Performance Assessment of Reynolds Stress and Eddy Viscosity Models on a Transitional DCA Compressor Blade

Abstract

In the current work a detailed investigation and a performance assessment of two eddy viscosity and two Reynolds stress turbulence models for modelling the transitional flow on a double circular arc (DCA) compressor blade is presented. The investigation is focused on the comparison of the obtained computational results with available experimental data for a specific DCA compressor blade cascade which can be found in the European Research Community on Flow, Turbulence and Combustion (ERCOFTAC) experimental database. The examined flow field is very challenging for the performance assessment of the turbulence models. The blade inlet angle departs +5° from the compressor blade design conditions resulting in a complex flow field having large regions of boundary layer transition both on the suction and pressure sides of the blade with the presence of an unsteady wake. The presented results include velocity and turbulence intensity distributions along the pressure, the suction sides, and the wake region of the blade. From the comparison with the available experimental data, it is evident that in order to accurately compute such complex velocity and turbulence fields that are met in aero engine components (compressors and turbines), it is obligatory to use more advanced turbulence models with the Unsteady Reynolds Averaged Navier Stokes Equations (URANS) adoption, or other simulation and hybrid methodologies which require unsteady calculations.

Analysis of turbulent wall jet impingement onto a moving heated body

“…The RSM turbulence model is used. Governing equation of RSM equations can be written as (Vlahostergios, 2018; ANSYS Fluent Theory Guide, 2020): where D Tij , D L,ij , P ij , G ij , φ ij and ε ij represent turbulent diffusion, viscous diffusion, stress production, buoyancy production, pressure strain and dissipation rate, respectively.…”

“…In general, the φ ij pressure strain correlation term reflects the energy redistribution among the Reynolds stresses, the interaction of the mean velocity gradient field and the fluctuating velocity field in RSM models. It is also in charge of describing the Reynolds stresses return to isotropy as a result of energy redistribution (Vlahostergios, 2018). Here, k is the turbulence kinetic energy modeled as: …”

“…The RSM turbulence model is used. Governing equation of RSM equations can be written as (Vlahostergios, 2018; ANSYS Fluent Theory Guide, 2020):…”

“…Also, the surface roughness has a positive effect on the heat transfer when the jet dimensions are compared with the Reynolds number. Vlahostergios (2018) studied the turbulence caused by high fluid velocity on the compressor blade in a numerical study. Taking the blade angle at 5° and the fluid inlet velocity at 33 m/s.…”

Accuracy of the Gamma Re-Theta Transition Model for Simulating the DU-91-W2-250 Airfoil at High Reynolds Numbers

“…A general-purpose transition turbulence model should enable the user to calibrate, it should consider different transition mechanisms, and above all, it should be formulated locally. A unique correlation-based transition turbulence model, also known as the γ − Re θ model, is based strictly on local variables [35,41,42]. The purpose of the inventors was to develop a general-purpose turbulence model that would be compatible with modern CFD codes that can use unstructured meshes.…”