| 1. |
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| 2. |
- Bensow, Rickard, 1972, et al.
(författare)
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An acoustic analogy and scale-resolving flow simulation methodology for the prediction of propeller radiated noise
- 2016
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Ingår i: Symposium on Naval Hydrodynamics.
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Konferensbidrag (refereegranskat)abstract
- A methodology for the prediction of underwater radiated noise from ships is presented and applied to a configuration of a cavitating propeller, operating in behind condition. A scale resolved incompressible Large Eddy Simulation technique together with an acoustic analogy is em- ployed, with cavitation represented through a mixture assumption using a volume of fluid approach and explicit mass transfer modelling. The main configuration studied is the catamaran hull and propeller of a small research vessel in model scale. The hull and a complete geometrical model of the propeller is included, while the free surface is neglected in the simulation. Results of radiated noise from the complete configuration are presented and com- pared with experimental data. Further, as an intermediate step, the propeller alone on inclined shaft is studied for both cavitating and non-cavitating conditions.
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| 3. |
- Jalkanen, Jukka-Pekka, et al.
(författare)
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Modeling of ships as a source of underwater noise
- 2017
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Shipping as a source of underwater noise is increasing. Underwater noise emission levels are seldom considered as a ship design parameter unless low vessel noise is specifically required, like in the case of warships and research vessels. Noise emissions are not regulated yet, but the awareness of possible impacts of noise on marine life is increasing. This paper describes the implementation of a noise source model for the Ship Traffic Emission Abatement Model (STEAM; Jalkanen et al. 2009; 2012; Johansson et al, 2017). The combination of vessel technical description and activity can be used to generate noise source maps which are based on actual ship traffic data. The generated noise source maps can ve used to describe the energy emitted as noise to the water, which facilitates regular annual updates of the noise emissions from ship traffic in the Baltic Sea area.
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| 4. |
- Jalkanen, J. P., et al.
(författare)
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Modelling of ships as a source of underwater noise
- 2018
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Ingår i: Ocean Science. - : Copernicus GmbH. - 1812-0792 .- 1812-0784. ; 14:6, s. 1373-1383
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, a methodology is presented for modelling underwater noise emissions from ships based on realistic vessel activity in the Baltic Sea region. This paper combines the Wittekind noise source model with the Ship Traffic Emission Assessment Model (STEAM) in order to produce regular updates for underwater noise from ships. This approach allows the construction of noise source maps, but requires parameters which are not commonly available from commercial ship technical databases. For this reason, alternative methods were necessary to fill in the required information. Most of the parameters needed contain information that is available during the STEAM model runs, but features describing propeller cavitation are not easily recovered for the world fleet. Baltic Sea ship activity data were used to generate noise source maps for commercial shipping. Container ships were recognized as the most significant source of underwater noise, and the significant potential for an increase in their contribution to future noise emissions was identified.
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| 5. |
- Karasalo, I., et al.
(författare)
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Estimates of source spectra of ships from long term recordings in the Baltic sea
- 2017
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Ingår i: Frontiers in Marine Science. - : Frontiers Media SA. - 2296-7745. ; 4:JUN
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Tidskriftsartikel (refereegranskat)abstract
- © 2017 Karasalo, östberg, Sigray, Jalkanen, Johansson, Liefvendahl and Bensow. Estimates of the noise source spectra of ships based on long term measurements in the Baltic sea are presented. The measurement data were obtained by a hydrophone deployed near a major shipping lane south of the island öland. Data from over 2,000 close-by passages were recorded during a 3 month period from October to December 2014. For each passage, ship-to-hydrophone transmission loss (TL) spectra were computed by sound propagation modeling using 1. bathymetry data from the Baltic Sea Bathymetry Database (BSBD), 2. sound speed profiles from the HIROMB oceanographic model, 3. seabed parameters obtained by acoustic inversion of data from a calibrated source, and 4. AIS data providing information on each ship's position. These TL spectra were then subtracted from the received noise spectra to estimate the free field source level (SL) spectra for each passage. The SL were compared to predictions by some existing models of noise emission from ships. Input parameters to the models, including e.g., ship length, width, speed, displacement, and engine mass, were obtained from AIS (Automatic Identification System) data and the STEAM database of the Finnish Metereological Institute (FMI).
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| 6. |
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| 7. |
- Liefvendahl, Mattias, et al.
