Xinran Zhao

Abstract: In this paper the heat transfer and residual stress evolution in the direct metal laser sintering process of the additive manufacturing of titanium alloy products are studied. A numerical model is developed in a COMSOL multiphysics environment considering the temperature-dependent material properties of TiAl6V4. The thermo-mechanical coupled simulation is performed. 3-D simulation is used to study single-layer laser sintering. A 2-D model is used to study the multi-layer effects of additive manufacturing. The results reveal the behavior of the melt pool size, temperature history, and change of the residual stresses of a single layer and among the multiple layers of the effects of the change of the local base temperature and laser power etc. The result of the simulation provides a better understanding of the complex thermo-mechanical mechanisms of laser sintering additive manufacturing processes.

TL;DR: In this paper, the authors presented a numerical approach for the analysis of the theoretical flow through spur gear external gear machines, which does not require a-priori knowledge of the gear profile.

TL;DR: A clear interpretation of the displacing action and the transient features of the delivery flow was never addressed in past literature, and an analysis on the kinematic flow ripple is given, showing how such design concept can reduce or even eliminate the k Cinematic flow pulsations.

TL;DR: In this paper, the authors present an approach for the analysis of the ripple source of gear pumps based on decomposition into a kinematic component and a pressurization component.

TL;DR: In this article, an analytical expression for the instantaneous flowrate and flow non-uniformity given by asymmetric, non-standard involute gear pumps is derived and used within a multi-objective numerical optimization algorithm aimed at minimizing both the flow nonuniformities and the pump size to achieve a specific displacement.