INVESTIGATION OF STRENGTH PROPERTIES OF IMPELLERS MADE OF COMPOSITE MATERIAL FOR DIESEL ENGINES

The purpose of the paper is to perform a comparative analysis of the strength properties of impellers made of a composite material with strength properties of impellers made of aluminum alloy. The main method of this study is the finite element method. Pre-and post-processor Femap was used to prepare the model and process the research results. The calculations were performed using a linear solver NX Nastran. Calculations are carried out for two wheel sizes (two diameters) and two calculated cases (for maximum working angular velocity and for destructive velocity). During research stress-deformed states of impellers were obtained. Stress distribution is qualitatively identical in all design options. Redistribution of stresses in impellers due to different materials stiffness is absent. Strength factor as a result of replacement of materials for the 1st and 2nd sizes fell by 7.8 and 5 %, respectively (absolute values - 1.06 and 1.16 respectively). Stress-deformed states obtained during strength calculation can be used for the subsequent manufacture of an impeller made of an anisotropic material. The calculation of frequencies and forms of free oscillations showed a decrease in the frequencies of free vibrations of impellers made of composite material, but it should be noted that even the «lowest» frequencies have approximately twice the maximum frequencies of the working range of the turbocharger. The results of the analysis show the promise of replacing materials in order to improve reliability. Strength calculation showed the need for additional experimental studies of impellers made of composite materials.

centrifugal compressor, turbocompressor, composite material, finite element analysis