Numerical investigation on flow field characteristics of integral particle separator
This paper is a study and research result of vane less integral particle separator where numerical simulation of its inner flow field and the particle movement locus characteristic was undertaken with the application of calculation software Fluent. This paper obtains the characteristic of the total pressure loss from the inlet to the clearance stream outlet and the main stream outlet while the SCR differs, and its inner flow field, and also the distribution of total pressure loss at the clearance stream outlet and particle movement locus. The calculation was undertaken by using the Realizable k-ε model and using Lagrange track model for discrete phase. The research result shows: In the clearance stream, the fluid appears of the whirlpool structure. The total pressure loss decreases while the SCR increases, and increases as the main stream flow increases. On the inner side at the clearance stream outlet (near the splitter), the total pressure loss decreases as the SCR increases, while in the outer side (near the outer wall), the total pressure loss increases as the SCR increases. In the main stream, the total pressure loss increases as the SCR and the main stream flow increase. Micro-size particles barely collide with wall, and some of them enter the main stream flow, while most of large grain size particles collide with wall and enter the clearance stream where they are discharged.
Viscous flow analysis for advanced inlet particle separators
A fully viscous particulated flow analysis for inertial particle separators is presented. It comprises of three main elements: 1) A full Navier-Stokes solver on generalized curvilinear coordinates to map the viscous compressible flow in the IPS, 2) A grid system which is ideally suitable for the IPS split flow, and 3) A particle trajectory analysis that accounts for the effect of gas on the particle motion. This procedure was verified by comparing the predicted results with experimental data obtained from a 5 lb/sec inlet particle separator. Good agreement between the test data and analytical predictions indicates that such a procedure is important in the development process of future high performance inlet particle separators.
Particle Dynamics of Inlet Flowfields with Swirling Vanes
The particle trajectories are investigated for the inlet flowfield of a helicopter engine with swirling vanes and particle separator. The flowfield resulting from the swirling vanes is first computed on a hub-shroud midchannel stream surface. The trajectories of the solid particles are then determined in this flowfield, including particle impacts with the hub, tip, and vane surfaces. The particle rebounding velocity and direction after each impact is determined using empirical correlations derived from experiments conducted in a special tunnel. Different particle sizes are considered, and the resulting trajectories and separator effectiveness are presented.