DNS 1-2 Description: Difference between revisions
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= Review of previous studies = | = Review of previous studies = | ||
Provide a brief review of related past studies, either experimental or computational. Identify | Turbulent channel has been one of the canonical test cases to study the characteristics of wall bounded turbulence. | ||
The simplified setup proposed by Kim et al. (1987)<ref>Kim,J., Moin, P. and Moser, R., Turbulence statistics in fully developed channel flow at low Reynolds number, J. Fluid Mech. 177, 133-166, 1987</ref> is now a standard test case for wall bounded turbulent flow simulations. | |||
The setup is computationally inexpensive as it a periodic channel flow with periodic boundary conditions in the spanwise and streamwise directions. | |||
With recent progress made in computing infrastructure, Reynolds numbers as large as <math>Re_\tau=4000</math> (Bernardini et al. 2014) and <math>Re_\tau=6000</math> (Pirrozoli et al. 2021) are now available. Nevertheless, the <math>Re_\tau=180</math> case by Kim et al. still remains | |||
as a benchmark case for wall bounded turbulent flow simulations. | |||
<!--Provide a brief review of related past studies, either experimental or computational. Identify | |||
the configuration chosen for the present study and position it with respect to previous studies. | the configuration chosen for the present study and position it with respect to previous studies. | ||
If the test case is geared on a certain experiment, explain what simplifications ( e.g. concern- | If the test case is geared on a certain experiment, explain what simplifications ( e.g. concern- | ||
ing geometry, boundary conditions) have been introduced with respect to the experiment in the | ing geometry, boundary conditions) have been introduced with respect to the experiment in the | ||
computational setup to make the computations feasible and avoid uncertainty or ambiguity. | computational setup to make the computations feasible and avoid uncertainty or ambiguity.--> | ||
= Description of the test case = | = Description of the test case = | ||
An idealised channel flow, without side walls, is considered. The details of the case are given in [https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/identifying-eigenmodes-of-averaged-smallamplitude-perturbations-to-turbulent-channel-flow/EF03E2FFFF1A481FC55448B3F11496F2 Iyer et al.(2019)]<ref name="iyer2019">'''A. Iyer, F. D. Witherden, S. I. Chernyshenko and P. E. Vincent''', Identifying eigenmodes of averaged small-amplitude perturbations to turbulent channel flow, Journal of Fluid Mechanics, 875 (758-780), 2019</ref>. The current set of simulations has a higher grid resolution in the wall normal direction. | An idealised channel flow, without side walls, is considered. The details of the case are given in [https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/identifying-eigenmodes-of-averaged-smallamplitude-perturbations-to-turbulent-channel-flow/EF03E2FFFF1A481FC55448B3F11496F2 Iyer et al.(2019)]<ref name="iyer2019">'''A. Iyer, F. D. Witherden, S. I. Chernyshenko and P. E. Vincent''', Identifying eigenmodes of averaged small-amplitude perturbations to turbulent channel flow, Journal of Fluid Mechanics, 875 (758-780), 2019</ref>. The current set of simulations has a higher grid resolution in the wall normal direction. | ||
Revision as of 09:53, 12 October 2021
Introduction
The turbulent Channel Flow is one of the canonical flows used to study turbulence in wall bounded turbulence. DNS of turbulent channel flow were undertaken at . DNS were undertaken using PyFR (http://www.pyfr.org/) version 1.12.0:
- based on the high-order flux reconstruction method of Huynh
- compressible solver
- a Rusanov Riemann solver was employed to calculate the inter-element fluxes
- an explicit RK45[2R+] scheme was used to advance the solution in time
- Fifth order polynomials are used for the computations
Review of previous studies
Turbulent channel has been one of the canonical test cases to study the characteristics of wall bounded turbulence. The simplified setup proposed by Kim et al. (1987)[1] is now a standard test case for wall bounded turbulent flow simulations. The setup is computationally inexpensive as it a periodic channel flow with periodic boundary conditions in the spanwise and streamwise directions. With recent progress made in computing infrastructure, Reynolds numbers as large as (Bernardini et al. 2014) and (Pirrozoli et al. 2021) are now available. Nevertheless, the case by Kim et al. still remains as a benchmark case for wall bounded turbulent flow simulations.
Description of the test case
An idealised channel flow, without side walls, is considered. The details of the case are given in Iyer et al.(2019)[2]. The current set of simulations has a higher grid resolution in the wall normal direction.
Geometry and flow parameters
The geometry is a cuboid of dimensions units in the streamwise direction , 2 units in the transverse direction and units in the spanwise direction . The dimensions are normalised by the channel half-width, and centreline velocity.
Boundary conditions
The domain is periodic in the streamwise and spanwise directions which gives a flow developing in time. The transverse boundaries are viscous walls with no-slip boundary conditions. The initial density and pressure fields are uniform. The initial velocity field is . The solution is started at order 2 and progressively increased to order 5.
References
- ↑ Kim,J., Moin, P. and Moser, R., Turbulence statistics in fully developed channel flow at low Reynolds number, J. Fluid Mech. 177, 133-166, 1987
- ↑ A. Iyer, F. D. Witherden, S. I. Chernyshenko and P. E. Vincent, Identifying eigenmodes of averaged small-amplitude perturbations to turbulent channel flow, Journal of Fluid Mechanics, 875 (758-780), 2019
Contributed by: Arun Soman Pillai, Lionel Agostini — Imperial College London
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