January 2023
·
30 Reads
·
1 Citation
This page lists works of an author who doesn't have a ResearchGate profile or hasn't added the works to their profile yet. It is automatically generated from public (personal) data to further our legitimate goal of comprehensive and accurate scientific recordkeeping. If you are this author and want this page removed, please let us know.
January 2023
·
30 Reads
·
1 Citation
January 2023
·
9 Reads
January 2023
·
16 Reads
September 2020
·
200 Reads
·
15 Citations
Nuclear Engineering and Design
This article reports the experimental and DNS database that has been generated, within the framework of the EU SESAME and MYRTE projects, for various low-Prandtl flow configurations in different flow regimes. This includes three experiments: confined and unconfined backward facing steps with low-Prandtl fluids, and a forced convection planar jet case with two different Prandtl fluids. In terms of numerical data, seven different flow configurations are considered: a wall-bounded mixed convection flow at low-Prandtl number with varying Richardson number (Ri) values; a wall-bounded mixed and forced convection flow in a bare rod bundle configuration; a forced convection confined backward facing step (BFS) with conjugate heat transfer; a forced convection impinging jet for three different Prandtl fluids corresponding to two different Reynolds numbers of the fully developed planar turbulent jet; a mixed-convection cold-hot–cold triple jet configuration corresponding to Ri = 0.25; an unconfined free shear layer for three different Prandtl fluids; and a forced convection infinite wire-wrapped fuel assembly. This wide range of reference data is used to evaluate, validate and/or further develop different turbulent heat flux modelling approaches, namely simple gradient diffusion hypothesis (SGDH) based on constant and variable turbulent Prandtl number; explicit and implicit algebraic heat flux models; and a second order turbulent heat flux model. Lastly, this article will highlight the current challenges and perspectives of the available turbulence models, in different codes, for the accurate prediction of flow and heat transfer in low-Prandtl fluids.
January 2020
·
4 Reads
August 2019
·
119 Reads
·
6 Citations
This article reports the experimental and DNS database that has been generated, within the framework of the EU SESAME and MYRTE projects, for various low-Prandtl flow configurations in different flow regimes. This includes three experiments: confined and unconfined backward facing steps with low-Prandtl fluids, and a forced convection planar jet case with two different Prandtl fluids. In terms of numerical data, seven different flow configurations are considered: a wall-bounded mixed convection flow at low-Prandtl number with varying Richardson number (Ri) values; a wall-bounded mixed and forced convection flow in a bare rod bundle configuration for two different Reynolds numbers; a forced convection confined backward facing step (BFS) with conjugate heat transfer; a forced convection impinging jet for three different Prandtl fluids corresponding to two different Reynolds numbers of the fully developed planar turbulent jet; a mixed-convection cold-hot-cold triple jet configuration corresponding to Ri=0.25; an unconfined free shear layer for three different Prandtl fluids; and a forced convection infinite wire-wrapped fuel assembly. This wide range of reference data is used to evaluate, validate and/or further develop different turbulent heat flux modelling approaches, namely simple gradient diffusion hypothesis based on constant and variable turbulent Prandtl number; explicit and implicit algebraic heat flux models; and a second order turbulent heat flux model. Lastly, this article will highlight the current challenges and perspectives of the available turbulence models, in different codes, for the accurate prediction of flow and heat transfer in low-Prandtl fluids.
August 2019
·
94 Reads
·
10 Citations
Nuclear Engineering and Design
Turbulent heat transfer is a complex phenomenon that has challenged turbulence modellers over various decades. In this regard, in the recent past, several attempts have been made for the assessment and further de-velopment/calibration of the available turbulent heat flux modelling approaches. One of the main hampering factors with respect to the further assessment of these modelling approaches is the lack of reference data. In the framework of the EU SESAME and MYRTE projects, an extensive effort has been put forward to generate a wide range of reference data, both experimental and numerical, to fill this gap. In that context, this article reports the numerical database that has been generated within these projects for various liquid metal flow configurations in different flow regimes. These high fidelity numerical data include seven different flow configurations: a wall-bounded mixed convection flow at low Prandtl number with varying Richardson number (Ri) values; a wall-bounded mixed and forced convection flow in a bare rod bundle configuration; a forced convection confined backward facing step (BFS) with conjugate heat transfer; a forced convection impinging jet for three different Prandtl fluids corresponding to two different Reynolds numbers of the fully developed planar turbulent jets; a mixed-convection cold-hot-cold triple jet configuration corresponding to Ri = 0.25; an unconfined free shear layer for three different Prandtl fluids; and a forced convection infinite wire-wrapped fuel assembly. These high-fidelity numerical databases will serve the further development of turbulent heat transfer models by providing unique, new and detailed data for the thermal-hydraulic behaviour of liquid metals in various flow configurations .
