Constantinos Condaxakis - Academia.edu (original) (raw)
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Papers by Constantinos Condaxakis
Http Www Theses Fr, 2000
Nous proposons une demarche qui permet de diminuer le cout de l'energie produite par une eoli... more Nous proposons une demarche qui permet de diminuer le cout de l'energie produite par une eolienne, en augmentant les performances de l'aerogenerateur, element principal du systeme eolien. Nous y associons une reduction du cout de fabrication et de maintenance, pour que l'exploitation de l'energie eolienne soit economiquement viable. Le controle passif dans le domaine des systemes eoliens, se fonde sur la possibilite de l'aerogenerateur de sentir le vent, d'une certaine facon, et d'en suivre les variations de la vitesse. Son application exige l'etude aeroelastique du rotor, la definition du comportement aeroelastique d'une bande de la pale (profil d'aile) de longueur infiniment petite, puis d'un morceau de la pale. L’etude aeroelastique est basee sur le couplage de l'aerodynamique de la pale avec la dynamique de la structure. La conception du rotor est basee sur l'optimisation dynamique de la structure. La complexite du probleme rend incontournables l'utilisation et la mise au point d'outils de simulation du fonctionnement du rotor et de visualisation scientifique des resultats d'analyses effectuees auparavant. Ainsi visualises, les principaux parametres du fonctionnement dans le temps peuvent etre ajustes interactivement. Le concepteur arrive ainsi a mieux comprendre l'influence de ces parametres.
Engineering and Industry, 2016
Energies, Apr 20, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Renewable Energy, Dec 1, 2017
This article presents the fundamental points of the accomplished work regarding the energy upgrad... more This article presents the fundamental points of the accomplished work regarding the energy upgrading of the building of the Natural History Museum of Crete, Greece, based on a cluster of passive and active measures. The main target was the building's energy efficiency upgrading from D to Aþ rank. Among the passive measures, insulation of the building's envelope, installation of new windows and doors, construction of a green roof and planting of an outdoor space at the south side of the building to improve the ambient climate locally are included. Furthermore, small wind turbines and a photovoltaic station on the roof, geothermal heat pumps with an open loop system operating with seawater, new lighting equipment controlled by a central management system and reactive power coefficient compensation constitute the proposed active systems. Energy saving percentages from 40% to 93% are achieved with all the proposed technologies. In total, the primary energy specific consumption is reduced from 273.65 kWh/ m 2 at 18.36 kWh/m 2 , giving a total energy saving percentage of 93.29%. The building's energy efficiency is upgraded from the rank D to the rank Aþ, according to the European Union's standards. The total cost of the proposed measures is estimated approximately at 900,000V.
Applied Energy, Oct 1, 2019
• Pumped Storage, lead-acid and lithium-ion batteries are compared for small islands. • Pumped St... more • Pumped Storage, lead-acid and lithium-ion batteries are compared for small islands. • Pumped Storage can support long autonomy operation period and secure energy supply. • All systems can offer economically feasible solutions for small islands. • A 90% drop in the lithium-ion batteries price can trigger investors' interest. • Pumped Storage can be feasible for small islands under favorable land morphology.
Energies
This article proposes a mixture of actions for the development of an effective and rational energ... more This article proposes a mixture of actions for the development of an effective and rational energy transition plan for all sectors and for all types of onshore final energy use in Crete. Energy transition is initiated with an appropriate capacity building campaign. The plan is based on the introduction of energy saving measures and the exploitation of all the locally available energy resources (wind, solar, geothermal potential, biomass), integrated in a cluster of centralized and decentralized power plants and smart grids to produce electricity and heat and for the transition to e-mobility. The core of the energy transition in Crete will be a set of 14 wind parks and Pumped Hydro Storage systems (PHS) for electricity generation and 12 Combined Heat and Power plants, properly designed and dispersed in the insular territory. Economic analysis is executed for the proposed essential power plants on the island. Biomass, solar and geothermal potential can cover the heating demand in Cret...
The fractures of the upper end of the femur presents one of the most important medico-social prob... more The fractures of the upper end of the femur presents one of the most important medico-social problems in the developed countries of Europe and North America and the developed and under development countries of Asia and other areas of our planet. It is a real epidemic with an increasing rate, higher than the rate expected, due to the increasing elderly population. The mortality rate, the complications and in general the social, and economic cost of these injuries are particularly high. The hip fractures in 1999 were 800 in Crete and 16000 were estimated in Greece. Ninety-five percent of these fractures are due to falls mainly within the house and 80% occur to individuals over the age of 70 years. During last decade, the need to prevent fractures and protect the elderly against falls led to the design and production of hip protectors. The design concept of a hip protector aiming to protect the hip during a fall is the object of this study. The beginning of our project was the biomecha...
