Navier-Stokes 3D Computational Analysis of Incompressible Turbulent Flow in a Curved Rectangular Duct

1996 ◽  
pp. 45-51
Author(s):  
P. Di Martino ◽  
A. Terlizzi ◽  
G. Cinque
Keyword(s):  
Turbulent Flow ◽  
Computational Analysis ◽  
Navier Stokes ◽  
Rectangular Duct

Modified partially averaged Navier–Stokes model for turbulent flow in passages with large curvature

2020 ◽  
Vol 34 (23) ◽  
pp. 2050239
Author(s):  
Weixiang Ye ◽  
Xianwu Luo ◽  
Ying Li
Keyword(s):  
Turbulent Flow ◽  
Turbulent Flows ◽  
Turbulence Model ◽  
Navier Stokes ◽  
Small Scale ◽  
Bounded Region ◽  
Rectangular Duct ◽  
Reynolds Stresses ◽  
Curvature Effects ◽  
Text Model

This study presents a partially averaged Navier–Stokes model, MSST PANS, based on a modified SST [Formula: see text] turbulence model to predict turbulent flows with large streamline curvature. The model was validated for turbulent flow in a [Formula: see text] curved rectangular duct (Re = 224,000) to assess the MSST PANS capabilities. The predictions are compared against flow simulations for the same curved rectangular duct using four turbulence models including the standard [Formula: see text] model, SST [Formula: see text] model, [Formula: see text] PANS model and SST [Formula: see text] PANS model. Comparisons among those numerical results and available experimental data show that the MSST PANS model more accurately predicts the velocity components in all three directions, especially in the wall-bounded region than the other models. The study also shows the advantages of the MSST PANS model for predicting the Reynolds stresses, vorticity, and smaller scale turbulent structures in the wall-bounded region not only qualitatively but quantitatively. Furthermore, the MSST PANS model requires fewer computations than the SST PANS model, indicating that this turbulence model, which takes large streamlines curvature effects into consideration, is an effective alternative for capturing the small-scale turbulence flow structures. This turbulence model is expected to be very useful for engineering applications, especially for flows in turbomachinery.

Characterization of heat transfer and friction loss of water turbulent flow in a narrow rectangular duct under 25–40 kHz ultrasonic waves

Ultrasonics ◽  
2021 ◽  
Vol 114 ◽  
pp. 106366
Author(s):  
Korpong Viriyananon ◽  
Jirachai Mingbunjerdsuk ◽  
Teerapat Thungthong ◽  
Weerachai Chaiworapuek
Keyword(s):  
Heat Transfer ◽  
Turbulent Flow ◽  
Ultrasonic Waves ◽  
Friction Loss ◽  
Rectangular Duct

Parameter Extension Simulation of Turbulent Flows in a Compressor Cascade With a High Reynolds Number

2020 ◽  
Author(s):  
Yan Jin
Keyword(s):  
Reynolds Number ◽  
Turbulent Flow ◽  
Turbulent Flows ◽  
Stokes Equations ◽  
Simulation Method ◽  
Potential Method ◽  
Navier Stokes ◽  
Reference Solution ◽  
Compressor Cascade ◽  
High Reynolds

Abstract The turbulent flow in a compressor cascade is calculated by using a new simulation method, i.e., parameter extension simulation (PES). It is defined as the calculation of a turbulent flow with the help of a reference solution. A special large-eddy simulation (LES) method is developed to calculate the reference solution for PES. Then, the reference solution is extended to approximate the exact solution for the Navier-Stokes equations. The Richardson extrapolation is used to estimate the model error. The compressor cascade is made of NACA0065-009 airfoils. The Reynolds number 3.82 × 105 and the attack angles −2° to 7° are accounted for in the study. The effects of the end-walls, attack angle, and tripping bands on the flow are analyzed. The PES results are compared with the experimental data as well as the LES results using the Smagorinsky, k-equation and WALE subgrid models. The numerical results show that the PES requires a lower mesh resolution than the other LES methods. The details of the flow field including the laminar-turbulence transition can be directly captured from the PES results without introducing any additional model. These characteristics make the PES a potential method for simulating flows in turbomachinery with high Reynolds numbers.

scholarly journals Computational analysis of two-dimensional wing aeroelastic flutter using Navier-Stokes model

2018 ◽  
Vol 9 (4) ◽  
pp. 3459-3472 ◽  
Author(s):  
Magdy Saeed Hussin ◽  
Ashraf Ghorab ◽  
Mohamed A. El-Samanoudy
Keyword(s):  
Computational Analysis ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Aeroelastic Flutter

Computational analysis of turbulent flow through an eccentric annulus under different temperature conditions

2018 ◽  
Vol 28 (9) ◽  
pp. 2189-2207 ◽  
Author(s):  
Erman Ulker ◽  
Sıla Ovgu Korkut ◽  
Mehmet Sorgun
Keyword(s):  
Turbulent Flow ◽  
Stokes Equations ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Content Type ◽  
Non Linear ◽  
Fully Developed Turbulent Flow ◽  
Effects Of Temperature ◽  
Eccentric Annuli ◽  
Pipe Rotation