(författare)
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Grid generation for wall-modelled les of ship hydrodynamics in model scale
- 2017
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Konferensbidrag (refereegranskat)abstract
- An unstructured grid generation approach for wall-modelled LES is proposed. The applicability of the approach is demonstrated for the simulation of the flow around an axisymmetric body, at Re-number 5.48·106, which is representable of model scale ship hydrodynamics. A numerical trip wire must be employed to induce resolved fluctuations in the simulated boundary layer. The predictive accuracy of the simulation technique is evaluated for the flow around the axisymmetric body, and for the computation of a turbulent boundary layer on a flat plate. For the flat plate, comparison is made with results from direct numerical simulation. For the axisymmetric body, results from wall-modelled LES, RANS and experimental measurements are compared.
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| 8. |
- Liefvendahl, Mattias, et al.
(författare)
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Grid requirements for LES of ship hydrodynamics in model and full scale
- 2017
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Ingår i: Ocean Engineering. - : Elsevier Ltd. - 0029-8018 .- 1873-5258. ; 143, s. 259-268
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Tidskriftsartikel (refereegranskat)abstract
- A review is presented of estimates for the grid resolution requirements for wall-resolved and wall-modeled large-eddy simulation, of flows with an important influence of turbulent boundary layers. The estimates are described within a classification scheme which is formulated based on the grid resolution relative to the length scales of the turbulent boundary layer. The grid resolution estimates are then applied to discuss the computational cost of ship hull hydrodynamics simulations, both in model and in full scale. The hulls of one submarine and one bulk carrier are included in this discussion. Two simulation cases are included in the paper to demonstrate a complete simulation methodology, to illustrate the implications of the grid resolution estimates, and to investigate the resulting predictive accuracy. The first simulation case consists of fully developed turbulent channel flow, for which a comparison is made with direct numerical simulation results. The second simulation case consists of the flow around an axisymmetric body, which is based on a bare-hull version of a generic submarine model, and for which wind tunnel measurement data are available for validation.
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| 9. |
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| 10. |
- Liefvendahl, Mattias, 1971, et al.
(författare)
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Simulation-Based Analysis of Flow-Generated Noise from Cylinders with Different Cross-Sections
- 2018
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Ingår i: Symposium on Naval Hydrodynamics Proceedings.
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Konferensbidrag (refereegranskat)abstract
- The flow-generated sound from cylinders with different cross-sections have been investigated using large-eddy simulation and an acoustic analogy. Three cylinders were investigated, with circular, square or elliptical cross-section respectively. The flow is in the sub-critical range and at low Mach number, and the source is acoustically compact. The flow around the cylinders exhibit significant differences, which are qualitatively investigated in detail. The vortex shedding frequency, the lift force fluctuations and the spanwise correlation, which are most important for noise generation, are computed for the three cases with large-eddy simulation. The resulting sound predictions are compared with aero-acoustic measurements and predictions of a semi-empirical model for the radiated sound. The semi-empirical model also provides a means for scaling of the sound results to other cylinder dimensions, flow speeds, and also for the transfer of results from air to water.
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| 11. |
- Liefvendahl, Mattias
(författare)
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Simulation of flow noise generated by the interaction of inflow turbulence with the leading edge of a foil
- 2019
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Konferensbidrag (refereegranskat)abstract
- Noise generated by the interaction of inflow turbulence with a lifting surface may be of interest for a number of hydrodynamic applications, including a propeller operating in non-cavitating condition. In the present work, simulation-based methods are applied for the prediction of the radiated noise from a wing in strong inflow turbulence, at a chord-based Reynolds number, Rec = 256000, and a Mach number of 0.09. The case has also been investigated experimentally, and a comparison is made between measurement and simulation results. Large-eddy simulation is employed to predict the flow, with synthetic turbulence fluctuations applied at the inflow boundary. The LES-results are then used to compute the acoustic source terms of an acoustic analogy. The sensitivity of the results to inflow turbulence level and turbulent length scale is investigated. The analysis is focused on the unsteady flow features associated with flow noise generation.
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| 12. |
- Mukha, Timofey, et al.
