Numerical Simulation of Small Defects Flow Resistance Characteristics of Thin-walled Components of Titanium Alloy with Adding Material Manufacturing Based on CT Data

Abstract

In order to study the influence of different types of small defects on the flow resistance characteristics of thin-walled components, the method of micro-focus industrial CT images and numerical simulation was used. According to CT imaging technology, there were mainly three types of small defects on the inner surface of the runner: surface pores, surface inclusions, and surface cracks. Extracting small defects, refining the local grid, and establishing the finite element analysis model. Through finite element calculation software Fluent, a low Reynolds number k-e model was adopted to carry out numerical simulation and analysis on the flow channels with three small defects on the inner surface. The results showed that under the same Reynolds number condition, the flow resistance coefficient of surface cracks was the largest, which was much larger than that of surface inclusions and surface pores. The resistance of surface pores and surface inclusions to the flow passage was similar and relatively small. The flow resistance coefficient of three kinds of minor defects decreased with the increase of Reynolds number. In the case of low Reynolds number, the separation of flow boundary layer occurred at the surface cracks.