Investigating the Vibration Mitigation Efficiency of Tuned Sloshing Dampers Using a Two-Fluid CFD Approach
Round 1
Reviewer 1 Report
The paper compares the efficiency of Tuned Sloshed Dampers (TSD) with that of Tuned Mass Dampers in reducing the vibrations of a high-rise structure under wind load using results computed using two-fluid multiphase Computational Fluid Dynamics (CFD) models. Validation of the approach is performed by comparing with experimental data and a comprehensive analysis of the TSD for a model building under different wind load conditions are presented. The paper is well written with details of the mathematical formulation of TSD and TMD adequately described. Where relevant, the necessary citations have been provided.
The only recommendation from this reviewer is to include the following additional details about the CFD results:
- Computational cost of a representative case with information on the mesh resolution and grid convergence of the results
- Contour plots of the two-fluid interface for a representative configuration used in Section 3.2
The above details would improve the quality of the paper and also inform the readers about the necessary details to reproduce the results if they so desire.
Author Response
Thank you for your review. Figures 5 and 12 were added to show representative numerical results for TSDs by CFD. We did this not only for the imposed motion studies, but also for the fully-coupled simulation. Density depiction is deemed best to help identify the border between water and air, which basically represents the wave. Other results (such as velocity and pressure fields) are more suitable to actually quantify forces and areas where screens should be placed, but possibly less intuitive (and even relevant) for readers to interpret. The detailed numerical setup is presented in Pentek (2018) and Riedl (2021). We particularly chose the CAARC-B building, as various other works support it with reference results as well as comprehensive data on proper numerical setups. Most relevant sources we specifically mention, additionally using the work of Krabbenhoft (2011) on validating the shallow water motion. For application purposes, we now include the problem size (as the number of numerical mesh nodes and degrees of freedom) as well the approximate CPUh (compute core hours as a measure of numerical effort). This information should support not only the reproducibility of the simulations but also help judge on the approximate numerical effort necessary.- CFD results: Added Figure 5 to Subsection 3.2, to qualitatively show the sloshing motion, best visualized by the border between densities of the two-phase flow. Here 9 time steps are chosen, with a wave travelling from the left to the right wall (a partial cycle).
- In general computational results: Added Figure 12 to Section 4, which additionally shows the types of outcomes using a coupled numerical workflow. This is complementary to Figure 9 (former numbering: 8).
- Tables 5 and 6: Summarize the model complexity as well as the numerical effort. These should provide a good starting point for those evaluating similar simulations.
Reviewer 2 Report
Interseting paper, will add to the community. Well written and organized manuscript.
Author Response
Thank you for your review. Please see various improvements to formulation and style. There is also some new content, which should add to the value of our contribution.
Reviewer 3 Report
the work is interesting as an application case of the method.The reading is difficult because the general scheme of the work is not clear from the beginning. it is advisable to divide the paragraphs better. In the conclusions, in my opinion, it must be emphasized which is the main result of the work and which are the innovative aspects. The references are almost all from many years ago, they need to be integrated with more recent literature.
Author Response
Thank you for your review. Various references were indeed lacking. Certain works on wind engineering and respective numerical models are included to support specific remarks and assumptions. More recent contributions from various authors are mentioned, which discuss multiple application cases of wave motion studies and loading due to sloshing. Currently there seems to be a general explorative effort in the broader community, where various CFD models are investigated for their suitability for particular uses cases. Additional developments are necessary to make application possible. Our contribution is particularly applying a certain two-fluid CFD formulation for the purpose of modelling a TSD, as part of a full-interaction framework with the excitation source and underlying structure. We made the effort of supporting these ideas not only by adding proper literature, but also improving overall formulation as well as amending with certain additional results (Figures 5 and 12 - also as part of the request from Reviewer 1) and a dedicated paragraph in Conclusions. The text is currently structured by starting with input related on how to model TSDs, followed by validating the chosen CFD model. This is continued by describing the characteristic load case of wind and how this can be assessed numerically, capturing the effect of AMDs on the vibrating structure. The work ends in supplying all relevant results. We believe this is a proper structuring and are certain that recent additions will aid understanding.- Added reference literature:
- on modelling sloshing motion and/or multiphase flows: Godderidge (2009), Iaconeta (2019), Cremonesi (2020), Wang (2020), Li (2021), Hwang (2021), Maso (2022),
- on wind-related aspects including numerical models: Bitsuamlak (2010), Hucho (2011), Tamura (2013), Blocken(2015), Holmes (2015), Cotela (2016),
- on numerical coupling using partitioned schemes: Heil (2008), Degroote (2010)
- Added additional comments related to the scope and clear outcome: Included an extra paragraph to the conclusions the emphasize the contribution and innovation in a concise manner. This is followed by the more lengthy summary of the work.
Round 2
Reviewer 3 Report
Ready for be published