Purpose The purpose of this paper is to solve Navier–Stokes equations including the effects of temperature and inner pipe rotation for fully developed turbulent flow in eccentric annuli by using finite difference scheme with fixing non-linear terms. Design/methodology/approach A mathematical model is proposed for fully developed turbulent flow including the effects of temperature and inner pipe rotation in eccentric annuli. Obtained equation is solved numerically via central difference approximation. In this process, the non-linear term is frozen. In so doing, the non-linear equation can be considered as a linear one. Findings The convergence analysis is studied before using the method to the proposed momentum equation. It reflects that the method approaches to the exact solution of the equation. The numerical solution of the mathematical model shows that pressure gradient can be predicted with a good accuracy when it is compared with experimental data collected from experiments conducted at Izmir Katip Celebi University Flow Loop. Originality/value The originality of this work is that Navier–Stokes equations including temperature and inner pipe rotation effects for fully developed turbulent flow in eccentric annuli are solved numerically by a finite difference method with frozen non-linear terms.

Investigation of Flow Dynamics Over Transitional-Type Microcavity

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Paulius Vilkinis ◽  
Nerijus Pedišius ◽  
Mantas Valantinavičius
Keyword(s):  
Turbulent Flow ◽  
Flow Regime ◽  
Recirculation Zone ◽  
Transitional Flow ◽  
Navier Stokes ◽  
Flow Topology ◽  
Rans Equations ◽  
Recirculation Flow ◽  
Turbulent Flow Regime ◽  
Transitional Type

Flow over a transitional-type cavity in microchannels is studied using a microparticle image velocimetry system (μPIV) and commercially available computational fluid dynamics (CFD) software in laminar, transitional, and turbulent flow regimes. According to experimental results, in the transitional-type cavity (L/h1 = 10) and under laminar flow in the channel, the recirculation zone behind the backward-facing step stretches linearly with ReDh until the reattachment point reaches the middle of the cavity at xr/L = (0.5 to 0.6). With further increase in ReDh, the forward-facing step lifts the reattaching flow from the bottom of the cavity and stagnant recirculation flow fills the entire space of the cavity. Flow reattachment to the bottom of the cavity is again observed only after transition to the turbulent flow regime in the channel. Reynolds-averaged Navier–Stokes (RANS) equations and large eddy simulation (LES) results revealed changes in vortex topology, with the flow regime changing from laminar to turbulent. During the turbulent flow regime in the recirculation zone, periodically recurring vortex systems are formed. Experimental and computational results have a good qualitative agreement regarding the changes in the flow topology. However, the results of numerical simulations based on RANS equations and the Reynolds-stress-baseline turbulence model (RSM-BSL), show that computed reattachment length values overestimate the experimentally obtained values. The RSM-BSL model underestimates the turbulent kinetic energy intensity, generated by flow separation phenomena, on the stage of transitional flow regime.

Low-Frequency Fluctuations In The Flow Over Confined Cylinder In A Narrow Rectangular Duct At Re = 3 750

2017 ◽  
Vol 12 (1) ◽  
pp. 43-49
Author(s):  
Egor Palkin ◽  
Rustam Mullyadzhanov
Keyword(s):  
Stokes Equations ◽  
Low Frequency ◽  
Horseshoe Vortex ◽  
Navier Stokes ◽  
Infinite Cylinder ◽  
Rectangular Duct ◽  
Mean Flow ◽  
Navier Stokes Equations ◽  
Frequency Modulations ◽  
Bounding Surfaces

Flows between two closely spaced bounding surfaces are frequently appear in engineering applications and natural flows. In current paper the flow over a cylinder in a narrow rectangular duct was investigated by numerical computations of Navier-Stokes equations using Large eddy simulations (LES) at ReD = 3 750 based on cylinder diameter and the bulk velocity at inflow boundary. The influence of the bounding walls was demonstrated by comparing mean flow streamlines with the flow over an infinite cylinder at close Reynolds numbers. A comparison between the time-averaged velocity field in front and past the cylinder with experimental from the literature data showed good agreement although the characteristic horseshoe vortex structures are highly sensitive to Reynolds number and turbulence level at inflow boundary. Most energetic modes in recirculating region were revealed by spectral analysis. These low-frequency modulations were characterized by the pair of dominating vortices which are expected to have high influence on the heat transfer in near wake of the cylinder.

Turbulent Flow Simulations using the Parallelized Multigrid Navier-Stokes Solver

1996 ◽  
pp. 383-386
Author(s):  
Yoonsik Kim ◽  
Soo Hyung Park ◽  
Kum Won Cho ◽  
Jang Hyuk Kwon
Keyword(s):  
Turbulent Flow ◽  
Navier Stokes ◽  
Flow Simulations
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