Wing in Transonic Flow: Aerodynamics Software Validation

The ONERA M6 wing remains a useful validation case for transonic CFD because the pressure distribution includes two distinct shock features near Section 4 at y/b = 0.8. In this study, the Stallion 3D pressure-coefficient results were compared with the published experimental measurements. The calculation reproduces the general pressure distribution and captures the location and strength of the double-shock pattern often missed by less accurate CFD solutions.

Stallion 3D uses cubes and right rectangular prisms throughout the computational domain, including the cells near the aircraft surface. Its boundary treatment allows the automatic Cartesian grid to retain its basic accuracy near complex geometry. This is important for transonic calculations, where excessive numerical smoothing can weaken or spread the shock waves over a large portion of the wing.

The pressure contours and sectional results show that a practical Cartesian-grid calculation can provide useful agreement with a standard experimental test case. The complete simulation can be prepared and run locally on a Windows 10 or Windows 11 computer without a remote HPC system. This study is one part of an ongoing evaluation of Stallion 3D for aircraft analysis and transonic aerodynamic calculations.

Future studies will examine additional validation cases and compare integrated forces, pressure distributions, and other aerodynamic quantities over a range of flight conditions.

If you know a colleague or graduate student working with transonic CFD, feel free to forward this article.

Learn more about Stallion 3D at Hanley Innovations ➡️ https://www.hanleyinnovations.com

Let me know if you have any questions. Until next time.  Thanks.

Patrick 

Patrick Hanley, Ph.D.

https://www.hanleyinnovations.com

Airfoil Tools: Aerodynamics software for analyzing isolated airfoils and multi-element airfoils in subsonic, transonic and supersonic flows

How I Developed a Suite of Airfoil Tools

Hanley Innovations airfoil software suite was developed progressively, with each new tool building on and verifying the previous step. The objective was to create a modern set of user-friendly airfoil analysis tools for engineers, designers, and students.

Step 1. Develop an airfoil analysis method using a linear-strength panel method combined with a practical stall model. This provided a fast foundation for calculating pressure distributions, lift, drag, and pitching moment over a useful range of operating conditions.

Step 2. Integrate the Step 1 solver into an interactive multi-element airfoil tool. This extended the analysis to configurations containing flaps, slats, and multiple lifting elements while retaining the speed and simplicity of the original method.

Step 3. Develop a graphical interface using an O-grid and an Euler solver based on the Van Leer flux-vector-splitting method. This provided a compressible-flow capability and allowed the panel-method results to be compared with a higher-fidelity numerical solution.

Step 4. Apply the multi-element workflow from Step 2 to an Euler solver using the Van Leer method and a Cartesian grid. The Cartesian-grid approach simplified grid generation and provided a practical path for analyzing more complicated airfoil arrangements.

Download VisualFoil NACA Free ➡️

The overall development strategy was deliberately incremental. Each stage added a new capability while providing an opportunity to verify the calculations against the earlier methods. The result is a related suite of tools covering rapid preliminary analysis, multi-element configurations, compressible flow, and Cartesian-grid CFD.

Learn more ➡️ https://www.hanleyinnovations.com

eVTOL Transition Analysis and Aerodynamics

A recent Stallion 3D study examined the NASA RAVEN-SWFT OpenVSP model as a 1,000-pound aircraft transitioning in forward flight while retaining its six vertical rotors.

The preliminary cases covered 7, 20, 40, and 60 m/s. Stallion 3D calculated aircraft lift, drag, moments, individual rotor power, total rotor power, and the aerodynamic power required to overcome drag. The resulting tables provide a simple baseline for transition as a hexacopter.

What the Initial Sweep Shows

At low speed, most of the required power is associated with the lifting rotors. As speed increases, rotor power decreases while drag multiplied by speed increases rapidly. Several rotors also begin to autorotate in edgewise flow. This indicates that a practical transition schedule must include rotor unloading, tilt, shutdown, braking, feathering, or another method of controlling the rotor state.

The all-vertical case is not presented as the optimum solution. It is a minimum-viable baseline. The next step is to vary proprotor angle, rotor grouping, aircraft attitude, and shutdown strategy. A small number of CFD cases can first identify the useful region of the design space. More expensive cloud or high-performance computing can then be applied to optimize the promising configurations rather than search blindly.

This is the gap Stallion 3D is intended to fill: establish a credible aerodynamic and propulsion plant model early, use real forces and moments to remove poor transition concepts, and reserve large computing budgets for the designs that justify further study.

View the Tables and Transition Graph

---

About Stallion 3D

Stallion 3D bridges the gap between low-fidelity panel methods and expensive CFD algorithms that run in remote data centers. It was developed to efficiently solve aerodynamic problems and deliver high-fidelity RANS solutions securely on your Windows 10/11 computer. Stallion 3D imports actual designs, automatically generates the volume grids and computes real-world solutions. Use it to verify conceptual designs across subsonic, transonic and supersonic Mach numbers.

