Predictive-Computational Fluid Dynamics Validation Assessment for an Impinging Diffuser Flow

As part of a Predictive-Computational Fluid Dynamics (P-CFD) verification and validation (V&V) program, post-processed CFD analysis results are being compared to high-quality, high-resolution validation-level flow field data obtained from fundamental experiments. This paper provides initial results and findings from the CFD validation assessment of an impinging diffuser flow (IDF) using validation-level flow field data obtained from experiments. The paper describes the CFD models, meshing, solutions, and error assessments for comparison to experimental results from the experimental data. To date, quantitative comparisons have been performed for velocity profiles and turbulent statistics taken from laser Doppler and particle image velocimetry measurements as well as surface static pressure measurements. Methods for quantifying the computational uncertainty through the Grid Convergence Index (GCI) and experimental uncertainties including both instrumentation as well as flow condition uncertainty are discussed. This paper also identifies tasks and issues that will improve modeling and experimental methods for future Predictive CFD V&V assessments.