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Abstract Energy conservation, pollution prevention, resource efficiency, systems integration and life cycle costing are very important terms for sustainable construction. The purpose of this work is to ensure a power supply for the north of the Solar Energy Institute building environment lamps by using wind power to comply with the green building approach. Beside this, the study is to present an energy analysis of the 1.5 kW small wind turbine system (SWTS) with a hub height of 12 m above ground level with a 3 m rotor diameter in Turkey. The SWTS was installed at the Solar Energy Institute of Ege University (latitude 38.24 N, longitude 27.50 E), Izmir, Turkey. NACA 63-622 profile type (National Advisory Committee for Aeronautics) blades of epoxy carbon fiber reinforced plastics were used. The system was commissioned in September 2002, and performance tests have been conducted since then. The performance analysis of the SWTS is quantified and illustrated in the tables, particularly for a reference temperature of 25 °C, 30th of October 2003 till 5th of November 2003 for comparison purposes. Test results show that when the average wind speed is 7.5 m/s, 616 W and 76 Hz electricity is produced by the alternator.

Abstract Energy conservation, pollution prevention, resource efficiency, systems integration and life cycle costing are very important terms for sustainable construction. The purpose of this work is to ensure a power supply for the north of the Solar Energy Institute building environment lamps by using wind power to comply with the green building approach. Beside this, the study is to present an energy analysis of the 1.5 kW small wind turbine system (SWTS) with a hub height of 12 m above ground level with a 3 m rotor diameter in Turkey. The SWTS was installed at the Solar Energy Institute of Ege University (latitude 38.24 N, longitude 27.50 E), Izmir, Turkey. NACA 63-622 profile type (National Advisory Committee for Aeronautics) blades of epoxy carbon fiber reinforced plastics were used. The system was commissioned in September 2002, and performance tests have been conducted since then. The performance analysis of the SWTS is quantified and illustrated in the tables, particularly for a reference temperature of 25 °C, 30th of October 2003 till 5th of November 2003 for comparison purposes. Test results show that when the average wind speed is 7.5 m/s, 616 W and 76 Hz electricity is produced by the alternator.

A thermoelectric distillation system has recently been demonstrated to have a great potential of improving the efficiency of distillation processes due to the use of waste heat from the hot side of thermoelectric module to assist evaporation while the cold side for condensation. This work investigates the key factors that affect the water production in a thermoelectric distillation system. An experimental investigation was performed to investigate the influence of evaporation temperature, vapour volume, Peltier current and input power on the water production rate. The results of the experiment show that an increase in the sample water temperature from 30 °C to 60 °C led to an increase in total water production by 47%. In addition, an increase in total water production by 58% was obtained by reducing the vapour volume from 600 cm3 to 400 cm3 during a 3-h operation. The maximum water production rate is achieved by appropriate selection and control of the Peltier current to the thermoelectric device based on the operating condition of the distillation system.

A thermoelectric distillation system has recently been demonstrated to have a great potential of improving the efficiency of distillation processes due to the use of waste heat from the hot side of thermoelectric module to assist evaporation while the cold side for condensation. This work investigates the key factors that affect the water production in a thermoelectric distillation system. An experimental investigation was performed to investigate the influence of evaporation temperature, vapour volume, Peltier current and input power on the water production rate. The results of the experiment show that an increase in the sample water temperature from 30 °C to 60 °C led to an increase in total water production by 47%. In addition, an increase in total water production by 58% was obtained by reducing the vapour volume from 600 cm3 to 400 cm3 during a 3-h operation. The maximum water production rate is achieved by appropriate selection and control of the Peltier current to the thermoelectric device based on the operating condition of the distillation system.

