ADREA-HF, which is a Computational Fluid Dynamics (CFD) code, is utilised in order to numerically study the flow and concentration fields within a street-canyon area. The selected site is Runeberg Str., a typical urban street canyon with an aspect ratio of approximately 1:1 in Helsinki, Finland. The ADREA-HF model is a transient, non-hydrostatic, dense transport code, especially developed for d...

Chimera technique has broad applications in complex flow field simulations because of its convenience of the arbitrary boundary interfaces and the easiness of gird generations of subzones. However, the main disadvantage or challenging difficulty lies in the global conservative information exchange between different zones or components. This work aims at assessing the conservation and effects of...

The design of a new, truly robust multigrid framework for the solution of steady-state Reynolds-averaged Navier-Stokes (RANS) equations with two-equation turbulence models is presented. While the mean-flow equations and the turbulence model equations are advanced in time in a loosely-coupled manner, their multigrid cycling is strongly coupled (FC-MG). Thanks to the loosely-coupled approach, the...

Reynolds averaged Navier-Stokes methods often cannot predict shock/turbulence interaction correctly. This may be because RANS models do not account for the unsteady motion of the shock wave that is inherent in these interactions. Sinha et al. [Phys. Fluids, Vol. 15, No. 8 (2003)] propose a shock-unsteadiness correction that significantly improves turbulence prediction across a normal shock in a...

This paper evaluates the solution effects of different Rayleigh-Plesset models (R-P) for simulating the growth/collapse dynamics and thermal behaviour of homogeneous gas bubbles. The flow inputs used for the discrete cavitation bubble calculations are obtained from Reynolds-averaged Navier-Stokes simulations (RANS), performed in high-pressure nozzle holes. Parametric 1-D results are presented f...

The Reynolds-averaged Navier-Stokes (RANS) equations are widely used in turbulence applications. They require accurately modelling the anisotropic Reynolds stress tensor, for which traditional closure models only yield reliable results some flow configurations. In last few years, there has been a surge of work aiming at using data-driven approaches to tackle this problem. majority previous focu...

This paper presents efficient procedures to model multistage flows using Fourier-based methods. The Favre-averaged nonlinear harmonic method is extended compute by introducing rotor–rotor or stator–stator interactions. A unified treatment transfer disturbances through blade–row interfaces also formulated. performance of the proposed demonstrated in a compressor and turbine with different levels...

This paper discusses accuracy improvements to Reynolds-Averaged Navier–Stokes (RANS) modeling of supersonic flow by assessing a wide range factors for physics capture. Numerical simulations reveal complex behavior resulting from shock and expansion waves so, jet emanating rectangular nozzle is considered. PIV based experimental data the available literature used validation purposes. Effect vari...

Aerodynamic performances may be optimised by the appropriate tuning of Active Flow Control (AFC) parameters. For first time, we couple Genetic Algorithms (GA) with an unsteady Reynolds-Averaged Navier-Stokes (RANS) solver using Spalart-Allmaras (SA) turbulence model to maximise lift and aerodynamic efficiency airfoil in stall conditions [1], then validate resulting set optimal Synthetic Jet Act...

Simulations are presented for flow around pairs of circular cylinders at a Reynolds number 3900. The is assumed to be two-dimensional and incompressible in nature the simulations performed using RANS (Reynolds Averaged Navier Stokes) approach with k-ε model. three different configurations cylinders: A tandem configuration where line joining centre parallel mean direction; side-by-side, perpendi...