Abstract

Open public spaces provide venues for cultural, recreational events and promote informal social contact between citizens. Successful outdoor spaces promote comfort and invite people to stay outdoors. Provision of thermal comfort outdoors present a challenge, as an extended range of environmental conditions must be dealt with. The present study examines whether climatic characteristics in Dublin facilitate exercising long-term outdoor activities during summer, and investigates the extent to which urban planning and the resulting urban morphology of the built environment influences microclimates created, from the viewpoint of wind environment. Microclimates at Grand Canal Square have been simulated by ENVI-met. Wind velocity has been expressed in relation to that of the “background” climate in order to verify if the site has a wind protecting character or to the contrary, it enhances airflow. The results show for the dominant wind directions (W, SW, S) that 60% higher wind velocity than at Dublin Airport can occur around building corners and at restricted flow sections—preventing any kind of long-term outdoor activity during a “typical” day. S and SW winds cause 15%–20% acceleration at the W waterfront area. Windy urban environment can call forth a limited frequentation of urban space.

Abstract

This study addresses the implementation of electrical micro-grids in urban areas as a response to the need for the insertion of renewable energies in different societies. In a first phase, the energy consumption profile of a condominium with a residential, commercial type load is characterized. and community, addressing the construction of said profile by lifting real loads and statistical criteria of use and coincidence. In the second phase, the natural resources, wind speed and solar radiation available in the study area are analyzed through the specialized software Homer Pro with latitude and longitude coordinates, subsequently the viability of the renewable electricity generation elements is analyzed and defined use, a possible generator set and its use of fuel are also proposed in order to complement the micro-grid in aspects of inertia and stability. With the energy demand and generation resources raised, architectural alternatives of a potential micro-network for the condominium are designed, simulations are carried out for isolated and interconnected cases with real values ​​of the environment and an economic analysis of the implementation, obtaining the viability of the micro network.

Abstract

This work shows results of the application of computational fluid dynamics on studying the aerodynamics of isolated curved roof buildings, without cladding walls. This type of structures are widely used in Argentine Republic in cities and and country areas, and they could be seen in very different uses, such as parking areas, sport facilities, educational buildings and so on. Current Argentinean wind loads code tells nothing about them and the same situation is found in other countries codes. Finite element program and a computer cluster were used to obtain numerical results, and a wind tunnel study undertaken at the Universidad Nacional del Nordeste boundary layer wind tunnel, to measure wind pressures on a model was used to validate computational results. A good agreement between computational and experimental results was achieved and original results for this type of structures was also obtained.

Abstract

International audience; Accurate wind magnitude and direction estimation is essential for aircraft trajectory prediction. For instance, based on these data, one may compute entry and exit time from a sector or detect potential conflict between aircraft. Since the flight path has to be computed and updated on real time for such applications, wind information has to be available in real time too. The wind data which are currently available through meteorological service broadcast suffer from small measurement rate with respect to location and time. In this paper, a new wind estimation method based on radar tracks is developed. An Extended Kalman filer extracts the wind information by observation of the radar tracks in turns. After performing many evaluations in realistic framework, our approach is able to estimate the wind vectors accurately. By this mean, each aircraft can be seen as a wind sensor when it is turning. Based on those measurements, a global space-time wind field estimation using vector splines is extrapolated in order to produce wind maps in the area of interest. The underline model for wind field computation is Shallow-Water, which assumes geostrophic wind. The accuracy of this wind map is dependent of the number of aircraft turns in a given zone; then the estimation is better in the terminal area (TMA) than in en-route area because aircraft are tuning more often. Further improvements to the estimation can be made by correlating with meteorological measurements.

Abstract

Electrical energy storage is often proposed as a solution for the mismatch between supply patterns of variable renewable electricity sources and electricity demand patterns. However, effectiveness and usefulness of storage may vary under different circumstances. This study provides an abstract perspective on the merits of electrical energy storage integrated with decentralized supply systems consisting of solar PV and wind power in a mesolevel, residential sector context. We used a balancing model to couple demand and supply patterns based on Dutch weather data and assess the resultant loads given various scenarios. Our model results highlight differences in storage effectiveness for solar PV and wind power, and strong diminishing-returns effects. Small storage capacities can be functional in reducing surpluses in overdimensioned supply systems and shortages in under-dimensioned supply systems. However, full elimination of imbalance requires substantial storage capacities. The overall potential of storage to mitigate imbalance of variable renewable energy is limited. Integration of storage in local supply systems may have self-sufficiency and cost-effectiveness benefits for prosumers but may have additional peak load disadvantages for grid operators. Adequate policy measures beyond current curtailment strategies are required to ensure proper distribution of benefits and responsibilities associated with variable renewable energy and storage.

Abstract

Electrical energy storage is often proposed as a solution for the mismatch between supply patterns of variable renewable electricity sources and electricity demand patterns. However, effectiveness and usefulness of storage may vary under different circumstances. This study provides an abstract perspective on the merits of electrical energy storage integrated with decentralized supply systems consisting of solar PV and wind power in a mesolevel, residential sector context. We used a balancing model to couple demand and supply patterns based on Dutch weather data and assess the resultant loads given various scenarios. Our model results highlight differences in storage effectiveness for solar PV and wind power, and strong diminishing-returns effects. Small storage capacities can be functional in reducing surpluses in overdimensioned supply systems and shortages in under-dimensioned supply systems. However, full elimination of imbalance requires substantial storage capacities. The overall potential of storage to mitigate imbalance of variable renewable energy is limited. Integration of storage in local supply systems may have self-sufficiency and cost-effectiveness benefits for prosumers but may have additional peak load disadvantages for grid operators. Adequate policy measures beyond current curtailment strategies are required to ensure proper distribution of benefits and responsibilities associated with variable renewable energy and storage.

Abstract

This paper explores the design profession’s evolving understanding of lateral design. It shows how the United States building codes’ handling of seismic and wind forces has changed over time, often in response to extreme events or technological developments. Prior to the early 1900s most buildings were designed without an explicitly defined lateral force resisting system. Up to that time period earthquakes and strong wind events produced little in the way of code requirements to address lateral forces. It was the advent of steel and high-rise construction in the late 19th Century that triggered a need to consider lateral loads. During the early 20th Century little consensus existed regarding the lateral forces that needed to be resisted. Wind loading provisions began appearing in the codes of large cities in the early 1900s, but it would not be until the 1930s that seismic provisions started to be codified, and then only in California. Throughout the 20th Century significant lateral events have continued to expose vulnerabilities that have been subsequently addressed with changes in construction detailing and code restrictions. In the mid-1900s regional building codes developed, focusing on the lateral hazards present in their locality. By 2000 these regional codes were replaced by a national code, and lateral design has now started to shift from prescriptive requirements towards performance-based design. This paper will help structural engineers better understand the historic building stock by exploring how lateral design has evolved in the US over the last hundred years.