March 2019
·
94 Reads
·
1 Citation
Turbulent heat transfer is an extremely complex phenomenon that has challenged turbulence modellers over various decades. In this regard, in the recent past, several attempts have been made for the assessment and further development/calibration of the available turbulent heat flux modelling approaches. One of the main hampering factors with respect to the further assessment of these modelling approaches is the lack of reference data. In the framework of the EU SESAME and MYRTE projects, an extensive effort has been put forward to generate a wide range of reference data, both experimental and numerical, to fill this gap. In that context, this article reports the numerical database that has been generated within these projects for various liquid metal flow configurations in different flow regimes. These high fidelity numerical data include seven different flow configurations: a wall-bounded mixed convection flow at low Prandtl number with varying Richardson number (R i) values; a wall-bounded mixed and forced convection flows in a bare rod bundle configuration for two different Reynolds numbers; a forced convection confined backward facing step (BFS) with conjugate heat transfer; a forced convection impinging jet for three different Prandtl fluids corresponding to two different Reynolds numbers of the fully developed planar turbulent jets; a mixed-convection cold-hot-cold triple jet configuration corresponding to R i =0.25; an unconfined free shear layer for three different Prandtl fluids; and a forced convection infinite wire-wrapped fuel assembly. These high-fidelity numerical databases will serve the further development of turbulent heat transfer models by providing unique, new and detailed data for the thermal-hydraulic behaviour of liquid metals in various flow configurations.
January 2019
·
43 Reads
·
4 Citations
... Similar considerations are valid for the velocity magnitude range. Most probable velocities in natural convection are expected in the range of cm/s in GaInSn [18] and mm/s [19] in water. Table 1 reports a summary of the fluctuations characteristics retrieved from the DNS simulation in GaInSn [18]. ...
January 2023
... On the other hand, for lower Pr number fluids (e.g. liquid metals) the available validation data are still scarce and unreliable, especially in the natural convection regime and therefore new experiments are needed for the development of numerical models [4,5,6]. Measurement of THF is challenging as it requires simultaneous measurement of velocity and temperature fluctuations. ...
September 2020
Nuclear Engineering and Design
... In the framework of the SESAME project (thermal hydraulics Simulations and Experiments for the Safety Assessment of MEtal cooled reactors), extensive effort has been put forward to generate a comprehensive reference database in order to validate available RANS CFD models for heat transfer in liquid metals (Roelofs et al., 2016;Shams et al., 2019). This paper presents the results of such effort, where the validation and the gathered reference data are limited to the flow and thermal fluctuations in low-Prandtl number fluids in a vertical backward facing step (BFS) geometry. ...
August 2019
... Shams et al. (2018) performed a quasi-DNS computation of an infinite wire-wrapped fuel assembly for an LBE coolant flow. Additionally, within the framework of EU SESAME and MYRTE, an extensive effort was put forward to generate reference database for liquid metal flows, reader are referred to see (Shams et al., 2019a). De Santis et al. (2018) performed DNS calculations addressing forced and mixed flow in a plane channel for fluids with Pr = 1, 0.1 and 0.01. ...
August 2019
Nuclear Engineering and Design
... Reynolds-Averaged Navier-Stokes (RANS), Large Eddy Simulation (LES), and Direct Numerical Simulation (DNS) are the main numerical modeling techniques for turbulent flows employed in Computational Fluid Dynamics (CFD). DNS constitutes the ground truth of simulation because the effect of every eddy is considered when the flow equations are solved (Roelofs and Shams, 2019), as the size of the smallest DNS cell is smaller than or equal to the smallest eddy size (Tiselj et al., 2019). For low Re flows, DNS simulations require between 5 and 20 million nodes and take 250 to 400 hours of supercomputer time (Doran and Doran, 2013). ...
January 2019