This study is to predict the flutter of the first rotor blade of the two-stage axial turbine of a rocket engine turbopump, where the turbine was designed by the Japan Aerospace Exploration Agency (JAXA) in the project of Dynamic Design Team (DDT). The number of blade counts of the first rotor of the turbine is 36. A pre-stressed modal analysis has been carried out using ANSYS Mechanical 18.1 on a single rotor blade using fixed support at the hub and rotational velocity boundary conditions, for getting natural frequencies and mode shapes (eigenvectors). The first four modes of Inconel 718 and Titanium 64 blade have been taken for the CFD calculation. However, ANSYS CFX 18.1 has been taken as the solver for the CFD calculation of the simulations. Reynolds Average Navier Stoke’s equations have been used as the governing equation. H2 ideal gas has been considered as a working fluid. Shear Stress Transport (SST) model has been used as the turbulence model. At the inlet, total pressure and total temperatures are 7.55 MPa and 500 K respectively. At the outlet, static pressure is 1.71 MPa. The blade wall has been considered as a no-slip, whereas the slip wall has been considered for the hub and casing. The rotational speed of the rotor blade has taken as 60600 rpm where the rotational axis is Z-axis. A transient blade row model has been used for the unsteady calculations. Results of this study have been presented by graphical and contour representations. Aerodynamic damping coefficient and blade’s wall work per cycle have been taken as the parameters for the analysis. However, the stability of Inconel and Titanium blades is predicted for -90 ≤ IBPA ≤ +90 degrees, whereas instability or flutter of the blades may occur when -180 ≤ IBPA < -90 degrees or +90 < IBPA ≤ +180 degrees.
- Quote paper
- Khairuzzaman Mamun (Author), 2021, Computational simulation for the prediction of rocket turbine’s blade flutter, Munich, GRIN Verlag, https://www.grin.com/document/1595435