Millennium M1: For the Ultimate Balance of Vehicle Aerodynamics and Aesthetics!

5 Mar 2024 • 5 minute read

Advances in the aerodynamic performance of commercial vehicles owe much to the racing industry, which has pioneered many groundbreaking technologies. These technologies have significantly contributed to commercial vehicle performance, from disc brakes to turbocharging. However, their cost can be prohibitive, so it is essential to balance innovation with affordability when considering new aerodynamic changes. Along these lines, computational fluid dynamics (CFD) is a valuable tool for assessing the aerodynamic implications of such modifications. It can analyze and simulate fluid flow, heat transfer, and related phenomena.

Engineers can use CFD software to evaluate the impact of changes in design, materials, and operating conditions on the aerodynamic performance of automobiles. This data can then be utilized to optimize designs, improving safety, efficiency, and performance. In this blog post, we will explore two complementary aspects of automotive design—aerodynamic performance and aesthetics in commercial vehicles. We'll also learn how CFD can aid in achieving the perfect balance between these two aspects.

Aerodynamic Parts that Improve Downforce in Race Cars

Designing a race car is a blend of both science and art. Speed, stability, and agility are the three important aspects to consider in a race car design. Aerodynamics plays a significant part in deciding the performance of a vehicle. A few aerodynamic parts in racing cars are designed to generate downforce, which is the force that pushes the car down onto the track, increasing its grip and stability. From splitters to rear wings, diffusers to side skirts, and NACA ducts, each component is carefully crafted to generate downforce.

At the front of the car, the splitter creates a low-pressure zone under the car, which sucks it down and enhances its handling. Meanwhile, the rear wing creates a high-pressure zone above the car and a low-pressure zone below it, generating downforce that can be fine-tuned to improve performance. To ensure good control of the car, it is essential to have the right balance between front and rear downforce.

But the aerodynamic design doesn't stop there! Diffusers at the rear of the car help manage airflow and reduce drag, while side skirts reduce the amount of air flowing under the car, further improving its efficiency. And let's not forget about the NACA ducts that channel air to the engine bay or brakes, increasing airflow.

When designing a race car, maximizing downforce alone increases drag and leaves the vehicle susceptible to porpoising. Control surfaces that generate downforce create drag, reducing the car's acceleration and top speed. Formula 1 designers create variable control surfaces to overcome this challenge to balance the tradeoff between downforce and drag. This is an example of designing against competing variables in car design.

Why Balancing Aesthetics and Functionality in Commercial Vehicles Is Essential

When it comes to the external aesthetics of a vehicle, it is essential to consider the impact of various modifications on aerodynamics. While aerodynamic enhancements are critical to improving the performance and efficiency of commercial vehicles, certain external features can create significant drag, leading to increased wind resistance and reduced vehicle speed. This drag can cause the engine to work harder, decreasing fuel efficiency and potentially higher maintenance costs.

External features such as bulky roof racks, oversized side mirrors, and protruding antennas can increase the vehicle's frontal area, significantly impacting drag. Similarly, customized body kits, spoilers, and other aftermarket accessories can disrupt the smooth flow of air over the vehicle's body, leading to turbulence and increased drag. In some cases, these modifications can even create a "lift" effect, which can cause the vehicle to become unstable and difficult to control at high speeds.

Car manufacturers invest much time and resources into testing and analyzing a vehicle's aerodynamic performance to ensure optimal design. As a result, making unnecessary modifications that could negatively impact the vehicle's aerodynamics is generally not recommended. However, with careful consideration and balancing of style and functionality, drivers can choose modifications that enhance the vehicle's performance without compromising aerodynamic efficiency.

Transforming Automotive Design with the Millennium M1 CFD Supercomputer

CFD simulations have become increasingly popular for shortening lengthy design cycles and minimizing the number of expensive experiments. However, traditional CFD solver technology's accuracy and speed limitations and computing resource constraints have restricted the potential for CFD analysis. These challenges have typically hindered efficient virtual engineering for CFD users.

Designing a visually appealing and highly efficient vehicle requires a series of simulation tests that can be costly and resource-intensive. In addition, obtaining accurate solutions from these simulations is crucial to minimize the need for prototyping. The Cadence Millennium M1 CFD Supercomputer is an innovative turnkey CFD solution that addresses these challenges through a combination of cutting-edge graphic processing units (GPUs) and CFD solvers, such as the Cadence Fidelity LES Solver for large eddy simulations (LES), along with scalable high-performance computing (HPC) hardware. This powerful solution unlocks unparalleled performance, allowing optimized vehicle design with reduced drag and improved aerodynamics while maintaining its aesthetic appeal.

For a given investment in computing, the Fidelity LES solver provides an up to 10X increase in throughput relative to CPU. For a fixed simulation throughput, the reduction in energy requirement of GPU computing versus CPU computing is about 17X. To further illustrate, the drag and wake prediction of the TUM DrivAer automobile using a grid size of approximately 144 million cells had a turnaround time of only 4.6 hours using two Millennium nodes with the Millennium M1.

Commercial vehicles are constantly being redesigned to improve their aerodynamics and fuel efficiency. One promising area of innovation is the use of technologies from racing cars. However, incorporating these designs into commercial vehicles requires multiple simulation runs to balance aerodynamic effectiveness and aesthetics while aligning to fuel efficiency standards and commercial vehicle regulations. This is where the Millennium M1 CFD Supercomputer comes in handy. With its powerful GPUs and LES solver, it is an unparalleled solution for CFD simulation. This allows multiple design tests to be conducted in a few hours, radically reducing the design simulation time and eliminating the need for physical testing.

Check out the blog posts and articles below to learn more about Cadence's Millennium platform and CFD solutions: