scholarly journals On the use of mesh movement methods to help overcome the multi-scale challenges associated with hydro-morphodynamic modelling

2020 ◽  
Author(s):  
Mariana Clare ◽  
Joseph Wallwork ◽  
Stephan Kramer ◽  
Hilary Weller ◽  
Colin Cotter ◽  
...  
Author(s):  
Mariana C. A. Clare ◽  
Joseph G. Wallwork ◽  
Stephan C. Kramer ◽  
Hilary Weller ◽  
Colin J. Cotter ◽  
...  

AbstractHydro-morphodynamic modelling is an important tool that can be used in the protection of coastal zones. The models can be required to resolve spatial scales ranging from sub-metre to hundreds of kilometres and are computationally expensive. In this work, we apply mesh movement methods to a depth-averaged hydro-morphodynamic model for the first time, in order to tackle both these issues. Mesh movement methods are particularly well-suited to coastal problems as they allow the mesh to move in response to evolving flow and morphology structures. This new capability is demonstrated using test cases that exhibit complex evolving bathymetries and have moving wet-dry interfaces. In order to be able to simulate sediment transport in wet-dry domains, a new conservative discretisation approach has been developed as part of this work, as well as a sediment slide mechanism. For all test cases, we demonstrate how mesh movement methods can be used to reduce discretisation error and computational cost. We also show that the optimum parameter choices in the mesh movement monitor functions are fairly predictable based upon the physical characteristics of the test case, facilitating the use of mesh movement methods on further problems.


2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Paul G. Tucker

Purpose The purpose of this paper is to outline the extensive multi-scale and multi-physics challenges when simulating future aircraft and offer strategies to help deal with some of these challenges. Design/methodology/approach To help with the multi-scale challenges, in a hierarchical, zonal fashion both the handling of turbulence and geometry is considered. Findings Such modelling of geometry is necessary to help deal with the increasingly coupled nature of many aerodynamic problems more economically and the drive towards considering ever increasing levels of geometrical complexity/scale. Originality/value The proposed unified framework could be exploited all the way, through initial fast preliminary design to final numerical test involving various bespoke combinations of hierarchical components.


2020 ◽  
Vol 197 ◽  
pp. 10011
Author(s):  
Giorgio Besagni ◽  
Lorenzo Croci ◽  
Nicolò Cristiani ◽  
Gaël Raymond Guédon ◽  
Fabio Inzoli

The selection of refrigerants for ejector refrigeration systems, within the broader discussion concerning refrigerant phase-out, is a cutting-edge and challenging research topic, owing to the multi-scale challenges in ejector performance. Indeed, it is known that the performances of ejector refrigeration systems depend on the local flow phenomena. For this reason, a precise selection of the refrigerant relies on the understanding of the fluid dynamic phenomena at the “componentscale”, and integrate such information within the so-called “system-scale”. This paper contributes to the current discussion proposing a screening of refrigerants based on an integrated Computational Fluid Dynamic (CFD) Lumped Parameter Model (LPM) approach. In this approach, ejector performances for the different refrigerant are obtained by a validated CFD approach, whereas the cycle is modelled by a Lumped Parameter Model. For the different refrigerants, the energy performances of the systems are evaluated and the effects of the “component-scale” on the “system-scale” are analysed.


2016 ◽  
Vol 136 (8) ◽  
pp. 1078-1084
Author(s):  
Shoichi Takei ◽  
Shuichi Akizuki ◽  
Manabu Hashimoto

2014 ◽  
Vol 2014 (2) ◽  
pp. 60-71
Author(s):  
Peyman Mohammadmoradi ◽  
◽  
Mohammad Rasaeii ◽  

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