DESIGN AND MULTI-PERSPECTIVE INVESTIGATIONS ON THE AERODYNAMIC PERFORMANCE FACTORS OF CONVENTIONAL AND ADVANCED UAV’S MICRO GAS-TURBINE ENGINE NOZZLES THROUGH VALIDATED CFD APPROACH

Abstract

This paper describes the internal flow behaviors, aerodynamic performance effects, noise reduction techniques, and structural characteristic study on micro gas-turbine engine (MGTE) nozzles for small fixed-wing unmanned aerial vehicles (UAV). Firstly, the primary purpose is to obtain the aerodynamic performance, aeroacoustic, and structural parameters of the nozzle when applied to the MGTE. A baseline MGTE convergent nozzle is investigated on aeroacoustics and structural characteristics. Secondly, the baseline design is implemented with noise reducers, which include notches, a step-back airfoil, and nature-inspired notches. The notch initiates small disturbances on the surface of the jet plume and deforms the shear behind the nozzle, which in turn causes suppression in the jet mixing noise. Thirdly, the step-back airfoil is used in the nozzle's trailing end to optimize the flow at the exit. This causes turbulence and flow separation at the steps located at 50% of the chord length. Here, the step-back airfoil is done with a NACA0018-based configuration. Fourthly, nature-inspired notches impose computational performances on the aerodynamic factors, so the variations are noted. The notch, airfoil, and nature-inspired notch counts are increased and decreased to find the optimum model with minimal acoustic levels. The nozzle is modeled using CATIA and analyzed in the Ansys workbench. Furthermore, the model is tested through an advanced experiment facility and analyzed for pressure variations, velocity variations, and thermal variations by implementing numerous materials.