Abstract
The Aeroengine compressor blades design and weight play vital role in overall performance of the gas turbine engine efficiency. Often a particular blade profile will give more engine performance efficiency but may not have enough strength to withstand the vibration loads. Further if the natural frequencies of the blade coincide with high excitation frequency regions, then it will lead to high cycle fatigue (HCF) failures. In this scenario, it is required to increase the stiffness and weight of the blade by compromising on the aerodynamic performance.
In this paper, it is proposed to use the spatially distributed ceramic particle reinforced composites in local areas of the aeroengine compressor blades without changing the blade outer geometry to move the critical and fundamental frequencies away from the high excitation/vibration loads frequency regions. The typical aeroengine compressor blade geometry with titanium material (Ti-6AL-4V) and Silicon Carbide (SiC) particles as reinforcement have been considered for this case study. The multi-scaling modelling approach has been used using micro-macro scale modelling of randomly distributed particle reinforced composites. The effective material properties like stiffness and density of the composite have been calculated using a micro-scale Unit Cell approach for different volume fractions of the SiC particles. The effective material properties obtained from the micro-scale modelling have been used at local regions of the compressor blade (macro-scale) to simulate the effect of SiC particle reinforcement on the overall macro-scale compressor blade behavior. The natural frequencies of the baseline Titanium blade have been compared with the SiC reinforced composites with different volume fractions. The vibratory stresses and the tip displacements have been compared between the baseline blade and the ceramic particle reinforced blade at different critical frequencies. Using this approach, it is possible to tune the frequencies of the Aeroengine compressor blades design to achieve the improved performance and reduced vibratory stresses which will helps to improve the overall efficiency of the aeroengines with reduced Specific Fuel Consumption (SFC).
