Comparing linear and non linear wind flow models

Assessing wind conditions on complex terrain has become a hard task as terrain complexity increases. That is why there is a need to extrapolate in a reliable manner some wind parameters that determine wind farms viability such as annual average wind speed at all hub heights as well as turbulence intensities. The development of these tasks began in the early 90´s with the widely used linear model WAsP and WAsP Engineering especially designed for simple terrain with remarkable results on them but not so good on complex orographies. Simultaneously non-linearized Navier Stokes solvers have been rapidly developed in the last decade through CFD (Computational Fluid Dynamics) codes allowing simulating atmospheric boundary layer flows over steep complex terrain more accurately reducing uncertainties. This paper describes the features of these models by validating them through meteorological masts installed in a highly complex terrain. The study compares the results of the mentioned models in terms of wind speed and turbulence intensity

Development and experimental validation of an overlay mortar with biocide activity

Biodeterioration of concrete by microorganism colonisation may be a problem in several structures, especially in irrigation and hydroelectric canals. The main problem in such structures is the proliferation of algae and cyanobacteria that affect the performance of the structure, increase the maintenance costs and affects its durability. A research was conducted to develop a novel cement-based material with biocide activity that can be used as an overlay mortar in existing structures, such as canals and pipes. With this aim, ten commercial biocides were evaluated in a laboratory campaign to assess the effectiveness of the compounds against the microbial colonisation of concrete. Both mono- and multicomponent formulations were designed from the commercial products, to increase their antimicrobial effect obtaining a set of biocide formulations. The formulations were submitted to a flowchart process to determine their influence on the physical properties of the concrete, evaluate the release of the actives, and their antimicrobial efficiency both before and after accelerated aging processes. During the campaign, some formulations were observed to diminish the strength of the concrete. Such behaviour was normally due to the interaction of the active with the cement hydration process. Other formulations showed a high release of active from the concrete in water, compromising the durability of the treatment. In general, monocomponent formulations did not succeed to fulfill all the requirements, thus multicomponent formulations were analysed. One studied multicomponent formulation presented particularly good results in all properties analysed. This product did not significantly change the properties of concrete and the release of active in water from the concrete was low, while the antimicrobial effects were long lasting.Peer ReviewedPostprint (author's final draft

Parameterization of the atmospheric boundary layer for offshore wind resource assessment with a limited length-scale k-ε model

The structure of the atmospheric boundary layer (ABL) is modelled with the limited- length-scale k-ε model of Apsley and Castro. Contrary to the standard k-ε model, the limited-length-scale k-ε model imposes a maximum mixing length which is derived from the boundary layer height, for neutral and unstable atmospheric situations, or by Monin-Obukhov length when the atmosphere is stably stratified. The model is first verified reproducing the famous Leipzig wind profile. Then the performance of the model is tested with measurements from FINO-1 platform using sonic anemometers to derive the appropriate maximum mixing length

CFD modelling of the interaction between the Surface Boundary Layer and rotor wake. Comparison of results obtained with different turbulence models and mesh strategies

A simplified CFD wake model based on the actuator disk concept is used to simulate the wind turbine, represented by a disk upon which a distribution of forces, defined as axial momentum sources, are applied on the incoming non-uniform flow. The rotor is supposed to be uniformly loaded, with the exerted forces function of the incident wind speed, the thrust coefficient and the rotor diameter. The model is tested under different parameterizations of turbulence models and validated through experimental measurements downwind of a wind turbine in terms of wind speed deficit and turbulence intensity

Validation of a CFD wake model based on the actuator disk technique and the thrust coefficient. Preliminary results

A simplified CFD wake model based on the actuator-disk concept is used to simulate the wind turbine, represented by an actuator disk upon which a distribution of forces, defined as axial momentum sources, are applied on the incoming flow. The rotor is supposed to be uniformly loaded, with the exerted forces as a function of the incident wind speed, the thrust coefficient and the rotor diameter. The model is validated through experimental measurements downwind of a wind turbine in terms of wind speed deficit. Validation on turbulence intensity will also be made in the near future

Numerical CFD modelling of non-neutral atmospheric boundary layers for offshore wind resource assessment based on Monin-Obukhov theory

