Erosion Testing and Modeling of a Triangular Elbow As Compared to a Circular Elbow

The erosion patterns in elbows with circular cross-sections have been investigated extensively experimentally and computationally in the past. However, in a bid to reduce erosion in elbows, a new triangular (in cross-section) elbow has been designed and investigated comprehensively during this study. The goal of this work was to examine experimentally and predict computationally using existing erosion models, the erosion patterns in a triangular elbow geometry and compare it to circular elbows for stainless steel materials. Initially, computational fluid dynamics erosion modeling was used to compare erosion in a triangular in-cross-section elbow to a circular elbow. Computational fluid dynamics were then followed by an experimental investigation using flow visualization with a paint removal study to determine the location where particles impinge and lead to erosion. Erosion measurement experiments are also conducted in a flow loop containing liquid and 300 microns sand particles. Within the experimental rig, to avoid abrupt changes of the triangular elbow with the circular pipe, a smooth transition region is designed and utilized. Various transition geometries such as transition length, eccentricity have been investigated with CFD to ensure smooth flow and reduced erosion from the circular pipe to the triangular elbow. CFD simulation results showed that erosion also occurred on the side of the triangular elbow and have been concurred by the paint study as well. It is observed that the erosion in the triangular elbow is approximately 68% lower than that in the circular elbow for the tested conditions. Thus, it is advantageous to use these elbows for practical applications such as fracturing to reduce replacement time of elbows.