Cascade-Gust-Interaction Problem Analysis Based on Linear CFD Calculations

A two-dimensional (2-D) cascade-gust-interaction problem, known as the Fourth Computational Aeroacoustics (CAA) Workshop on Benchmark Problems, Category 3, Problem 2, is solved using a frequency domain unstructured Euler solver. The numerical scheme uses a second-order central spatial discretization, and the integration in time is done using a fifth-stage Runge-Kutta scheme. Two-dimensional non-reflective boundary conditions are used at the computational domain inlet and outlet. Unsteady results for three different harmonics are provided, and a mesh sensitivity analysis is carried out to determine the grid resolution required in the solver for this type of calculation.

The code, known as Mu2s2T-L, has been developed at Industria de Turbo Propulsores, SA (ITP), and is used in production to compute turbomachinery unsteady flows due to either vibrating blades or vortical/potential gust interactions between adjacent bladerows. The Mu2s2T-L solver has been extensively validated against several 2-D semi-analytical methods where the fan/turbine blade geometries are replaced by flat plates. In this work, Mu2s2T-L code's ability to deal with complex geometries like a fan blade is tested, and its results are compared with the benchmark solution in a companion paper.