(författare)
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A library for wall-modelled large-eddy simulation based on OpenFOAM technology
- 2019
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Ingår i: Computer Physics Communications. - : Elsevier B.V.. - 0010-4655 .- 1879-2944. ; 239, s. 204-224
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Tidskriftsartikel (refereegranskat)abstract
- This work presents a feature-rich open-source library for wall-modelled large-eddy simulation (WMLES), which is a turbulence modelling approach that reduces the computational cost of standard (wall-resolved) LES by introducing special treatment of the inner region of turbulent boundary layers (TBLs). The library is based on OpenFOAM and enhances the general-purpose LES solvers provided by this software with state-of-the-art wall modelling capability. The included wall models belong to the class of wall-stress models that account for the under-resolved turbulent structures by predicting and enforcing the correct local value of the wall shear stress. A review of this approach is given, followed by a detailed description of the library, discussing its functionality and extensible design. The included wall-stress models are presented, based on both algebraic and ordinary differential equations. To demonstrate the capabilities of the library, it was used for WMLES of turbulent channel flow and the flow over a backward-facing step (BFS). For each flow, a systematic simulation campaign was performed, in order to find a combination of numerical schemes, grid resolution and wall model type that would yield a good predictive accuracy for both the mean velocity field in the outer layer of the TBLs and the mean wall shear stress. The best result, â1% error in the above quantities, was achieved for channel flow using a mildly dissipative second-order accurate scheme for the convective fluxes applied on an isotropic grid with 27000 cells per ÎŽ 3 -cube, where ÎŽ is the channel half-height. In the case of flow over a BFS, this combination led to the best agreement with experimental data. An algebraic model based on Spalding’s law of the wall was found to perform well for both flows. On the other hand, the tested more complicated models, which incorporate the pressure gradient in the wall shear stress prediction, led to less accurate results. Program Summary: Program Title: libWallModelledLES Program Files doi: http://dx.doi.org/10.17632/m8dnsnp4nd.1 Licensing provisions: GPLv3 Programming language: C++ Nature of problem: Large-eddy simulation (LES) is a scale-resolving turbulence modelling approach providing a high level of predictive accuracy. However, LES of high Reynolds number wall-bounded flows is prohibitively computationally expensive due to the need for resolving the inner region of turbulent boundary layers (TBLs) [1]. This inhibits the application of LES to many industrially relevant flows [2] and prompts for the development of novel modelling techniques that would modify the LES approach in a way that allows it to retain its accuracy (at least away from walls) yet significantly lower its computational cost. Solution method: Wall-modelled LES (WMLES) is an approach that is based on complementing LES with special near-wall modelling that allows to leave the inner layer of TBLs unresolved by the computational grid. Many types of wall models have been proposed [1,3], commonly tested within the framework of in-house research codes. Here, an open-source library implementing several wall models is presented. The library is based on OpenFOAM, which is currently the most widely used general-purpose open-source software for computational fluid dynamics
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| 13. |
- Mukha, Timofey, et al.
(författare)
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Eddylicious : A Python package for turbulent inflow generation
- 2018
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Ingår i: SoftwareX. - : Elsevier B.V.. - 2352-7110. ; 7, s. 112-114
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Tidskriftsartikel (refereegranskat)abstract
- A Python package for generating inflow for scale-resolving computer simulations of turbulent flow is presented. The purpose of the package is to unite existing inflow generation methods in a single code-base and make them accessible to users of various Computational Fluid Dynamics (CFD) solvers. The currently existing functionality consists of an accurate inflow generation method suitable for flows with a turbulent boundary layer inflow and input/output routines for coupling with the open-source CFD solver OpenFOAM.
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| 14. |
- Mukha, Timofey
(författare)
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Inflow generation for scale-resolving simulations of turbulent boundary layers
- 2016
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Generating inflow fields for scale-resolving simulations of turbulent flow is crucial for a wide range of applications and is an active area of research. In this thesis, a method for inflow generation employing a precursor turbulent channel flow simulation is proposed. A procedure for determining the parameters of the precursor simulation based on the properties of the inflow is given. To evaluate the performance of the method, results from a simulation of a flat-plate zero-pressure-gradient turbulent boundary layer are analysed. The adaption length is quantified in terms of the development of integral quantities and the statistical moments of the velocity field. The performance is also compared with that of a state-of-the-art rescaling method for the generation of inflow data. It is shown that both approaches result in adaption lengths of comparable sizes, which makes the proposed method an attractive alternative due to its conceptual simplicity and robustness.As part of the work on inflow generation, a Python package, eddylicious, was developed. The purpose of the package is to be a framework within which various generation methods can be implemented. The package is available online under an open-source license. An overview of the architecture and currently implemented functionality of the package is given in this thesis.Furthermore, the results of a preparatory study on large-eddy simulation of wall-bounded turbulent flows are discussed. Fully-developed turbulent channel flow is used as a model problem, and the general-purpose computational fluid dynamics solver OpenFOAM is employed. The accuracy of the results with respect to the resolution of the computational mesh is analysed. Several modelling approaches for the subgrid scale stresses are considered.