The presented works aim at proposing a methodology for the simulation of offshore wind conditions using CFD. The main objective is the development of a numerical model for the characterization of atmospheric boundary layers of different stability levels, as the most important issue in offshore wind resource assessment. Based on Monin-Obukhov theory, the steady k-ε Standard turbulence model is modified to take into account thermal stratification in the surface layer. The validity of Monin-Obukhov theory in offshore conditions is discussed with an analysis of a three day episode at FINO-1 platform

Basement structure of the Hontomín CO2 storage site (Spain) determined by integration of microgravity and 3-D seismic data

A multidisciplinary study has been carried out in Hontomín (Spain) to determine the basement structural setting, its geometry and the geometry of the sedimentary succession of an area aimed to be the first Spanish pilot plant for CO2 storage. An integration of coincident 3-D seismic results, borehole data and unpublished microgravity data were used to reproduce the deep structure and topography of the basement and to quantify the thickness of the Triassic Keuper evaporites. The subsurface structure is characterized by a half-graben setting filled with Keuper evaporites (up to 2000m thick), forming an extensional forced fold. All data sets clearly identify two main fault systems, compartmentalizing the main structural domain into three differentiated blocks. These faults have been interpreted to be reactivated normal faults that have led to the formation of the Hontomín dome. © Author(s) 2016.The data sets in this work have been funded by Fundación Ciudad de la Energía (Spanish Government, www.ciuden.es) and by the European Union through the “European Energy Programme for Recovery” and the Compostilla OXYCFB300 project. Juan Alcalde is currently funded by NERC grant NE/M007251/1.Peer reviewe

Manejo reproductivo de la oveja Rasa Aragonesa: preparación de las ovejas destinadas a la inseminación artificial

raza Rasa aragonesaPublishe

Basement structure of the Hontomín CO2 Geological storage facility (Burgos, Spain): integration of microgravity & 3D seismic reflection data

The structure of the Hontomín CO2 geological storage research facility has been addressed combining 3D seismic reflection data, borehole information and microgravity data. The integrated interpretation constrains the basement structural setting geometry and that of the sedimentary succession. The study unravels the deep structure and topography of the basement and quantifies the thickness of the Triassic Keuper evaporites. We describe a half-graben setting filled with Keuper evaporites (up to 2000 m) forming an extensional forced fold. Three set of faults are identified with two main fault systems compartmentalizing the area into three differentiated blocks. These faults have been interpreted to be reactivated normal faults that have led to the formation of the Hontomín dome.The datasets in this work have been funded by Fundación Ciudad de la Energía (Spanish Government, www.ciuden.es) and by the European Union through the “European Energy Programme for Recovery” and the Compostilla OXYCFB300 project. Dr. Juan Alcalde is currently funded by NERC grant NE/M007251/1.Peer Reviewe

From the surface Topography to the Upper mantle beneath Central-Iberian-Zone. The ALCUDIA Seismic Experiments

American Geophysical Union, Fall Meeting 15-19 December, 2014, San FranciscoMulti-seismic experiments acquired across the central and southern part of the Iberian Peninsula provide a new insight into the structure and nature of the lithosphere beneath these areas. Normal incidence and wide-angle seismic reflection data acquired in the area resolve the internal architecture and constrain the distribution of the physical properties along an almost 280 km long transect that samples the major tectonic domains of the Central Iberian Zone (CIZ) and the associated suture (e.g., the Central Unit, CU). A high quality image, ~230 km long, down to 45 km depth (~15 s TWTT) is provided by the normal incidence data set. Based on the reflectivity characteristics, the image can be divided into an upper and mid-lower crust, ~13 km and ~18 km thick, respectively. The wide-angle seismic transect extended the crustal section towards the north across the Madrid Basin. This, latter data set also sample the CIZ until the CU. This is ~280 km long profile which provides very strong constraints on the distribution of physical properties (P wave and S wave velocities, Poisson's ratio) of the upper lithosphere. The PiP and PmP seismic phases constrain two discontinuities: the brittle to ductile discontinuity at ~13-19 km and the Moho boundary at ~31-35.5 km. Currently both appear to act as decoupling surfaces and are interpreted to represent levels of lithological/rheological variations. The internal structure of the Moho is further discussed taking into account the characteristics of the PmP reflections. Furthermore, low fold wide-angle P and S wave stacks reveal a marked crust-mantle transition which is most probably 5-6 km thick and relatively complex structure. The geometrical relationships of this structure with the crustal fabrics of the normal incidence image suggest that the Moho is most probably a result of the re-equilibration and/or other lithospheric processes active after the Variscan collision