slot gap,
overlap, and flap angle is crucial to hit the aero targets without stalling the wing.
Key design choices
Architecture: How many elements? Slat + single flap, double-slotted flap, or more?
Gap & overlap: Tiny changes (millimeters) in the slot can make or break high-lift performance.
Deflection schedule: Angle and translation vs. speed/phase (takeoff vs. landing) or, for cars, vs. ride height/attitude.
Reynolds/Mach effects: Section choice and flap geometry depend on size and speed regime.
3D integration: Wing twist, endplates/fences, tip effects, and flap track fairings all matter.
Structures & mechanisms: Added complexity, weight, and maintenance vs. performance gains.
Noise & certification: For aircraft, aero-acoustic considerations can drive geometry and schedules.
A practical workflow for designing multi-element airfoils
Define the mission: Field length, stall margins, approach/takeoff speeds (aircraft), or target downforce/drag window (cars).
Choose a baseline section: Start with a main element suited to the Reynolds number and thickness needs.
Select devices: Slat type and size; flap type (plain, split, single-slotted, double-slotted, or Fowler); Gurney height.
Set initial geometry: Gap/overlap and hinge lines; add mechanical constraints for real deployable hardware.
Analyze 2D performance: Sweep angles of attack and device deflections to map CL, CD, Cm, and stall behavior.
Scale to 3D wing/car installation: Include spanwise effects, endplates/fences, and local ground effect (cars).
Optimize the schedule: Create “takeoff” and “landing” (or “low-speed” and “high-speed”) settings; validate against constraints.
Iterate with CFD and tests: Refine details such as slot curvature, fairings, and sealing strategies.
Design faster with Hanley Innovations software
Hanley Innovations provides tools that streamline multi-element airfoil and wing design—from early concepts to practical,
test-ready geometries:
MultiElement Airfoils – Rapidly configure slats, flaps, gaps, and overlaps; evaluate high-lift performance across
deflection schedules. Ideal for airliner high-lift studies, STOL concepts, UAVs, and motorsports wings.
3DFoil – Analyze full wings and tail combinations quickly, explore stability derivatives, and build trim maps that
incorporate your high-lift settings.
Stallion 3D – Move to full-3D CFD when you need richer flowfield details (pressures, forces/moments, and flow features)
on real geometries, including multi-element systems and car wings.
Ready to accelerate your high-lift or downforce project?
How many elements are “too many”?
Diminishing returns set in as mechanical complexity, drag, and sensitivity increase. Most practical systems use one slat and
one or two flap elements; motorsports rules often limit element count explicitly.
Do Gurney flaps count as an element?
They’re typically treated as a device on an element rather than a full element, but they can significantly boost
lift/downforce at the right Reynolds numbers.
What’s the most sensitive parameter?
The slot (gap and overlap) and the deflection schedule. Small tweaks here can change peak performance and stall character.
🚀 Rocket Aerodynamics — From STL to Flight-Ready Insights
Altitude is great—but control and stability win flights. In this video, I show how to take your rocket’s STL file and run a complete CFD analysis in Stallion 3D so you can predict side force, spin tendency, and CP shift before launch.
What’s inside
Import your STL from OpenVSP, Tinkercad, or OpenRocket
Set realistic flight conditions: Mach, altitude, angle of attack
Run the solver to get surface pressure, side force, yaw moment, spin tendency, and CP shift
Why it matters
Estimates for CG/CP are a start, but they miss critical effects—fin misalignment, transonic bumps, and asymmetric forces. Stallion 3D gives you the full aerodynamic picture so launches are straighter, faster, and more reliable.
