Progressive erosion investigation in elbow pipe: A quantitative assessment using dynamic mesh approach

The study proposes a method for quantifying the progressive erosion in a 90° elbow pipe with dynamic mesh technology, analyzing its impact on erosion and flowing characteristics. The findings reveal that erosion depth and impact count are primarily concentrated in the midsection of the outer elbow, exhibiting elliptical and “V-shaped” distributions, respectively, with the highest values observed for a minimum particle diameter of 0.075 mm. The impact angle demonstrates a contraction-expansion trend, peaking at the contraction zone, while impact velocity is higher on the outer elbow. As particle size increases, erosion depth and impact count decrease, the range of impact angles broadens, and the maximum value shifts inward. Impact velocity declines overall, though localized high values persist. Over time, the depth and number of pits on the elbow wall increase. Maximum erosion depth is higher for small and medium particles, concentrated around 45°, whereas large particles cause maximum erosion near 60°. Material loss from the elbow increases linearly, but the rate of increase gradually diminishes. Large particles cause severe short-term material loss, while small particles contribute more over extended periods. Erosion-induced deformation causes abrupt changes in fluid velocity direction, intensifies vortex strength near the wall, shifts the high-pressure region on the outer elbow toward the deformed area, and expands the erosion region on the inner elbow. Furthermore, impact count is the most critical parameter influencing erosion depth. The findings offer technical support for quantitatively predicting sediment-induced erosion and provides guidance for ensuring reliable pipeline operation.