Abstract Increased scrutiny on aviation’s environmental footprint has precipitated a dramatic increase in gas turbine technology development, with a focus on engine performance improvements and the reduction of noise and emissions. In a somewhat limited approach, these studies are often performed at the component level and at a single engine operating condition. In order to achieve future fuel consumption, noise, and emissions targets, it will be essential for designers to optimize the overall propulsive system across the entire trajectory. Accurate engine models will be needed to quantify the overall system performance and select the optimal components and the aircraft mission, highlighting the interconnection between optimization and engine modeling. In this paper, an engine modeling approach is described that provides a framework for analysis of the impact of component changes on the overall system for an entire trajectory. The engine model is built using a modeling environment developed by NASA called Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS). The modeling environment allows for transient updates to the boundary conditions, similar to what an engine would experience during operation. The emphasis on trajectory-driven design led to the development of a new blade tip optimization approach that improved turbine efficiency across a range of tip clearances rather than at a single clearance. The robust blade tip design approach used a multi-objective optimization with a differential evolution strategy and Computational Fluid Dynamics software to solve Reynolds-Averaged Navier-Stokes equations at three tip clearances. The optimization objectives were to increase the average and decrease the standard deviations of the stage efficiency for the three clearances. This approach demonstrated efficiency improvements as large as 0.50% with variations of standard deviations near zero. The robust blade tip optimization approach is discussed in detail, as well as a brief description of the physical mechanisms responsible for the performance improvement. Finally, in a demonstration of capability and applicability, turbine-specific updates are made to the baseline engine model. The updates include heat transfer and structural modules that are used to predict the turbine blade running tip clearance, which changes during the trajectory from 1.1% to 1.6% of span. Brief discussions of each module are included as well as a description of the turbine performance assessment. The impact of the blade tip clearance on the turbine efficiency across the trajectory is reported for three blade tip geometries: a baseline squealer design, a single point optimization design, and the robust blade tip optimization design. The results demonstrate the importance of trajectory-influenced design at both the component and engine level.

Abstract Increased scrutiny on aviation’s environmental footprint has precipitated a dramatic increase in gas turbine technology development, with a focus on engine performance improvements and the reduction of noise and emissions. In a somewhat limited approach, these studies are often performed at the component level and at a single engine operating condition. In order to achieve future fuel consumption, noise, and emissions targets, it will be essential for designers to optimize the overall propulsive system across the entire trajectory. Accurate engine models will be needed to quantify the overall system performance and select the optimal components and the aircraft mission, highlighting the interconnection between optimization and engine modeling. In this paper, an engine modeling approach is described that provides a framework for analysis of the impact of component changes on the overall system for an entire trajectory. The engine model is built using a modeling environment developed by NASA called Toolbox for the Modeling and Analysis of Thermodynamic Systems (T-MATS). The modeling environment allows for transient updates to the boundary conditions, similar to what an engine would experience during operation. The emphasis on trajectory-driven design led to the development of a new blade tip optimization approach that improved turbine efficiency across a range of tip clearances rather than at a single clearance. The robust blade tip design approach used a multi-objective optimization with a differential evolution strategy and Computational Fluid Dynamics software to solve Reynolds-Averaged Navier-Stokes equations at three tip clearances. The optimization objectives were to increase the average and decrease the standard deviations of the stage efficiency for the three clearances. This approach demonstrated efficiency improvements as large as 0.50% with variations of standard deviations near zero. The robust blade tip optimization approach is discussed in detail, as well as a brief description of the physical mechanisms responsible for the performance improvement. Finally, in a demonstration of capability and applicability, turbine-specific updates are made to the baseline engine model. The updates include heat transfer and structural modules that are used to predict the turbine blade running tip clearance, which changes during the trajectory from 1.1% to 1.6% of span. Brief discussions of each module are included as well as a description of the turbine performance assessment. The impact of the blade tip clearance on the turbine efficiency across the trajectory is reported for three blade tip geometries: a baseline squealer design, a single point optimization design, and the robust blade tip optimization design. The results demonstrate the importance of trajectory-influenced design at both the component and engine level.

Abstract A novel wind energy harvester is proposed and studied in this paper. The system contains a vibro-impact (VI) dielectric elastomer generator (DEG) that can convert vibrational energy into electrical one through the impacts of a rigid ball inside. The VI DEG is embedded into a cuboid bluff body connecting to a galloping-based system. Thus, wind energy is converted to the vibrations of the bluff body, which are further harvested by the DEG. The dynamic and electrical behaviors of the proposed system under wind environments are analyzed theoretically, whereas some key parameters of the system are identified experimentally, including a wind tunnel test for the bluff body and material tests for the dielectric elastomer membrane. The dynamic and electrical outputs of the system under different wind speeds are studied through numerical simulations. The influences of the wind speed and some system parameters on the system energy harvesting (EH) performance are further discussed. Thus, the priority of the proposed system in wind EH is presented and some effective solutions to design the system and improve the system EH performance are proposed.