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| 15. |
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| 16. |
- Mukha, Timofey
(författare)
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Modelling Techniques for Large-Eddy Simulation of Wall-Bounded Turbulent Flows
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Large-eddy simulation (LES) is a highly accurate turbulence modelling approach in which a wide range of spatial and temporal scales of the flow are resolved. However, LES becomes prohibitively computationally expensive when applied to wall-bounded flows at high Reynolds numbers, which are typical of many industrial applications. This is caused by the need to resolve very small, yet dynamically important flow structures found in the inner region of turbulent boundary layers (TBLs). To remove the restrictive resolution requirements, coupling LES with special models for the flow in the inner region has been proposed. The predictive accuracy of this promising approach, referred to as wall-modelled LES (WMLES), requires further analysis and validation. In this work, systematic simulation campaigns of canonical wall-bounded flows have been conducted to support the development of a complete methodology for highly accurate WMLES on unstructured grids. Two novel algebraic wall-stress models are also proposed and shown to be more robust and precise than the classical approaches of the same type. For turbulence simulations, it is often challenging to provide accurate conditions at the inflow boundaries of the domain. Here, a novel methodology is proposed for generating an inflow TBL using a precursor simulation of turbulent channel flow. A procedure for determining the parameters of the precursor based on the Reynolds number of the inflow TBL is given. The proposed method is robust and easy to implement, and its accuracy is demonstrated to be on par with other state-of-the-art approaches. To make the above investigations possible, several software packages have been developed in the course of the work on this thesis. This includes a Python package for post-processing the flow simulation results, a Python package for inflow generation methods, and a library for WMLES based on the general-purpose software for computational fluid dynamics OpenFOAM. All three codes are publicly released under an open-source licence to facilitate their use by other research groups.
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| 17. |
- Mukha, Timofey, et al.
(författare)
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The generation of turbulent inflow boundary conditions using precursor channel flow simulations
- 2017
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Ingår i: Computers & Fluids. - : Elsevier Ltd. - 0045-7930 .- 1879-0747. ; 156, s. 21-33
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Tidskriftsartikel (refereegranskat)abstract
- The use of a precursor simulation of fully developed turbulent channel flow for the generation of turbulent boundary layer (TBL) inflow data is investigated. Based on the desired properties of the TBL, a complete procedure is described for how to specify the precursor simulation. The key feature of the specification is to match the momentum thickness of the precursor to that of the inflow TBL. The inflow data is then constructed from time- and space-dependent flow data in a cross-plane of the precursor. The proposed procedure removes the need to rescale the flow data and thus violate the governing equations, as is common practice in other state-of-the-art inflow generation methods for TBLs. The adaption length of the generated TBL is investigated using wall-resolved large-eddy simulation (WRLES) for a zero-pressure gradient (ZPG-) TBL, with a momentum thickness Reynolds number in the interval 830–2 400. The results are compared with a solution obtained using a standard rescaling procedure for the inflow data. The adaption length is shown to be similar for the two methods. Practical differences and advantages of the proposed of method, as compared to other inflow generation techniques, are assessed. These involve the role of the auxiliary simulation, channel flow in the present case, in the overall computational procedure, as well as data handling, initial transients and adaption lengths.
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| 18. |
- Rezaeiravesh, Saleh, et al.
(författare)
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A-priori study of wall modeling in large eddy simulation
- 2018
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Ingår i: Proc. 7th European Conference on Computational Fluid Dynamics. - : European Community on Computional Methods in Applied Sciences (ECCOMAS).
