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- Numerical model of propeller vortex wakes for calculation of induced velocitiesPublication . Duarte, Rogério; Campos, J. A. C. Falcão deA numerical model for partial alignment of propeller vortex wakes with the flow is investigated. A lifting line representation of the propeller blades is used combined with the vortex lattice discretization method. The model takes into account radial contraction and axial variation of the pitch of the trailing vortices. The convergence of the iterative pitch alignment procedure and the influence of the number of vortex elements is studied in the case of an optimum moderately loaded propeller. The effects of axial variation of pitch and contraction are investigated for the same optimum circulation distribution case. The model is applied to the vortex wake of propeller DTRC 4119 and results are compared with experimental data.
- Energy rehabilitation studies of a large group of historical buildings: a case studyPublication . Teixeira, A. Rego; Duarte, Rogério; Brotas, L.; Almeida, P.; Brandão, M. A.In this paper, energy rehabilitation studies of a large group of historical buildings are assessed. A general methodology and some particular constraints are discussed. For a case study including 65 buildings in one of Lisbon’s historical centres, the methodology used, the proposed energy-efficient measures and the results in terms of heating energy savings and summer thermal convert are presented and discussed.
- Avaliação energética de um sistema híbrido radiante-convectivo a dois-tubos, ventiloconvectores e paredes radiantesPublication . Roriz, L.; Duarte, Rogério; Gamboa, M.A comparação dos sistemas radiantes com os sistemas convectivos tradicionais pode ser efectuada através da análise comparativa dos efeitos resultantes da elevação da temperatura radiante média e 1 K com os efeitos resultantes da elevação da temperatura do ar interior de 1 K. No presente artigo, introduz-se um sistema híbrido radiante-convectivo baseado no sistema a dois-tubos, ventiloconvectores e paredes radiantes para um edifício de escritórios. Com base no programa de simulação DOE2, obtém-se a poupança energética anual devida à alteração da temperatura do ar no interior da sala de 1 K nas estações de aquecimento e arrefecimento e apresentam-se resultados que demonstram que o consumo energético para a alteração de 1 K da temperatura radiante média é inferior a esta poupança energética. Discutem-se questões técnicas e relativas ao investimento necessário para implementar o sistema híbrido radiante-convectivo. Os resultados permitem concluir o interesse deste sistema híbrido radiante-convectivo.
- Glazing-related problems due to high temperatures in double skin façadesPublication . Duarte, Rogério; Leandro, S. Oliveira; Teixeira, A. Rego; Bigode, C.The thermal behaviour of a double skin façade building is modelled using the DOE-2 building energy simulation program. Maximum temperatures of glazed components of the double skin façade are determined to assess the occurrence of glazing-related problems, such as reduced thermal and aesthetic performance, increased maintenance costs and even injury hazards. The importance of detailed thermal modelling of double skin façades and of its glazed componentes is concluded.
- Monitoring of a Double Skin Façade Building: Methodology and Office Thermal and Energy PerformancePublication . Marques da Silva, F.; Duarte, Rogério; Cardoso e Cunha, L.This paper concerns to the post-occupancy monitoring of a building sited in Lisbon with transparent double-skin façades. This is the first of an enlarged monitoring program covering other buildings and weather conditions, aiming to clarify under which climate and performing conditions this architectural solution is acceptable. Within this campaign an enlarged set of parameters was measured from external conditions to energy consumption and indoor comfort. The present paper describes the building, presents the monitoring methodology and analyses the thermal and energy performance of a specific office space.
- Energy Benchmarking of Double-Skin Façade BuildingsPublication . Duarte, Rogério; Matos, M. deThis paper describes ongoing energy benchmarking studies of double-skin façade buildings. Benchmarking methodology is discussed. Some preliminary results are presented.
