Closure modeling in bridging regions of variable-resolution (VR) turbulence computations

Abstract

Abstract Optimal utilization of computational resources mandates spatio-temporal variation in resolution for computing complex engineering flows. Closure modeling in regions bridging between different resolutions is rendered difficult due to changing interactions between resolved and unresolved fields. We develop a closure model for the bridging region based on energy conservation principles. Then we proceed to provide a proof of concept in decaying isotropic turbulence with temporally varying resolution. The simplicity of the flow permits a thorough examination of various aspects of the proposed closure not feasible in more complex flows. The results demonstrate the potential promise of the approach, but more validation studies need to be performed.While the present development is in the context of partially averaged Navier–Stokes (PANS) method, the closure principle should apply for other variable-resolution (VR) approaches. Keywords: turbulenceturbulence modelingvariable resolutiondecaying isotropic turbulence Acknowledgements This project was partly funded by FOI (Stefan Wallin) and NASA NRA NNX07AB25A (Sharath S. Girimaji).