Anybody who drives one of Ford’s recent vehicles spends a little less money on gasoline thanks to HPC work the carmaker undertook with Oak Ridge National Laboratory, where more than one million processor hours were spent getting a handle on the complex fluid dynamics governing airflow under the hood.
Carmakers around the world are spending billions of dollars to find ways to comply with new fuel efficiency mandates of the U.S. government. The manufacturers are turning over every rock to find any performance gains, from low rolling resistance tires to hybrid drivetrains.
One area of exploration that may slip by the public’s eye is the flow of air through the front grill of a car into the engine bay, which has a significant impact on the car’s fuel consumption and overall performance. However, understanding how to build for maximum cooling efficiency while simultaneously minimizing front-end drag is a very difficult task because each of the many components within the compartment can alter the airflow.
“Any change in the size and position of just one component can have a significant impact on the computational model as a whole,” said Burkhard Hupertz, the thermal and aerosystems computer-aided engineering (CAE) supervisor at Ford of Europe, in a recent story on the Oak Ridge Leadership Computing Facility website. “Making one more efficient could result in the loss of cooling or increased drag for another.”
In the past, carmakers would spend a large amount of time using the trial and error method to come up with a suitable design. Several years ago, Ford decided to speed the design process and build a prototype model of airflow that could be applied to many cars across its lineup. However, this approach would require running thousands of simulations to find the optimal design parameters. This is what led the team, led by Hupertz and senior HPC technical specialist and lead investigator Alex Akkerman, to ORNL and the Jaguar supercomputer.
The first step in the process was porting its computational fluid dynamics code, called Underhood 3D (UH3D), to Jaguar. After scaling UH3D to run on Jaguar (which has since been transformed into Titan), the Ford team used approximately 1 million processor hours to test 11 geometric and non-geometric parameters (such as cooling fan speed) against four different operating conditions, for a total of 1,600 simulation cases, according to the ORLF story.
The work on Jaguar has enabled Ford to find a design that represents a happy medium between maximizing cooling airflow, while minimizing front-end drag. “Access to Jaguar enabled us to develop a new methodology that allowed Ford, for the first time, to conduct engine bay analysis with the required number of design variables and operating conditions for a true design optimization,” Akkerman told ORLF.
The results are evident in the vehicles that Ford has put on the road the last few years. While Ford has come under fire recently for overstating the mileage of some of its vehicles–specifically the C-MAX Hybrid, for which Ford this month lowered mileage estimates–the carmaker has delivered notable fuel efficiency gains across the breadth of its lineup. At least some of those gains can be attributed to the research done on Jaguar.