Unlocking Aerodynamic Excellence with Hanley Innovations Airfoil Tools
Engineers, hobbyists, and researchers—if precision airfoil analysis and design are on your radar, Hanley Innovations offers a powerhouse suite of tools. Here’s a deep dive into their flagship offerings:
VisualFoil 5 (VF50) is a powerful airfoil analysis and design tool for Windows, ideal for anything from wings and spoilers to hydrofoils and rudders. It combines:
Linear-strength vortex panel method + boundary-layer solver + stall model for Cl, Cd, and Cm vs. AoA
Built‑in NACA 4/5/6‑digit generators and UIUC database import
Streamline & pressure-field visualization, along with exportable tables and graphs
High‑precision plotting and printing utilities
The software has been validated against experimental data (e.g., NACA 0012, 2412, SD7003 at various Reynolds numbers) demonstrating accurate lift, drag, and stall predictions
This CAE tool calculates aerodynamic interaction between single or multiple airfoils—perfect for flaps, slats, spoilers, F1-style rear wings, or hydrofoil sets.
Solves compressible Euler & Navier‑Stokes for up to 20 elements
Includes vortex panel + boundary‑layer solver
Automated mesh-free flow analysis with pressure/Mach/temperature visualization
Exports DXF, CSV, and detailed performance plots
The software is ideal for applications like F1 DRS wings, multi-element turbines, and icing studies.
Aimed at extracting coordinate data from images, this Windows‑based tool converts JPG, GIF, BMP, PNG, TIFF into DXF, UIUC, or VisualFoil formats.
Tailored for airfoil leading/trailing edge and curvature accuracy
Workflow-ready for CFD, CAD, or manufacturing
Supports fonts from scanned journals, textbooks, online images and even iced‑airfoil cases :
Why These Matter
This toolkit covers your entire airfoil design pipeline:
Digitize – Capture precise real-world or experimental shapes
Analyze – Use VisualFoil for 2D performance; MultiElement for interacting surfaces
Validate – Compare with real data and export polished reporting
Whether you're developing UAV wings, race-car spoilers, hydrofoils, or ice-accretion analysis, Hanley’s software is robust, validated, and research-grade. Ready to elevate your aerodynamic workflow?
Stallion 3D is our flagship computational fluid dynamics software that simplifies complex aerodynamics for engineers, educators, and designers.
Subsonic Flow Simulation
Whether you're analyzing a general aviation aircraft or a drone, Stallion 3D handles subsonic flows with speed and accuracy.
You can quickly visualize streamlines, pressures, and forces with just a few inputs—no external grid generators required.
Transonic Flow Simulation
In the transonic regime, where shock waves and compressibility effects become critical, Stallion 3D shines.
It solves the full compressible Navier-Stokes equations with turbulence modeling to capture shock interactions and wave drag.
Supersonic Flow Simulation
And for supersonic flows, Stallion 3D gives you direct insight into shock structures, flow separation, and surface heating—crucial for high-speed design and innovation.
Why Stallion 3D?
Stallion 3D puts the power of CFD in your hands—no need for external meshing or scripting.
Subsonic, transonic, or supersonic—it’s one tool for the entire speed envelope.
Digitizing Iced Airfoils with Airfoil Digitizer ❄️✈️
Accurately modeling the effects of ice accretion on airfoils is essential for understanding performance degradation in real-world flight conditions. At Hanley Innovations, we make this possible with Airfoil Digitizer — a powerful and easy-to-use tool that lets you convert complex airfoil images, including those with icing, into precise coordinate files.
The image demonstrates a real-world use case: a NACA 0012 airfoil with upper-surface ice accretion digitized using Airfoil Digitizer. The original airfoil and the iced version are both captured from the image and converted into coordinate data for use in aerodynamic analysis tools such as VisualFoil, Stallion 3D, or even your own custom CFD code.
Why Use Airfoil Digitizer for Iced Airfoils?
Handles Irregular Shapes: Ice accretion rarely forms smooth contours — our tool adapts to jagged and asymmetric formations.
Adjustable Tolerance: Capture just the right amount of detail using the built-in tolerance slider.
Output in Analysis-Ready Format: Export coordinates directly to VisualFoil, UIUC, or DXF format for quick analysis.
No Need for Manual Tracing: Save time and reduce error when extracting data from icing simulation or wind tunnel images.
Whether you're working on aircraft certification, research, or student projects, Airfoil Digitizer makes it easy to extract the effects of ice accretion for aerodynamic simulation and performance prediction.