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Konferensbidrag (refereegranskat)
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| 19. |
- Rezaeiravesh, Saleh
(författare)
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Application of Uncertainty Quantification Techniques to Studies of Wall-Bounded Turbulent Flows
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Wall-bounded turbulent flows occur in many engineering applications. The quantities of interest (QoIs) of these flows can be accurately obtained through experimental measurements and scale-resolving numerical approaches, such as large eddy simulation (LES). However, due to the prohibitive computational costs imposed by the turbulent boundary layers (TBL) involved in these flows, the use of a standard wall-resolving (WR)LES is limited to low Reynolds (Re-) numbers. As an alternative, wall-modeled (WM)LES can be employed, in which the near-wall region of the TBL is modeled.This thesis evaluates the uncertainties involved in the measured QoIs of a set of experiments on TBLs, and also, investigates the predictive accuracy and sensitivity of LES, both wall-resolving and wall-modeled. For these purposes, different uncertainty quantification (UQ) techniques are employed.In particular, such techniques are applied to the forward (uncertainty propagation) and inverse (parameter estimation) problems involved in the measurement of mean velocity and wall shear stress using hot-wire anemometry and oil-film interferometry, respectively. The possibility of reducing epistemic uncertainties by a more detailed analysis is demonstrated. The metamodels constructed by combining non-intrusive generalized polynomial chaos expansion with the stochastic-collocation method are employed to investigate the sensitivity of WRLES of turbulent channel flow to grid resolution. This research further provides a set of recommendations for grid resolution. Through the use of a systematic simulation campaign, the predictive accuracy and sensitivity of WMLES of the same flow is investigated with respect to several influential factors. The metamodel technique is also used to explore the sensitivity to the grid anisotropy and wall model parameters. Based on this study, a set of best practice guidelines is obtained for WMLES of turbulent channel flow, the validity of which is confirmed in a wide range of Re-numbers. For all the UQ-based studies, variance-based sensitivity analysis is also performed.For WMLES, this thesis also introduces several developments in wall-stress modeling. The performance of algebraic wall-stress models is investigated in an a-priori framework, using accurate WRLES data. Two novel approaches based on integrating the wall model and dynamically adjusting its parameters are proposed and tested. This thesis also contributes to the development of an open-source library for WMLES based on OpenFOAM, which is used in the afore-mentioned systematic study for channel flow.
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| 20. |
- Rezaeiravesh, Saleh, et al.
(författare)
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Assessment of uncertainties in hot-wire anemometry and oil-film interferometry measurements for wall-bounded turbulent flows
- 2018
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Ingår i: European journal of mechanics. B, Fluids. - : Elsevier. - 0997-7546 .- 1873-7390. ; 72, s. 57-73
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Tidskriftsartikel (refereegranskat)abstract
- In this study, the sources of uncertainty of hot-wire anemometry (HWA) and oil-film interferometry (OFI) measurements are assessed. Both statistical and classical methods are used for the forward and inverse problems, so that the contributions to the overall uncertainty of the measured quantities can be evaluated. The correlations between the parameters are taken into account through the Bayesian inference with error-in-variable (EiV) model. In the forward problem, very small differences were found when using Monte Carlo (MC), Polynomial Chaos Expansion (PCE) and linear perturbation methods. In flow velocity measurements with HWA, the results indicate that the estimated uncertainty is lower when the correlations among parameters are considered, than when they are not taken into account. Moreover, global sensitivity analyses with Sobol indices showed that the HWA measurements are most sensitive to the wire voltage, and in the case of OFI the most sensitive factor is the calculation of fringe velocity. The relative errors in wall-shear stress, friction velocity and viscous length are 0.44%, 0.23% and0.22%, respectively. Note that these values are lower than the ones reported in other wall-bounded turbulence studies. Note that in most studies of wall-bounded turbulence the correlations among parameters are not considered, and the uncertainties from the various parameters are directly added when determining the overall uncertainty of the measured quantity. In the present analysis we account for these correlations, which may lead to a lower overall uncertainty estimate due to error cancellation Furthermore, our results also indicate that the crucial aspect when obtaining accurate inner-scaled velocity measurements is the wind-tunnel flow quality, which is more critical than the accuracy in wall-shear stress measurements.
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| 21. |
- Rezaeiravesh, Saleh, et al.
