Ricardo Jónatas

Mr. Ricardo Jónatas

orcid

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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15 July 2019 in Water Science & Technology
Verified
Journal Article
Open access
JFJoão Nuno Fernandes
João Nuno Fernandes
RJRicardo Jónatas
Ricardo Jónatas
Connecting storm-sewers located at rather different elevations may be made with vortex drop shafts in which the energy dissipation is made by the friction between the vertical shaft and the flow and downstream by the impinging jet in a dissipation chamber. Following the first model design in the 1940s, different types of vortex drop shafts have been developed. One of the most used type is the so-called spiral vortex drop shaft developed to work in supercritical flow with good performance in both energy dissipation and space constrains. In this paper, an experimental flow characterization in a spiral vortex drop shaft is conducted covering the three main components of these structures, namely the inlet channel, the vertical shaft and the dissipation chamber. The results include measurement of water depths, pressure and velocity.

1 November 2025 in Journal of Hydraulic Engineering
Verified
Journal Article
Closed access
RJRicardo Jónatas
Ricardo Jónatas
RARui Aleixo
Rui Aleixo
SASílvia Rute Caleiro Amaral
Sílvia Rute Caleiro Amaral
SMSolange Valente Mendes
Solange Valente Mendes
MVMaria Teresa Fontelas Santos Viseu
Maria Teresa Fontelas Santos Viseu
Rui M.L. FerreiraRui M.L. Ferreira
Rui M.L. Ferreira

1 June 2018 in Slovak Journal of Civil Engineering
Verified
Journal Article
Open access
PDF file
RLRute Maria Lemos
Rute Maria Lemos
MHMaria Henriques
Maria Henriques
António MuralhaAntónio Muralha
António Muralha
RJRicardo Jónatas
Ricardo Jónatas
CFConceição Juana Espinosa Morais Fortes
Conceição Juana Espinosa Morais Fortes
RCRui Capitão
Rui Capitão
This paper focuses on a study of different methodologies for surveying two-dimensional scale models of rubble mound breakwaters. Tests were conducted in one of the LNEC’s irregular wave flumes and involved the use of four different methodologies using photogrammetric and 3D scanning techniques. This paper describes the materials and methods used during the experiments, as well as the results obtained. The data analysis contains the profiles and comparison of the meshes used in each of the techniques, in order to evaluate their application in scale model tests of rubble mound breakwaters. Also, the specific experimental conditions needed for using each of these techniques were investigated.

5 December 2025 in Infrastructures
Verified
Journal Article
Open access
PDF file
RJRicardo Jónatas
Ricardo Jónatas
SASílvia Rute Caleiro Amaral
Sílvia Rute Caleiro Amaral
RARui Aleixo
Rui Aleixo
JSJoão Bilé Serra
João Bilé Serra
Rui M.L. FerreiraRui M.L. Ferreira
Rui M.L. Ferreira
Embankment structures in civil engineering, such as earth dams and fluvial dikes, have a crucial role in society. These structures, often used for water storage and mining tailing containment, are cost-effective due to their reliance on locally sourced materials. While the failure of concrete structures is not so frequent but often lead to severe consequences, embankment structures, particularly fluvial dikes, are more prone to breach and the consequences vary from mild to catastrophic, depending on the proximity to human populations. Worldwide, some fluvial dike failures have resulted in catastrophic outcomes for human lives, the local economy and the environment. This paper aims to develop a methodology to calculate in situ breach outflow hydrographs, resorting to real-time, non-intrusive and friendly access technology. The goal is to provide a practical platform for developing and testing integrated systems applicable to prototype failure cases. An accurate, real-time hydrograph estimation capacity improves risk assessment. The proposed methodology deploys, in a medium-scale experimental facility, common technology and data processing techniques to characterize the evolution of a fluvial dike failure. The morphodynamic and hydrodynamic components influencing the in situ breach outflow hydrograph are assessed by characterizing, in real-time, the breach morphology at the surface and underwater, the surface velocity maps and the corresponding cartesian coordinates.