Numerical modeling of wind effects in the interaction of waves with structures (Moviola).

The MOVIOLA project, currently underway, will be developed between 2012-2014 and is funded by the Spanish National Reseach Plan (DO).

The goal of this research project is to improve our knowledge and predictive capabilities related with the interaction of waves with the wind in the vicinity of coastal structures. This project stems from research lines opened during the project
MOTIOM (BIA2008 - 05462) in which we studied the three-dimensional processes developed by waves on coastal structures, focusing the analysis on rubble mound breakwaters and on wave overtopping.

Traditional analysis of the effect of wind has been simulated correctly in experimental trials in which the scaling of physical models limits the universality of the results, or from field measurements with a high spatial variability and lack of control of external variables . Although the number of jobs is not very high and has not materialized in any predictive tool as semi- empirical formulation and generally reliable , the effect of wind on the overshoot is well known , acting on the wave waves way peraltando additional and increasing rates exceeded .

The project focuses mainly on improving the modeling of the rupture with and without wind, fundamental aspect rebase to what is considered the presence of air and its effect on the wave, and improvements in the conditions of absorption waves to generate more realistic situations to improve predictive techniques . The proposed methodology intends to use three-dimensional numerical modeling of the Navier -Stokes and physical experimentation centered on vertical breakwaters exceeded . For the numerical study will be used
IH3-VOFmodel , developed within the MOTIOM project which will introduce the physics of air and which expands the range of physical processes used to study the process of wave interaction with coastal structures . The numerical results will be validated by means of experimental test campaigns designed specifically for this purpose in the CCOB, Cantabria Coastal and Ocean Basin,  equipped with a wind wave generation system. The project results will be used to improve and optimize the functional design and stability of coastal structures, reducing uncertainties caused by the wind effects on the determination of theovertopping and effort rates, whic is currently very difficult to determine, and generating a tool for quantification.

Published in R&D projects

Large scale measurements of wave loads and mapping of impact pressure distribution at the underside of parapets

Hydralab IV, More than Water: 2010 – 2014

Facility: Large Wave Channel (GWK)

The Hydralab programme aims to provide access to eclusive hydraulic structures and facilities within the EU research area.

The Hydralab IV framework has a specific call for "Large scale measurements of wave loads and mapping of impact pressure distribution at the underside of parapets". The main goal of this project is to study the pressures that broken waves have on monolithic structures. The magnitude of the forces caused by this type of impact Ees much greater than that of non broken waves. In the past however n research ahs been carried out on this specific effec t of the phenomena. The information obtained will be used, together with the measurements of the incident wave hydrodinamic conditions and the generated overtopping, to increase the knowledge on this type of phenomena and to improve the existing numerical models. (Losada et al. (2008), Lara et al. (2008)). Design guidelines will also be presented.

The following are some of the secondary goals of the project: Como objetivos parciales del proyecto se pueden detallar:

  • Measure the forces induced by the broken waves and pressures on the monolithic structure.
  • Register the velocity and thickness of the overtopping jet and relate these variables with the incident wave conditions, the localization of the structure regarding the sea level , its longitude, shape and the registered overtopping.
  • Use the obtained results in the two previous goals to improve our knowledge on these types of events as well as on the numerical models used to simulate these phenomena.
Published in R&D projects

globex1Nonlinear transformations undergone by  waves approaching the shore are accompanied by  long period  oscillations induced by the groups of waves.

A wave's nonlinearity is crucial for the transport of sediment accretion making it responsible for beach erosion. While in steep beaches nonlinear processes occur locally, the nonlinearity in extended beaches is significant, as this has the potential of developing over larger temporal and spatial scales.

Currently, there are gaps in the knowledge of many aspects of hydrodynamics related to outstretched beaches propagation and interaction of long and short waves and how these oscillations affect sediment transport. In this context, the GLOBEX (Gently sloping Beach Experiments) project was carried  out within the European program HYDRALAB. Physical experiments were conducted in the Scheldt wave flume channel located in Holland in which a beach with a concrete slope of 1:80 was built.

The goals of the project were to focus on the study of some of the main aspects of the nonlinearity of the waves, long wave dissipation in the surf zone, wave speed and boundary layer dynamics. The high spatial and temporal resolution adopted during the tests was collected in an extensive database used to improve understanding of the hydrodynamic processes in beaches.

Published in R&D projects
One of the key aspects to assessing meteorological oceanographic dynamics is to provide a simplified representation, often using probabilistic parameters and distribution functions of environmental variables.

Researchers in this group have developed, over the last 10 years, various methodologies for the univariate and multivariate definition of marine climate, under either average or extreme regime persistencies (IDF curves). As a result of this research, two recently presented doctoral theses have studied the representation of the maritime climate with data mining techniques and modeling of non-stationary wave extremes, wind, precipitation and sea level.

The generation of databases on marine variables is the basis for the analysis of climate dynamics and climate change. At IH Cantabria each database generation involves a methodological process that includes, in addition to the numerical simulation of the target variable, the validation of the simulations using instrumental measurements, calibration of the databases and characterization of the simulated climate.

That is why our wave, sea level and wind data bases have three important characteristics: quality, availability close to shore and the length of the available time series,  fundamental to the study of historical changes observed or of future climate evolution.

IH is also developing new techniques to generate databases for future climate projections with sufficient spatial resolution for regional analysis.

One of IH Cantabria's traditional lines of research has been the development of numerical models for the study of coastal processes related to both marine and sediment transport dynamics along with morphological changes on beaches.

The dynamic line marine research focuses on the study of propagation of waves, currents and sea level from turbulent processes to the processes in the larger spatial and temporal scales.

The projects carriedout in beach morphodynamics have contributed to major scientific breakthroughs, simulating both the morphology of the beaches in the short term by means of beach plan evolution (2DH) and profile (2DV) models, as well as in the understanding of the processes in the long term, through the development of beach specific models which take into consideration seasonal variability in beaches.

IH Cantabria invests heavily in knowledge transfer of scientific results to ensure that they benefit society, implementing models and working methods which are the result of research and experience and making them more user friendly. An example of this type of tool is the Coastal Modelling System SMC. The models developed adhere to a continuous process of validation and callibration using experimental testing in our lab facilities IHLabHidro and field testing through our beach monitoring systems.

El IH Cantabria ha desarrollado numerosos proyectos de investigación sobre la gestión de las inundaciones, en especial tras la publicación de la Directiva 2007/60/CE, relativa a la evaluación y la gestión de los riesgos de inundación, tanto a nivel regional como nacional e internacional.

Dentro de esta línea de investigación la labor del instituto se centra en aspectos tales como el desarrollo y utilización de herramientas matemáticas específicas (como modelos bidimensionales), el estudio estocástico de caudales extremos o el análisis hidráulico de infraestructuras. Especial mención cabe hacer aquí de los trabajos realizados sobre el establecimiento de condiciones de contorno en la desembocadura de los ríos, donde se analiza la combinación de caudales fluviales y estados de mar asociados a diferentes combinaciones de marea y oleaje.  

Por otra parte, como resultado de los avances alcanzados en este campo de investigación, el IHCantabria ha establecido un convenio de colaboración con HR Wallingford, institución de referencia a nivel mundial en este ámbito, con el fin de desarrollar un sistema de modelado integral de gestión del riesgo de inundación. Dicho sistema tiene como objetivo prioritario la incorporación en la estimación de citado riesgo de criterios de estabilidad de defensas fluviales, de valoración de costes económicos y de protección de las vidas humanas.

Published in Hydraulic Engineering
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