Renewable Energy, 2017
This article presents the fundamental points of the accomplished work regarding the energy upgrad... more This article presents the fundamental points of the accomplished work regarding the energy upgrading of the building of the Natural History Museum of Crete, Greece, based on a cluster of passive and active measures. The main target was the building's energy efficiency upgrading from D to Aþ rank. Among the passive measures, insulation of the building's envelope, installation of new windows and doors, construction of a green roof and planting of an outdoor space at the south side of the building to improve the ambient climate locally are included. Furthermore, small wind turbines and a photovoltaic station on the roof, geothermal heat pumps with an open loop system operating with seawater, new lighting equipment controlled by a central management system and reactive power coefficient compensation constitute the proposed active systems. Energy saving percentages from 40% to 93% are achieved with all the proposed technologies. In total, the primary energy specific consumption is reduced from 273.65 kWh/ m 2 at 18.36 kWh/m 2 , giving a total energy saving percentage of 93.29%. The building's energy efficiency is upgraded from the rank D to the rank Aþ, according to the European Union's standards. The total cost of the proposed measures is estimated approximately at 900,000V.
Energies
The current work focuses on establishing the parameters that influence the wind’s behavior over t... more The current work focuses on establishing the parameters that influence the wind’s behavior over the Aegean and Ionian Seas and estimating the wind potential in the region based on long-term historic climate data. Combining a downscaling technique performed with the well-founded WRF-ARW computational algorithm and a number of simultaneous meteorological station time series, an attempt is made to investigate how regional changes may affect low-altitude wind speed distribution at hub height (100 m a.s.l.). The provided time-series coastal data span the entire region of interest from north to south. WRF-ARW v.3.9 is utilized to associate the geostrophic wind distribution obtained from long-term Copernicus ERA5 wind data with the localized wind potential over lower altitudes. Evaluation and correlation of the observational data to the predicted wind climate are performed, and the statistical differences that arise are investigated. High-accuracy wind resource potential maps are thus obta...
Http Www Theses Fr, 2000
Nous proposons une demarche qui permet de diminuer le cout de l'energie produite par une eoli... more Nous proposons une demarche qui permet de diminuer le cout de l'energie produite par une eolienne, en augmentant les performances de l'aerogenerateur, element principal du systeme eolien. Nous y associons une reduction du cout de fabrication et de maintenance, pour que l'exploitation de l'energie eolienne soit economiquement viable. Le controle passif dans le domaine des systemes eoliens, se fonde sur la possibilite de l'aerogenerateur de sentir le vent, d'une certaine facon, et d'en suivre les variations de la vitesse. Son application exige l'etude aeroelastique du rotor, la definition du comportement aeroelastique d'une bande de la pale (profil d'aile) de longueur infiniment petite, puis d'un morceau de la pale. L’etude aeroelastique est basee sur le couplage de l'aerodynamique de la pale avec la dynamique de la structure. La conception du rotor est basee sur l'optimisation dynamique de la structure. La complexite du probleme rend incontournables l'utilisation et la mise au point d'outils de simulation du fonctionnement du rotor et de visualisation scientifique des resultats d'analyses effectuees auparavant. Ainsi visualises, les principaux parametres du fonctionnement dans le temps peuvent etre ajustes interactivement. Le concepteur arrive ainsi a mieux comprendre l'influence de ces parametres.
Engineering and Industry, 2016
Energies, Apr 20, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Renewable Energy, Dec 1, 2017
This article presents the fundamental points of the accomplished work regarding the energy upgrad... more This article presents the fundamental points of the accomplished work regarding the energy upgrading of the building of the Natural History Museum of Crete, Greece, based on a cluster of passive and active measures. The main target was the building's energy efficiency upgrading from D to Aþ rank. Among the passive measures, insulation of the building's envelope, installation of new windows and doors, construction of a green roof and planting of an outdoor space at the south side of the building to improve the ambient climate locally are included. Furthermore, small wind turbines and a photovoltaic station on the roof, geothermal heat pumps with an open loop system operating with seawater, new lighting equipment controlled by a central management system and reactive power coefficient compensation constitute the proposed active systems. Energy saving percentages from 40% to 93% are achieved with all the proposed technologies. In total, the primary energy specific consumption is reduced from 273.65 kWh/ m 2 at 18.36 kWh/m 2 , giving a total energy saving percentage of 93.29%. The building's energy efficiency is upgraded from the rank D to the rank Aþ, according to the European Union's standards. The total cost of the proposed measures is estimated approximately at 900,000V.
