The Effect of Composite Material on Rotor Dynamics

General Electric Aviation focused on the development and application of advanced, lightweight and durable composite materials and specialized coatings in jet engines, and produced the GEnx (General Electric Nextgeneration), a twin-rotor, axial-flow, high-bypass turbofan jet engine. Derived from the GE90 family, this engine was introduced in 2007 for the Boeing 747-8 and 787 Dreamliner to replace the CF6 in its product lines. Carrying composite technology from the GE90 family, the GEnx used 18 composite fan blades, a composite fan case and titanium aluminide stage 6 and 7 low-pressure turbine blades. Weight reduction through the use of lightweight composite materials resulted in a 15% improvement in specific fuel consumption compared to the CF6. The GEnx can achieve a high BPR of 9.0:1 and a massive OPR of 58.1:1 thanks to its 10-stage HP compressor supported by larger, more efficient fan blades. In this article, an example application is presented examining the effect of a composite material on the rotor with the application of Industry 4.0, a new field.

1. Introduction

In the 3D geometric model created using Ansys-Fluent, the figure shows the boundaries of air flowing around the cylindrical fan. [caption id="attachment_131250" align="aligncenter"] Figure 1. Mesh image of a composite cast (potential) rotor solution.[/caption] [caption id="attachment_131251" align="aligncenter"] Figure 2. Mesh image for determining the torque of the rotor in the center of the composite cast horizontal fan (metal cast).[/caption] [caption id="attachment_131252" align="aligncenter"] Figure 3. "Zoom" mesh image of rotor and fan block.[/caption] After the viscous model to be applied is set as k-ε (realizable) and "scalable wall", the density value for air flowing from the red and blue regions of Figure 3 is entered as 1.2 kg/m³. The rotor speed is a small value of 300 rpm. Air inlet (blue region) velocity is 1.2 m/s.

2. Results

The results obtained at 2100 iterations are given below. [caption id="attachment_131253" align="aligncenter"] Figure 4. Velocity distribution shown on the symmetry axis.[/caption] As seen in Figure 4, the velocity distribution is directly dependent on the rotor rotation speed in blade design. The reduction in rotor weight depending on the rotation speed increases the energy requirement needed for the rotation torque. At 300 rpm rotor speed, the use of lightweight composites significantly affects the energy requirement in rotor rotation. For more detailed solutions of our article, you can contact me from our contact information. I wish you all healthy and happy days.

Dr. Cemil Koyunoğlu Yalova University Faculty of Engineering Department of Energy Systems Engineering