Why Star-CCM+ ?

Don’t Just Simulate, Innovate!

Aerodynamics Simulation Software

Key Requirement of Aerodynamic Simulation for Performance Engineering

1. Complex Geometry Handling

• Tight link to CAD programs for direct import of geometry and parameterization
• Integrated capability for clean-up of CAD-based surfaces to retain high aerodynamic surface quality

A common theme of aerospace performance engineering is the need for high throughput. The first step of that process is importing geometry and any solution that does not provide this ability is a significant time sink. The next step in complexity, and where most companies want to operate, is being able to bring in the full parameterization. This opens up the possibilities for design space exploration as well as eliminating the slow back-and-forth between CFD & CAD engineers trying to agree on a proper format. 

2. Robust and Precise Meshing

• Robust and automated unstructured meshing to capture complex geometries quickly
• High-quality near-wall prismatic layers to accurately resolve the boundary layer flow physics

For a CFD engineer, meshing can be an unsung hero or a thorn in your side. At it’s best, the process is simple and easy to use while still delivering accurate results. Lots of tools claim to have “mesh-free” methods, but at the end of the day what really counts is being able to deliver accurate results across the 100’s or 1000’s of cases necessary for aero databases. Today, the current state-of-the-art for this application remains body-fitted finite-volume meshes.

3. Accurate Physics

• A full suite of turbulence models to accurately capture skin friction as well as separated flow dynamics
• A density-based coupled solution of mass, momentum and energy equations

In aerodynamic performance, even a single drag count can equate roughly a million dollars in fuel savings over the lifetime of the aircraft. Further, being able to discern small drag increments between design variations becomes hugely important. As such, accuracy is highly important in these simulations. A good solution would have the ability to capture more subtle effects, such as correctly predicting the location of the shock on the wing as well as larger effects like the side-of-body separation dynamics that have been seen in the Drag Prediction Workshop series. These subtle effects can be captured by using the proper RANS models and sub-models. For more difficult problems, such as predicting the onset of stall, the solution needs to incorporate higher fidelity methods such as DES.

4. Speed and Performance

• Highly scalable solvers for fast turnaround time on any size cluster
• Robust solvers to balance runtime with accuracy & stability

To return to the common thread, aerodynamic performance engineering is all predicated on running large numbers of cases. Any simulation solution needs to be able to turn around these large number of cases, while efficiently using the computer resources available. This means having good parallel scalability for maintaining efficient use of resources as well as being able to quickly reach convergence within a single simfile.

5. Workflow Automation

• The end-to-end workflow in a single environment
• Automate the creation of aero databases without needing any user-driven customization

One of the final keys to a good solution is the ability to put each of the individual steps together. Many different companies offer single solutions to any one of these problems, but the implicit cost of using a limited solution is the need to have internal process development to tie all of the pieces together. When the entire solution is already integrated, there is no worry about formats changing or institutional expertise being tied to a single employee. Having a single end-to-end workflow is critical when developing a full aero database in a regular part of a team’s deliverable.

6. Intelligent Design Exploration

• Intelligent search and design space exploration tightly integrated into CFD Solver
• Explore designs that minimize cruise drag while maintaining constraints on the lift and internal volume

The last piece of the puzzle is going beyond creating aero-databases and looking at exploring the design space. There are many possibilities that could be explored. Looking to reduce drag? Take on a big project like wing design or narrow the focus to the wing-body junction. How can you best incorporate an airframe modification without affecting the performance characteristics or loads margin of safety? What is the best location for the most accurate sensor readings? There are many possibilities out there and the key is a solution that works seamlessly within a design space exploration framework.

Innovation Through Design Exploration

With STAR-CCM+ You Are Able to Automate The Design Exploration and Optimization Process

Why is Aerodynamic Performance Important Today?

TRENDS & IMPLICATIONS in the Aerospace Industry

Stricter Regulations

1. Improve fuel efficiency
2. Reduce noise

Increased Competition

1. Increased pressure to innovate
2. New business models and technologies

New Aircraft Concepts

1. Lightweight materials and structures
2. Reduce expensive field testing
3. Accelerate time-to-market

In the aerospace industry, we see the following main trends:

• Stricter regulation around emissions and fuel efficiency coming out of IATA with a stated goal of carbon-neutral *growth* from 202 and a 50% reduction in CO2-emissions by 2050. Additionally, the ICAO has identified aircraft noise as the most significant cause of negative community feedback to the operation and expansion of airports.
• Increased competition in terms of many new players on the market, specifically in the area of small & regional transport aircraft
• New aircraft and propulsion concepts are very quickly coming to market. These include the continued use and expansion of lightweight materials and structures, development of hybrid-electric propulsion concepts as well as new structural architectures.

How can Performance Engineering Address the Challenges?

Engineering Innovation is Needed to Predict and understand real-world behavior:

1. Air loads across the design envelop
2. Stability and control characteristics
3. Impact of airframe modifications
4. Positioning of sensors

Explore many design variants early in development:

1. Maximize performance
2. Analyze larger portions of the flight envelope
3. Innovate

High fidelity CFD simulations are an integral part of any aircraft program. Additionally, the aerospace industry has always gone beyond a single simulation and been driven by the need to explore large portions of the design envelope. With increasing pressures from regulators as well as pressure to innovate, the need to quickly generate an aerodynamic database is greater than ever before. For the aerodynamics team, these databases are often provided to internal customers, for example, to provide air loads for the linearization of a loads database or to the stability & controls team for the development of flight simulators. As can be seen, aircraft programs are large and inter-connected systems themselves and providing an aero database in a timely manner is critical to keeping the program on time and on budget.

When you look at advances in computer hardware and the ubiquity of cloud computing, even small companies are now able to generate aero databases on a time-scale competitive with, or faster than, physical testing. In fact, CFD is the dominant source of information for relatively “clean” flows like cruise drag. In areas where physical testing remains the main data source, CFD can provide a more in-depth view of the flow field in order to help search out innovative designs. The barriers to running large databases are being removed every day and so why let your simulations solution remain the last barrier?