(författare)
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Effect of grid resolution on large eddy simulation of wall-bounded turbulence
- 2018
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Ingår i: Physics of fluids. - : American Institute of Physics Inc.. - 1070-6631 .- 1089-7666. ; 30:5
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Tidskriftsartikel (refereegranskat)abstract
- The effect of grid resolution on a large eddy simulation (LES) of a wall-bounded turbulent flow is investigated. A channel flow simulation campaign involving a systematic variation of the streamwise (Îx) and spanwise (Îz) grid resolution is used for this purpose. The main friction-velocity-based Reynolds number investigated is 300. Near the walls, the grid cell size is determined by the frictional scaling, Îx+ and Îz+, and strongly anisotropic cells, with first Îy+ ⌠1, thus aiming for the wall-resolving LES. Results are compared to direct numerical simulations, and several quality measures are investigated, including the error in the predicted mean friction velocity and the error in cross-channel profiles of flow statistics. To reduce the total number of channel flow simulations, techniques from the framework of uncertainty quantification are employed. In particular, a generalized polynomial chaos expansion (gPCE) is used to create metamodels for the errors over the allowed parameter ranges. The differing behavior of the different quality measures is demonstrated and analyzed. It is shown that friction velocity and profiles of the velocity and Reynolds stress tensor are most sensitive to Îz+, while the error in the turbulent kinetic energy is mostly influenced by Îx+. Recommendations for grid resolution requirements are given, together with the quantification of the resulting predictive accuracy. The sensitivity of the results to the subgrid-scale (SGS) model and varying Reynolds number is also investigated. All simulations are carried out with second-order accurate finite-volume-based solver OpenFOAM. It is shown that the choice of numerical scheme for the convective term significantly influences the error portraits. It is emphasized that the proposed methodology, involving the gPCE, can be applied to other modeling approaches, i.e., other numerical methods and the choice of SGS model.
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| 22. |
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| 23. |
- Rezaeiravesh, Saleh, et al.
(författare)
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On grid resolution requirements for les of wall-bounded flows
- 2016
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Ingår i: ECCOMAS Congress 2016 - Proceedings of the 7th European Congress on Computational Methods in Applied Sciences and Engineering. - Athens : National Technical University of Athens. ; 4, s. 7454-7465, s. 7454-7465
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Tidskriftsartikel (refereegranskat)abstract
- Grid requirements for LES of wall-bounded flows are considered. The setting is a zero pressure gradient turbulent boundary layer on a flat plate, but the results are intended to be of use generally for the simulation of flows with an important influence of turbulent boundary layers. The basis for the grid estimates are expressions for the thickness and the viscous length scale of a turbulent boundary layer. The literature is reviewed, and a new power law is proposed, the coefficients of which have been determined using recent high-Re experimental data. An estimation for the number of grid points required for NWM-LES is derived, which is more general than previously published such estimates. A complete simulation methodology, including a numerical tripping device for transition to turbulence in the boundary layer, is demonstrated for NWM-LES of a flat plate turbulent boundary layer. The predictive accuracy is assessed by comparison with DNS data.
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| 24. |
- Rezaeiravesh, Saleh, et al.
(författare)
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Systematic study of accuracy of wall-modeled large eddy simulation using uncertainty quantification techniques
- 2019
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Ingår i: Computers & Fluids. - : Elsevier Ltd. - 0045-7930 .- 1879-0747. ; 185, s. 34-58
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Tidskriftsartikel (refereegranskat)abstract
- The predictive accuracy of wall-modeled large eddy simulation is studied by systematic simulation campaigns of turbulent channel flow. The effect of wall model, grid resolution and anisotropy, numerical convective scheme and subgrid-scale modeling is investigated. All of these factors affect the resulting accuracy, and their action is to a large extent intertwined. The wall model is of the wall-stress type, and its sensitivity to location of velocity sampling, as well as law of the wall’s parameters is assessed. For efficient exploration of the model parameter space (anisotropic grid resolution and wall model parameter values), generalized polynomial chaos expansions are used to construct metamodels for the responses which are taken to be measures of the predictive error in quantities of interest (QoIs). The QoIs include the mean wall shear stress and profiles of the mean velocity, the turbulent kinetic energy, and the Reynolds shear stress. DNS data is used as reference. Within the tested framework, a particular second-order accurate CFD code (OpenFOAM), the results provide ample support for grid and method parameters recommendations which are proposed in the present paper, and which provide good results for the QoIs. Notably, good results are obtained with a grid with isotropic (cubic) hexahedral cells, with 15 000 cells per ÎŽ 3 , where ÎŽ is the channel half-height (or thickness of the turbulent boundary layer). The importance of providing enough numerical dissipation to obtain accurate QoIs is demonstrated. The main channel flow case investigated is Re Ï =5200, but extension to a wide range of Re-numbers is considered. Use of other numerical methods and software would likely modify these recommendations, at least slightly, but the proposed framework is fully applicable to investigate this as well.
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