scholarly journals Heat Transfer Prediction From Large Eddy Simulation of a Rotating Cavity With Radial Inflow

2019 ◽  
Vol 141 (12) ◽  
Author(s):  
Michel Onori ◽  
Dario Amirante ◽  
Nicholas J. Hills ◽  
John W. Chew
Keyword(s):  
Nusselt Number ◽  
Large Eddy Simulation ◽  
Source Region ◽  
Outer Region ◽  
Outer Radius ◽  
Heated Wall ◽  
Navier Stokes ◽  
Eddy Simulation ◽  
Rotating Cavity ◽  
Large Eddy

Abstract This paper describes a large eddy simulation (LES) conducted for a nonadiabatic rotating cavity with a radial inflow introduced from the shroud. The dimensionless mass flowrate of the radial inflow is Cw = 3500 and the rotational Reynolds number, based on the cavity outer radius, is equal to Reθ=1.2×106. The time-averaged local Nusselt number on the heated wall is compared with the experimental data available from the literature, and with those derived from the solution of two unsteady Reynolds-averaged Navier–Stokes (URANS) eddy viscosity models, namely, the Spalart–Allmaras and the k−ω shear stress transport (SST) model. It is shown that the Nusselt number is underpredicted in the lower part of the disk and overpredicted in the outer region by both URANS models, whereas the LES provides a much better agreement with the measurements. The behavior results primarily from a different flow structure in the source region, which, in the LES, is found to be considerably more extended and show localized buoyancy phenomena that the URANS models investigated do not capture.

scholarly journals Heat Transfer Prediction From Large Eddy Simulation of a Rotating Cavity With Radial Inflow

2019 ◽  
Author(s):  
Michel Onori ◽  
Dario Amirante ◽  
Nicholas J. Hills ◽  
John W. Chew
Keyword(s):  
Nusselt Number ◽  
Large Eddy Simulation ◽  
Source Region ◽  
Outer Region ◽  
Outer Radius ◽  
Heated Wall ◽  
Navier Stokes ◽  
Eddy Simulation ◽  
Rotating Cavity ◽  
Large Eddy

Abstract The paper describes a Large Eddy Simulation (LES) conducted for a non adiabatic rotating cavity with a radial inflow introduced from the shroud. The dimensionless mass flow rate of the radial inflow is Cw = 3500 and the rotational Reynolds number, based on the cavity outer radius, is equal to Reθ = 1.2 × 106. The time averaged local Nusselt number on the heated wall is compared with the experimental data available from the literature, and with those derived from the solution of two Unsteady Reynolds Averaged Navier-Stokes (URANS) eddy viscosity models, namely the Spalart-Allmaras and the k-ω SST model. It is shown that the Nusselt number is under-predicted in the lower part of the disc and over-predicted in the outer region by both URANS models, whereas the LES provides a much better agreement with the measurements. The behaviour results primarily from a different flow structure in the source region, which, in the LES, is found to be considerably more extended and show localized buoyancy phenomena that the URANS models investigated do not capture.

Hybrid Large Eddy Simulation/Reynolds-Averaged Navier–Stokes Analysis of a Premixed Ethylene-Fueled Dual-Mode Scramjet Combustor

AIAA Journal ◽  
2021 ◽  
pp. 1-17
Author(s):  
Tanner B. Nielsen ◽  
Jack R. Edwards ◽  
Harsha K. Chelliah ◽  
Damien Lieber ◽  
Clayton Geipel ◽  
...  
Keyword(s):  
Large Eddy Simulation ◽  
Navier Stokes ◽  
Dual Mode ◽  
Eddy Simulation ◽  
Scramjet Combustor ◽  
Large Eddy ◽  
Reynolds Averaged Navier Stokes

Simulation of Vortex Instability in a Pipe Trifurcation

2003 ◽  
Author(s):  
Albert Ruprecht ◽  
Ralf Neubauer ◽  
Thomas Helmrich
Keyword(s):  
Large Eddy Simulation ◽  
Turbulence Model ◽  
Model Test ◽  
Reasonable Agreement ◽  
Navier Stokes ◽  
Extended Version ◽  
Vortex Instability ◽  
Flow Phenomenon ◽  
Eddy Simulation ◽  
Large Eddy

The vortex instability in a spherical pipe trifurcation is investigated by applying a Very Large Eddy Simulation (VLES). For this approach an new adaptive turbulence model based on an extended version of the k-ε model is used. Applying a classical Reynolds-averaged Navier-Stokes-Simulation with the standard k-ε model is not able to forecast the vortex instability. However the prescribed VLES method is capable to predict this flow phenomenon. The obtained results show a reasonable agreement with measurements in a model test.

Large Eddy Simulation of Cross Flow in Pipe Junction

2018 ◽  
Author(s):  
Jiajun Chen ◽  
Yue Sun ◽  
Hang Zhang ◽  
Dakui Feng ◽  
Zhiguo Zhang
Keyword(s):  
Large Eddy Simulation ◽  
Stokes Equations ◽  
Numerical Study ◽  
Three Dimensional ◽  
Cross Flow ◽  
Exciting Force ◽  
Navier Stokes ◽  
Pipe Network ◽  
Eddy Simulation ◽  
Large Eddy

Mixing in pipe junctions can play an important role in exciting force and distribution of flow in pipe network. This paper investigated the cross pipe junction and proposed an improved plan, Y-shaped pipe junction. The numerical study of a three-dimensional pipe junction was performed for calculation and improved understanding of flow feature in pipe. The filtered Navier–Stokes equations were used to perform the large-eddy simulation of the unsteady incompressible flow in pipe. From the analysis of these results, it clearly appears that the vortex strength and velocity non-uniformity of centerline, can be reduced by Y-shaped junction. The Y-shaped junction not only has better flow characteristic, but also reduces head loss and exciting force. The results of the three-dimensional improvement analysis of junction can be used in the design of pipe network for industry.

Large Eddy Simulation of the Flow Around a Diffuser-Equipped Bluff Body in Ground Effect

2011 ◽  
Author(s):  
Lara Schembri Puglisevich ◽  
Gary Page
Keyword(s):  
Large Eddy Simulation ◽  
Bluff Body ◽  
Vortex Formation ◽  
Ground Effect ◽  
Vortical Flow ◽  
Navier Stokes ◽  
Flow Structures ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Flow Features

Unsteady Large Eddy Simulation (LES) is carried out for the flow around a bluff body equipped with an underbody rear diffuser in close proximity to the ground, representing an automotive diffuser. The goal is to demonstrate the ability of LES to model underbody vortical flow features at experimental Reynolds numbers (1.01 × 106 based on model height and incoming velocity). The scope of the time-dependent simulations is not to improve on Reynolds-Averaged Navier Stokes (RANS), but to give further insight into vortex formation and progression, allowing better understanding of the flow, hence allowing more control. Vortical flow structures in the diffuser region, along the sides and top surface of the bluff body are successfully modelled. Differences between instantaneous and time-averaged flow structures are presented and explained. Comparisons to pressure measurements from wind tunnel experiments on an identical bluff body model shows a good level of agreement.

Sign in / Sign up

Export Citation Format

Share Document