Large Eddy Simulation (LES) is an effective intermediate approach between DNS and RANS, capable of simulating flow features which cannot be handled with RANS such as significant flow unsteadiness and strong vortex-acoustic couplings, and providing higher accuracy than RANS at reasonable cost but still typically an order of magnitude more expensive. Desirable modeling choices involve selecting a...

The paper evaluates a new method to prescribe synthesized turbulent inlet boundary conditions. The method can also be used when prescribing turbulent fluctuations at an interface between (U)RANS and LES regions when the flow enters the LES region. When making LES, DES or hybrid LES-RANS a precursor channel DNS is often used. The disadvantage of this method is that it is difficult to re-scale th...

This paper is addressing of a coupling Large-eddy simulation (LES) and RANS turbulence models with mixture fraction/probability density function as combustion model. The two have been implemented to simulate ethanol-air spray combustion. gas phase described the Eulerian approach while liquid designed using Lagrangian framework. LES/PDF obtained statistically. sub-grid scale energy equation used...

Deep learning (DL)-based Reynolds stress with its capability to leverage values of large data can be used to close Reynolds-averaged Navier-Stoke (RANS) equations. Type I and Type II machine learning (ML) frameworks are studied to investigate data and flow feature requirements while training DL-based Reynolds stress. The paper presents a method, flow features coverage mapping (FFCM), to quantif...

Numerical shape optimization for aerodynamic problems can lead to improved designs than what is possible by conventional methods. Gradient-based optimization methods require the development of adjoint codes which can be a lengthy exercise and is also not very mature for RANS-based approaches. Furthermore, they may lead to locally optimal solution only, which is not desirable, especially in a pr...

T h e covariance ma t r i x of a rotationally s y m m t r i c shape i s a scalar ident i ty ma t r i x . In this paper, w e apply this property of covariance m a t r i x t o deskew the skewed shape of rotational s y m m e t r y . T h e parameters of the deskew t rans format ion m a t r i x are solved by lett ing the covariance ma t r i x of t he t rans formed shape be equal t o a scalar ident i...

In this work, we present a hybrid solver coupling a high-order LES solver with Cartesian mesh and a RANS solver with body-fitting mesh. This hybrid solver is developed within a dual-mesh consistent hybrid framework, where LES and RANS simulations for the same flow are conducted simultaneously on different computational domains and different meshes. In the LES, an immersed boundary method with r...

The synthetic turbulence generator (STG) lies at the interface of Reynolds averaged Navier–Stokes (RANS) simulation and large-eddy (LES). This paper presents an STG for multiple-relaxation-time lattice Boltzmann method (LBM) framework high friction numbers, with consideration near-wall modeling. Reichardt wall law, in combination a force-based method, is used to model field. wall-modeled LES re...