Welcome to the Inside Track with ARC. The Auto Research Center is a specialized research facility serving the motorsport, production, commercial, government and bicycle industries. The ARC global headquarters is located in Indianapolis, Indiana which hosts a 50% scale wind tunnel, 7-post, drivetrain test rig, bicycle test facility and CFD cluster center. ARC offers a wide range of solution packages to further speed and efficiency.
Now available for order at ARC is a more efficient rear wing assembly for the RADICAL SR-3. This rear wing includes a fully shaped 3D wing element and large RWEP with louvers. The design was optimized using CFD Adjoint solver to show the direction and magnitude the wing element needed to be pushed or pulled. Using this data, transient CFD runs were completed and the most efficient shape honed quickly, which was over 5% better than the stock wing and endplates. Adrian Reynard will be using this new wing to aim for his 3rd UK Bikesport Sportcar Championship in a row.
The ARC Aerodynamic Bike Test Facility Wind Tunnel is not the only way to gain a better understanding of cycling aerodynamics. CFD (Computational Fluid Dynamics) is a digital form of aerodynamic analysis and is an excellent tool to help visualize the flow field around the bike and rider.
Most cycling CFD analysis is done using steady state turbulence modeling, which simplifies the flow field calculations using an approximation of the Reynolds Averaged Navier Stokes equations. ARC's ELEMENTS CFD software was coded and validated for transient turbulence. Transient turbulence modelling captures more of the subtle details in the airflow, as demonstrated in the video below. For more advanced analysis the effects of spinning wheels can be modeled using a sliding mesh.
The visualization images from CFD help cycling manufacturers gain a better understanding of how to improve their products, while for bike fitters to help their customers see how air is actually interacting around the body and why proper form is important. If you are interested in a CFD analysis, please contact ARC at 317-291-8600, e-mail biketest@arcindy.com or visit the ARC CFD webpage.
ELEMENTS CFD software, optimized for automotive purposes by Streamline Solutions, the joint venture between ARC and ENGYS Ltd is not just for external aerodynamics. The ELEMENTS CFD interface provides full powertrain cooling analysis, for both heat radiated from the system and internal flow analysis.
The thermal analysis is done in tandem with a 1D code to evaluate and optimize the air side performance of a cooling system, including heat-exchangers, fans and HVAC modules. Exceptional computing scalability (minimal HPC licenses) permits quick iterative cycles. For more on ELEMENTS offerings for thermal analysis testing, visit the ARC website. To get started using CFD, please contact ARC at 317-291-8600 or e-mail sales@arcindy.com.
The partnership between ARC and ENGYS Ltd provides a unique benefit to the ELEMENTS software. ENGYS Ltd is composed of personnel who wrote the core of OpenFOAM coding, while ARC provides the validation tools to ensure top correlation between CFD and actual real world results.
Globally, commercial trucks are vastly different, from long nose tractors in the USA; short nose, tight trailer gap in Europe; to short nose, long trailer gap in Asia. With regulations ever changing and becoming more similar worldwide, we are often asked, "which is better?" The reasons for global differences are larger than just aerodynamics. They include increased safety with long nose tractors, but less weight with short nose tractors, ARC is going to focus on answering the aerodynamic question in the coming months with respect to the trucks.
A previous internal study at ARC showed that putting a long nose on a short tractor design didn't automatically mean a reduction in aerodynamic drag. The entire tractor and trailer package must be considered and optimized. The study will be completed using ELEMENTS CFD software, specially written software for automotive purposes and has been validated using ARC's wind tunnel.
To learn more about ARC's offerings for the Commercial Industry, visit the ARC website, call 317-291-8600 or email at sales@arcindy.com.
Aeroacoustics can indeed be tested at ARC, using ELEMENTS CFD software, through Streamline Solutions, the joint venture between ARC and ENGYS Ltd.
Using the basis of Sir James Lighthill's analogy between the Navier-Stokes equations and noise generation along with Kirchhoff integral, using CFD is a validated way to measure aeroacoustics. Both external and internal analyses are available, including a fully transient DES field flow solution with a pseudospectral method to model sound wave propagation correctly.
To do Aeracoustics testing with ARC, please contact ARC at 317-291-8600 or e-mail sales@arcindy.com
TECH ZONE is an additional area of our newsletter where each month a customer question will be answered by the related expert at ARC. Please send in any questions you might have, from wind tunnel test instrumentation, CFD workings,to tuning your shocks. Ask your questions at techzone@arcindy.com
