Boundary layers affected by pressure fields of adjacent compressor blades: A numerical approach

Santiago-Hernández, Jeffrey

Publication

Boundary layers affected by pressure fields of adjacent compressor blades: A numerical approach

Santiago-Hernández, Jeffrey

Abstract

Reynolds Average Navier Stoke (RANS) models and Large Eddy Simulation (LES) model, were used to simulate a two NACA 65-410 airfoil compressor cascade using an overset mesh. For mesh validation, comparison of pressure, lift and drag coefficients with experimental data were performed at different angles of attack (AoA) for a single NREL S-826 airfoil. Results of the NACA 65-410 compressor cascade at an AoA of 0 and 7 deg with turbulent intensities of 1% and 6 % show that LES can capture, with better accuracy than RANS models, the effects produced by the adjacent airfoil in the boundary layer velocities and fluctuations. Also, LES captured flow separation at 74% of the chord (c), confirmed by mean velocity profiles and skin friction coefficient (Cf) calculations. Locations of transition from laminar to turbulent flow were approximated using the Cf. Values were between 41.8% and 43.7% c, in agreement with literature.
Modelos del Promedio de Reynolds para Navier y Stokes (RANS) y el modelo de vórtices grandes (LES) fueron utilizados para simular dos perfiles alares NACA 65-410 en cascada utilizando una maya quimera. Para validar la maya, coeficientes de presión, sustentamiento y arrastre fueron comparados con data experimental para un solo perfil alar NREL S-826 a varios ángulos de ataque (AoA). Los resultados de NACA 65-410 en cascada, con AoA de 0 deg y 7 deg para intensidades turbulentas de 1% y 6%, muestran que LES posee mejor precisión en modelar los efectos producidos por el perfil alar adyacente en las velocidades y sus fluctuaciones dentro de las capas límites. Además, LES es capaz de capturar separación de flujo a 74% de la cuerda. Localización del punto de transición fue estimada utilizando el coeficiente de fricción, valores entre 41.8% y 43.7% de la cuerda fueron obtenidos.