A Delayed Detached Eddy Simulation Model for the Simulation of Complex Turbulent Flow

Abstract

A new turbulent model based on Delayed Detached Eddy Simulation (DDES) with non-linear eddy viscosity model (NLEVM) was developed to predict the complex turbulent flow. The numerical simulation of the triangular cylinder and the centrifugal pump was carried out to investigate the ability and applicability of the DDES model based on NLEVM (DDES_NL). Compared to the turbulent model based on the eddy viscosity model, the computational results of the triangular cylinder showed the advantage of the non-linear eddy viscosity modification in the DDES_NL model which can improve the accuracy of the prediction in the flow phenomenon with a relatively simple turbulence structure. Regrettably, some small-scale turbulent structures among those still cannot be captured accurately. The numerical simulation of the centrifugal pump predicted by the DDES_NL model shows more abundant flow structures and gets close to the realistic statistical characteristics. It also proves the good applicability of the DDES_NL model in complex flow. This study aims to contribute to the growing area of turbulence modeling by exploring it.

Recent Advances in Airfoil Self-Noise Passive Reduction

“…Scaleresolving techniques maintain a balance between RANS and LES by resolving a certain portion of the turbulent scales in critical domains while modeling the smaller unresolved scales with RANS in other domains. There are different approaches to implementing scale-resolving techniques, including Wall-Resolved LES (WR-LES) [69], Wall-Modelled LES (WM-LES) [70], Scale-Adaptive Simulation (SAS), Zonal Detached ES (ZDES) [71], Detached ES (DES) [72], and Delayed Detached ES (DDES) [73,74]. The percentage of resolved turbulence, and consequently the accuracy and computational cost, decrease with this order [75,76].…”