- On the Typology, Costs, Energy Performance, Environmental Quality and Operational Characteristics of Double Skin Façades in European BuildingsPublication . Streicher, Wolfgang; Heimrath, Richard; Hengsberger, Herwig; Mach, Thomas; Waldnere, Reinhard; Flamantf, Gilles; Loncourg, Xavier; Guarracinoh, Gérard; Erhorni, Hans; Erhorn-Kluttigj, Heike; Santamourisk, Matheos; Faroul, Ifigenia; Zerefosm, S.; Assimakopoulosn, M.; Duarte, Rogério; Blomsterbergp, Åke; Sjöbergq, Lars; Blomquistr, ChristerThe project BESTFAÇADE, sponsored by the Energy Intelligent Europe programme of the European Union, and led by MCE-Anlagenbau, Austria, accumulated the state of the art of double skin façades (DSFs) in seven European countries (Austria, Belgium, France, Germany, Greece, Portugal and Sweden). Twenty-eight façades of different buildings in all partner countries of BESTFAÇADE have been analysed for the aspects, types of façade in different countries, DSFs in different climatic regions of Europe, existing simulations and measurements, thermal behaviour, indoor air quality, comfort, user acceptance, energy demand and consumptions, control strategies, integrated building technology, cost (investment, maintenance and operation), resource conservation, environmental impact, comparison to conventional glass façades (CGFs), integration of renewable energy sources into DSFs, as well as non-energy related issues, such as, acoustics, aesthetics, fire protection, moisture, corrosion, durability, maintenance and repair. Most of the buildings are office buildings, followed by schools and service buildings. Nearly all of the buildings have mechanical ventilation systems, and both heating and cooling are performed mostly by air heating/cooling systems. The types of façades are mainly multi-storey and corridor types; in Belgium juxtaposed modules are frequently used. The façade gaps are mostly naturally ventilated (except for Belgium, where the indoor air is led by mechanical ventilation via the gap to the centralized air handling unit). The shading is performed mainly with Venetian blinds located in the gap. Unfortunately data on energy demand and temperatures are infrequently measured and rarely available. The cost of DSFs is significantly higher than conventional façades.
- A comparison between energy performance of one DSF buildings studied sample and office buildings benchmarks in EuropePublication . Matos, M. de; Duarte, RogérioThis paper describes ongoing energy benchmarks studies of double-skin façade buildings. A comparison between energy performance of these actual buildings and European office buildings benchmarks is discussed. Some preliminary results are presented.
- Influence of virtual changes in buildingconfigurations of a real street canyon on thedispersion of PM10Publication . Garcia, João; Cerdeira, Rita; Tavares, Nelson; Coelho, Luis Manuel Rodrigues; Kumar, Prashant; Carvalho, M. G.Four geometrical configurations of a real street canyon in Barreirocity (Portugal) are considered to study their influence on the dis-persion of PM10. These configurations include actual architectural layout of the street (Option 1), and three virtual cases (Options1–3). Option 2 includes the modification of real geometry byincluding 4 m gaps between the buildings situated on the southern part of the street canyon. Option 3 considers 6 m gaps betweenbuildings as opposed to 4 m gaps in Option 2. Option 4 assumesthe same height for all buildings on the southern part of the street canyon, with no gaps between buildings. Computational fluid dynamics code (CFD), FLUENT, is used to simulate the detailed flow and turbulence characteristics in three-dimensional domain ofchosen street canyon, together with the PM10 dispersion for both the summer and winter seasons. The modelled PM10 concentra-tions were then compared with the measured data at seven differ-ent locations in the street canyon. Our results indicate up to 23%lower PM10concentrations at 1.5 m above the road level during the along-canyon wind direction due to the channelling of flow,compared with those observed during the cross-canyon wind direction. Detailed inspection of the results obtained from the Options 1–3 indicated that the spacing between the buildings tendto increase particle dilution during the cross-canyon winds resulting in up to 20, and 22% reduced concentrations for options 2,and 3 respectively, compared with the actual configuration (Option1). The largest improvement ( 7%) in the PM10concentrations wasgiven by Option 2, while other options showed modest changes.Possible reasons for these changes under varying meteorological conditions are explained in the context of changing building con-figurations and their implications in city planning.
- Studying street geometry influence in PM10 concentrationPublication . Garcia, João; Cerdeira, Rita; Tavares, Nelson; Coelho, Luis Manuel Rodrigues