Applied Energy, Oct 1, 2019
• Pumped Storage, lead-acid and lithium-ion batteries are compared for small islands. • Pumped St... more • Pumped Storage, lead-acid and lithium-ion batteries are compared for small islands. • Pumped Storage can support long autonomy operation period and secure energy supply. • All systems can offer economically feasible solutions for small islands. • A 90% drop in the lithium-ion batteries price can trigger investors' interest. • Pumped Storage can be feasible for small islands under favorable land morphology.
Energies
This article proposes a mixture of actions for the development of an effective and rational energ... more This article proposes a mixture of actions for the development of an effective and rational energy transition plan for all sectors and for all types of onshore final energy use in Crete. Energy transition is initiated with an appropriate capacity building campaign. The plan is based on the introduction of energy saving measures and the exploitation of all the locally available energy resources (wind, solar, geothermal potential, biomass), integrated in a cluster of centralized and decentralized power plants and smart grids to produce electricity and heat and for the transition to e-mobility. The core of the energy transition in Crete will be a set of 14 wind parks and Pumped Hydro Storage systems (PHS) for electricity generation and 12 Combined Heat and Power plants, properly designed and dispersed in the insular territory. Economic analysis is executed for the proposed essential power plants on the island. Biomass, solar and geothermal potential can cover the heating demand in Cret...
The fractures of the upper end of the femur presents one of the most important medico-social prob... more The fractures of the upper end of the femur presents one of the most important medico-social problems in the developed countries of Europe and North America and the developed and under development countries of Asia and other areas of our planet. It is a real epidemic with an increasing rate, higher than the rate expected, due to the increasing elderly population. The mortality rate, the complications and in general the social, and economic cost of these injuries are particularly high. The hip fractures in 1999 were 800 in Crete and 16000 were estimated in Greece. Ninety-five percent of these fractures are due to falls mainly within the house and 80% occur to individuals over the age of 70 years. During last decade, the need to prevent fractures and protect the elderly against falls led to the design and production of hip protectors. The design concept of a hip protector aiming to protect the hip during a fall is the object of this study. The beginning of our project was the biomecha...
Renewable Energy, 2017
This article presents the fundamental points of the accomplished work regarding the energy upgrad... more This article presents the fundamental points of the accomplished work regarding the energy upgrading of the building of the Natural History Museum of Crete, Greece, based on a cluster of passive and active measures. The main target was the building's energy efficiency upgrading from D to Aþ rank. Among the passive measures, insulation of the building's envelope, installation of new windows and doors, construction of a green roof and planting of an outdoor space at the south side of the building to improve the ambient climate locally are included. Furthermore, small wind turbines and a photovoltaic station on the roof, geothermal heat pumps with an open loop system operating with seawater, new lighting equipment controlled by a central management system and reactive power coefficient compensation constitute the proposed active systems. Energy saving percentages from 40% to 93% are achieved with all the proposed technologies. In total, the primary energy specific consumption is reduced from 273.65 kWh/ m 2 at 18.36 kWh/m 2 , giving a total energy saving percentage of 93.29%. The building's energy efficiency is upgraded from the rank D to the rank Aþ, according to the European Union's standards. The total cost of the proposed measures is estimated approximately at 900,000V.
Energies
The current work focuses on establishing the parameters that influence the wind’s behavior over t... more The current work focuses on establishing the parameters that influence the wind’s behavior over the Aegean and Ionian Seas and estimating the wind potential in the region based on long-term historic climate data. Combining a downscaling technique performed with the well-founded WRF-ARW computational algorithm and a number of simultaneous meteorological station time series, an attempt is made to investigate how regional changes may affect low-altitude wind speed distribution at hub height (100 m a.s.l.). The provided time-series coastal data span the entire region of interest from north to south. WRF-ARW v.3.9 is utilized to associate the geostrophic wind distribution obtained from long-term Copernicus ERA5 wind data with the localized wind potential over lower altitudes. Evaluation and correlation of the observational data to the predicted wind climate are performed, and the statistical differences that arise are investigated. High-accuracy wind resource potential maps are thus obta...