Numerical simulation of the cavitating noise of contra-rotating propellers based on detached eddy simulation and the Ffowcs Williams–Hawkings acoustics equation

2021 ◽  
Vol 33 (11) ◽  
pp. 115117
Author(s):  
Jian Hu ◽  
Xiaoshen Ning ◽  
Wang Zhao ◽  
Fugeng Li ◽  
Jiachen Ma ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Detached Eddy Simulation ◽  
Eddy Simulation

PIV validation of different turbulence models used for numerical simulation of a centrifugal pump diffuser

2018 ◽  
Vol 35 (1) ◽  
pp. 2-17 ◽  
Author(s):  
Ling Zhou ◽  
Ling Bai ◽  
Wei Li ◽  
Weidong Shi ◽  
Chuan Wang
Keyword(s):  
Numerical Simulation ◽  
Centrifugal Pump ◽  
Turbulence Models ◽  
Detached Eddy Simulation ◽  
Piv Measurements ◽  
Content Type ◽  
Rotating Speed ◽  
Eddy Simulation ◽  
Image Velocimetry ◽  
Velocity Flow

Purpose The purpose of this study is to validate the different turbulence models using in the numerical simulation of centrifugal pump diffuser. Computational fluid dynamics (CFD) has become the main method to study the pump inner flow patterns. It is important to understand the differences and features of the different turbulence models used in turbomachinery. Design/methodology/approach The velocity flow fields in a compact return diffuser under different flow conditions are studied and compared between CFD and particle image velocimetry (PIV) measurements. Three turbulence models are used to solve the steady flow field using high-quality fine structured grids, including shear stress transport (SST) k-w model, detached-eddy simulation (DES) model and SST k-w model with low-Re corrections. Findings SST k-w model with low-Re correction gives better results compared to DES and SST k-w model, and gives a good predication about the vortex core position under strong part-loading conditions. Originality/value A special test rig is designed to carry out the 2D PIV measurements under high rotating speed of 2850 r/min, and the PIV results are used to validate the CFD results.

scholarly journals Hybrid Numerical Simulation of Jet Blast Distance of a Departing Aircraft

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Xin He ◽  
Yaqing Chen ◽  
Yilong Ma ◽  
Dengfeng Hu ◽  
Haoran Gao
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Turbulence Model ◽  
Internal Flow ◽  
Aircraft Engine ◽  
Simulation Method ◽  
Detached Eddy Simulation ◽  
Eddy Simulation ◽  
Numerical Simulation Method

A hybrid numerical simulation method was established by combining the Spalart-Allmaras (SA) turbulence model and detached eddy simulation (DES). Numerical simulations were carried out to model cold and hot spray conditions of a nozzle without considering the internal flow of an engine to determine jet conditions. Analysis results show that the calculated hot spray results more in line with the reality. The jet effect of a typical aircraft engine was simulated numerically to determine the distance influenced by the jet blast from a departing aircraft engine.

scholarly journals Numerical Simulation of Hydraulic Jumps. Part 2: Recent Results and Future Outlook

Water ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 28 ◽  
Author(s):  
Nicolò Viti ◽  
Daniel Valero ◽  
Carlo Gualtieri
Keyword(s):  
Numerical Simulation ◽  
Hydraulic Jump ◽  
Scale Effects ◽  
Cfd Modeling ◽  
Hydraulic Jumps ◽  
Detached Eddy Simulation ◽  
Mean Flow ◽  
Research Activity ◽  
Eddy Simulation ◽  
Rans Modeling

During the past two decades, hydraulic jumps have been investigated using Computational Fluid Dynamics (CFD). The second part of this two-part study is devoted to the state-of-the-art of the numerical simulation of the hydraulic jump. First, the most widely-used CFD approaches, namely the Reynolds-Averaged Navier–Stokes (RANS), the Large Eddy Simulation (LES), the Direct Numerical Simulation (DNS), the hybrid RANS-LES method Detached Eddy Simulation (DES), as well as the Smoothed Particle Hydrodynamics (SPH), are introduced pointing out their main characteristics also in the context of the best practices for CFD modeling of environmental flows. Second, the literature on numerical simulations of the hydraulic jump is presented and discussed. It was observed that the RANS modeling approach is able to provide accurate results for the mean flow variables, while high-fidelity methods, such as LES and DES, can properly reproduce turbulence quantities of the hydraulic jump. Although computationally very expensive, the first DNS on the hydraulic jump led to important findings about the structure of the hydraulic jump and scale effects. Similarly, application of the Lagrangian meshless SPH method provided interesting results, notwithstanding the lower research activity. At the end, despite the promising results still available, it is expected that with the increase in the computational capabilities, the RANS-based numerical studies of the hydraulic jump will approach the prototype scale problems, which are of great relevance for hydraulic engineers, while the application at this scale of the most advanced tools, such as LES and DNS, is still beyond expectations for the foreseeable future. Knowledge of the uncertainty associated with RANS modeling may allow the careful design of new hydraulic structures through the available CFD tools.

scholarly journals Aerodynamic and aeroacoustic behavior of span-wise wavy trailing edge modified SNL 100 m blade

2018 ◽  
Vol 43 (1) ◽  
pp. 4-25 ◽  
Author(s):  
Seung Joon Yang ◽  
James D Baeder
Keyword(s):  
Numerical Simulation ◽  
Parametric Study ◽  
Graphics Processing Unit ◽  
Navier Stokes ◽  
Processing Unit ◽  
Detached Eddy Simulation ◽  
Trailing Edge ◽  
Wind Speeds ◽  
Eddy Simulation ◽  
Edge Modification

The aerodynamic and aeroacoustic behaviors of wavy trailing edge modified flatback wind turbine blade have been investigated through numerical simulation. Previous studies have demonstrated aerodynamic and aeroacoustic benefits of the span-wise wavy trailing edge modification on the flatback trailing edge. The previous two-dimensional airfoil test cases have been extended to a complete set of design parametric study. Aerodynamic and aeroacoustic characteristics of the parametric study have been discussed, relying on the wave size, including recently added cases. Furthermore, in the current study, the wavy trailing edge modification has been applied to the Sandia flatback blade called “SNL100-03FB” and tested in rotating blade conditions. Several variations of the wavy trailing edge design have been tested for a range of wind speeds using an overset computation domain. The numerical simulation employs the in-house developed Navier–Stokes solver, OVERTURNS, as well as Graphics Processing Unit (GPU)-accelerated solver, GPURANS3D. Both are hybrid Reynolds Averaged Navier Stokes (RANS)/Large Eddy Simulation (LES) simulation; delayed detached eddy simulation has been used with the Spalart–Allmaras turbulent model and modified [Formula: see text] laminar–turbulent transition model.

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