Many different approaches to solving Fluid Mechanics problems are used at Pratt & Whitney Rocketdyne. A common thread is the examination of the problem followed by an analytical process staged into tiers, or levels of analysis (LOA). Geared to the complexity of fluid flows, this approach starts small and builds understanding. This understanding is used to best implement higher levels of analysis, such as Computational Fluid Dynamics, and experiment. Our staff is experienced at all levels of analysis, and that experience is complimented by this process to ensure the fastest, most cost-effective solutions.