Additive Manufacturing of Hydraulic Components - Pressure Loss Comparison of Different Self-Supporting Channel Geometries

Abstract

Additive manufacturing (AM) and in particular laser powder bed fusion (LPBF) are increasingly being used as manufacturing technology in hydraulics for flow optimization, function integration and weight reduction. These advantages can especially be exploited in hydraulic manifolds. Conventional manifold intersections are created by crossing two vertical bores. The turbulence resulting from the sharp edges and the deflection leads to undesired flow losses. These can be avoided with the design freedom of LPBF, which allows flow optimization in hydraulic channels. However, the development of new channel geometries is limited by design guidelines. Starting from a straight, round channel geometry, this paper presents the steps to design self-supporting channel geometries for horizontal build up. Therefore, different cross-sectional shapes are tested, and critical design details are explained. In addition, this paper examines the influence of post-processing methods on AM components. A comparison of the different geometries is shown with a CFD simulation as well as FEM simulation for strength investigation. For experimental investigation and simulation validation, selected test specimens were printed and post-processed. With a new designed test rig, the pressure losses of the different geometries and post-processing methods were measured and a comparison with the simulative results is shown. Overall, this paper provides an overview of the necessary steps in the design of hydraulic AM components for flow optimization.