| Helicopters operating at low altitude in sandy areas are at increased risk which causing a high mass flux of particle to be injected into the engine inlets. The inlet protection systems are installed in the entrance of engine to ameliorate the situation of engine component damage, the consumption rate of fuel increase and the engine lifetime decrease. In this paper, the influence law of the particle rebound characteristics and the change of the inlet particle separator(IPS) structure are studied by experiment and numerical simulation. The structure of the ejector which eject the sand-carrying air exhausted by IPS is optimized through numerical simulation. The design of the particle rebound test system. The distribution of the rebound speed and the angle of the different size of particle impacting the different material of the walls is obtained from the experimental data based on probability of statistics, the rebound coefficient formula is obtained from the fitting curve. Numerical simulation of IPS is mainly about the numerical calculation of IPS using rebound coefficient fitting formula obtained from the experiment of particle-wall collisions and empirical formula obtained from the documents, and comparing the results of numerical calculation with the test results of IPS, analyzing the difference among them. The result of calculation matches well with the result of the experiment.The design of experimental system of the adjustable three dimensional model of IPS, the influence law of different mainstream flow, different scavenge ratio(SCR), different inlet Mach number, different concentration of sands, different interval of the separator and different profiles of IPS are obtained.The structure of ejector is optimized using Fluent and Workbench software, and the optimization solution is based on the target of ejector coefficient maximum. Finally, three structural parameter values which can maximize the ejector coefficient are determined. |
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