Learn more➡️

Hanley Innovations
Stallion 3D Aerodynamics Software
www.hanleyinnovations.com

Soccer Skills: The Aerodynamics of a Bending Soccer Field Goal

Aerodynamics of a Soccer Ball Transcript

Welcome to Bend It Like Stallion 3D. The aerodynamics of a spinning soccer ball.

The colored surface represents the local flow speed around the ball, while the streamlines show how rotation changes the wake behind the ball. Because the ball is spinning, the air flow becomes asymmetric, producing a pressure difference across the surface. This pressure difference generates a lateral force that curves the trajectory during flight.

In this example, we examine the aerodynamics of a regulation soccer ball traveling at 67 mph. The ball is spinning at 600 revolutions per minute or 10 hertz to produce a side force across the soccer pitch.

The purpose of the simulation is to predict the Magnus effect and figure out the magnitude responsible for a bending free kick.

• To start the simulation in Stallion, we import the STL file of the ball.
• Next, we set the speed, flight angle, and sea level conditions.
• Then, we set the rate of rotation to 10 herz and the normal vector to the desired spin direction.
• Finally, we click the menu to generate the grid and solve the flow.

For this case, Stallion 3D predicted approximately 5.8 Newtons of drag and 5.7 Newtons of side force. These values are consistent with the expected aerodynamic behavior of a spinning soccer ball and demonstrate the software's ability to capture rotational flow effects.

Surface pressures, force components, and aerodynamic moments are computed directly from the Navier Stokes solution. Although this example features a soccer ball, the same numerical methods are used to analyze aircraft, UAVs, rockets, and EV2L vehicles, and of course, a real football as well 😀  By changing the geometry and the operating conditions, Stallion 3D can predict the aerodynamic forces and moments required for engineering design and stability analysis.

Please visit https://www.hanleyinnovations.com to learn more about Stallion 3D

Bend it like Stallion 3D. FIFA Inspired Aerodynamics Simulation ⚽🥅

 

A soccer ball was simulated in Stallion 3D at 67 mph (30 m/s) with 600 rpm (10 Hz) of spin to examine the Magnus effect responsible for a bending free kick.

The  Stallion 3D simulation predicted the following forces:
• Side Force: 5.72 N (1.29 lb)
• Total Drag: 5.70 N (1.28 lb)
• Lift: −0.333 N

The streamlines, in the attached side-view picture, show the wake generated by the spinning ball, producing the lateral force that curves the trajectory.  Although simple in appearance, predicting this behavior requires resolving the interaction between boundary-layer separation, rotation, and wake development around the ball.  Similar dynamic inputs into Stallion 3D are often used to accurately compute dynamic and damping derivatives for airplane, UAVs and eVTOLS stability and control. 

Sometimes CFD predicts an aircraft. Sometimes it predicts a free kick.

Learn more ➡️ https://www.hanleyinnovations.com

eVTOL Aerodynamics: Use Stallion 3D for Early eVTOL Concept Analysis. Compute lift, drag, moments and ideal power

This is a Stallion 3D near-hover simulation of the NASA RAVEN SWFT, a 1,000 lb eVTOL concept, at 7 m/s forward speed. The model includes six lifting rotors with pressure plotted on the aircraft surfaces and actuator disks. The pressure scale shown is approximately 100,950 to 101,450 Pa.

The computed surface forces are: lift = -86.31 N (-19.40 lbs), side force = -3.08 N (-0.693 lbs), pressure drag = 57.65 N (12.96 lbs), friction drag = 4.65 N (1.04 lbs), and total drag = 62.30 N (14.01 lbs). The related force components are FX = 57.65 N, FY = -3.08 N, and FZ = -86.31 N. The moments about the reference CG are pitch = 175.38 N-m, roll = -1.23 N-m, and yaw = -9.74 N-m.

The ideal rotor power from the six disks is 7,059.38 W, 7,065.66 W, 6,310.21 W, 6,314.22 W, 10,189.09 W, and 10,231.14 W, for a total ideal power of 47,169.70 W. This is a simple near-hover CFD check, but it shows the type of integrated aircraft, rotor, pressure, force, moment, and power information that can be reviewed directly inside Stallion 3D.

Performing early 3D aerodynamics analysis using accurate and accessible software ensures stable first flights. 

Please use the link be low to learn more about Stallion 3D.

➡️ https://www.hanleyinnovations.com 

Learn the Background Story about my CFD and Aerodynamic Software Business

 

I recently had the chance to talk with Roopinder at ENGtechnica on YouTube about aerodynamics, CFD, and some of the practical work behind Hanley Innovations.

The discussion is a good plain-English overview of how I think about simulation, aircraft design, and engineering software. It is a technical conversation about real aerodynamics, useful calculations, and the role of CFD in understanding what an aircraft actually sees.

Please let me know if you have any questions. 

To learn more about Hanley Innovations please visit https://www.hanleyinnovations.com.

Best regards,

Patrick.