Experimental & Computational Simulations Utilized During the Aerodynamic Development of the Dodge Intrepid R/T Race Car 2002-01-3334

Experimental and computational simulation techniques were concurrently employed throughout the aerodynamic development of the NASCAR Dodge Intrepid R/T in order to achieve a greater understanding of the complex flow fields involved. With less than 500 days to design, understand, and build a competitive vehicle, the development team utilized a closed loop approach to testing. Scale wind tunnel models and Computational Fluid Dynamics (CFD) were used to identify program direction and to speed the development cycle versus the traditional process of full scale testing.

This paper will detail the process and application of both the experimental and computational techniques used in the aerodynamic development of the Intrepid R/T race vehicle, primarily focusing on the earlier stages that led to its competition introduction at the start of the 2001 season. Many of the techniques utilized during the development program were in standard use throughout the automotive industry; however, it was the unique simultaneous application of these processes that ensured the most competitive design feasible for the time allowed.

The scale model program will be detailed in this paper, including a discussion of wake imaging technology. A correlation example between CFD, scale model results, and full-scale wind tunnel data for the same R&D vehicle will be shown. Application of CFD to simulate rolling road will be presented, in particular for the aerodynamic configuration mandated by the sanctioning body for super speedways during the 2001 season. Finally, simulation of race conditions through multi-car “drafting” will be shown, with quantification of aerodynamic drag for lead and trail vehicles. This paper will demonstrate that a closed loop validation process can be employed throughout the racecar development cycle to provide greater confidence in complex simulations and in turn lead to greater acceptance of data provided to factory supported race teams.