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This paper is dedicated to the memory of Derlon Chu (Nov. 20, 1959-June 19, 2003)-a colleague and a friend who has contributed much to make CFD impact the design of automotive components. Derlon Chu spearheaded the formation of the "Partnership on CFD Codes and Models for the Automotive Industry" to address error issues in CFD. This paper presents and evaluates a method for estimating grid-induced errors in CFD solutions that recognizes error at one location in the flow domain may not be generated there, but rather generated elsewhere and then transported there. This paper derives a system of discrete error-transport equations (DETEs) to compute the evolution of grid-induced errors in finite-volume solutions of the Euler equations for compressible flows in two dimensions. The finite-volume method to which the DETEs were derived is one which can be applied to structured or unstructured meshes with cells that can be triangular, rectangular, or other polygons. Results for a test problem involving an oblique shock wave show that if the residuals in the DETEs are modeled accurately, then the DETEs can predict grid-induced errors accurately.

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CFD simulation of vehicle under-hood and under-body poses several challenges. Specifically, the complexity of the geometry involved makes the use of traditional mesh generation approaches, based on the boundary-to-interior methodology, impractical and time consuming. The current work presents the use of an interior-to-boundary method wherein the need for creating a ‘water-tight’ surface mesh is not a pre-requisite for volume mesh generation. The application of the new method is demonstrated for an actual passenger vehicle under-hood model with nearly a hundred components. Coupled radiation/convection simulations are performed to obtain the complete airflow and thermal map of the engine compartment. Results are validated with test data. The new method results in significant gains in efficiency over traditional approaches allowing the simulation tool to be used effectively in the vehicle development process.