Session: 05-07-02: CFD Development and V&V

Paper Number: 131145

131145 - A Comprehensive Study for Defining the Uncertainty of Erosion Simulations 

Uncertainties are part of any scientific measurements and calculations. As a complex phenomenon, erosion is affected by many independent parameters and consequently, the uncertainties of these parameters contribute to uncertainties in erosion measurements or simulations/predictions. Erosion experiments are costly and time-consuming, hence other means must be used to obtain erosion values. Prediction tools are extremely beneficial for estimating solid particle erosion as conducting erosion measurements can be costly, time-consuming, and in many situations impossible due to extreme conditions. Among the most reliable and accepted methods of erosion predictions is computational fluid dynamics (CFD), which is used by many industries to obtain erosion estimations. So, the uncertainty of numerical results for calculating erosion is important for the integrity of industrial systems dealing with the transport of particles. One of the most utilized frameworks for uncertainty estimation of simulations is the ASME Standard of Validation and Verification (ASME V&V). According to this standard, there are three main elements of uncertainties in any simulation; input, numerical, and modeling. The input uncertainties are the result of the uncertainties in the input parameters for the case of erosion simulations there are parameters such as flow velocity, particle size distribution, and fluid density variations. The numerical element is due to the generated grid and spatial discretizations. For the sake of adapting the process to the erosion simulation, a new element was added as simulation uncertainty. The simulation element includes the effect of parameters such as rebound models, turbulence models, and wall functions. The modeling element is estimated by an implicit method developed by ASME. This element is heavily influenced by the results of measurements, i.e. the measured data and their corresponding uncertainties. In this research, ASME’s guideline is utilized for estimating erosion uncertainty for cases with and without measurement data available. For cases with measurement data available ASME procedure was used for estimating the uncertainties. Two alternatives are introduced to be used as replacements for cases where data is not available. These alternatives are machine learning predictions and erosion correlations both developed based on a significant number of experiments. The database used in this study includes experimental data with air-sand flows in 3 and 4-inch elbows conducted with 75, 150, and 300-μm sand particles. Finally, the estimated bounds of uncertainties are compared with the bounds obtained based on measurements. These comparisons show good agreement between the estimated and measured bounds of uncertainties. The results showed good agreement among calculated and measured bounds of uncertainties.

Presenting Author: Elham Fallah Shojaie University of Tulsa