Vol. 23 No. 2 (2008)

Modification of the conventional cycle in a geothermaL power plant is an alternative way that can be conducted in efficient conversion of thermal energy to be electric energy. Combination of Brayton cycle with fossil fuel energy sources and Rankine cycle utilizing geothermal energy is interest of this study. Kamojang Geothermal power plant is chosen as an object of casestudy. A software was developed to accurately evaluate the thermodynamic cycle with any modification. The software is supported by thermodynamic properties database directly derived from equations of state. Hybrid cycle…

Hydrocarbons (HC) are considered as the alterative substitutes of CFC and HCFC refrigerants. Using it as new refrigerants needs a complete knowledge of its characteristics. One of them is the boiling heat transfer coefficient. Series of experiments were carried out to investigate this characteristics. Experiments had been carried out with R-12 (CFC) and R-22 (HCFC) and their substitutes, HC-12 and HC-22. Tested refrigerant was conditiond at a saturated state and an electric heater immersed in the refrigerant pool of liquid was used as the boiling surface. Boiling heat transfer coefficient is…

The study was performed to acquire information on the qualitative flow condition and dynamical blockage effect on wing-body fairing configuration. The study was used to computational fluid dynamics to provide the pathlines patters and the total static pressure distribution in the vicinity junction region. Results of study in the research indicated that flow pattern influences by variation of angle of attack. As increasing of angle of attct so that the saddle point position move in to pressure side and away from wing surface. Meanwhile, separation line or imprint horseshoe vortex due to…

Nowadays, Micro Air Vehicle (MAV) is mostly developed for surveillance purpose, either for military or civilian. In this article, a design and building of a MAV will be presented. A tailless configuration was chosen. The design and build process started with a study of several design parameters of existing MAVs. Then, it is followed by initial sizing, detail design and production of the MAV. In general, the designed MAV could meet the design requirements and objectives stated. Some preliminary tests had shown that the basic flying characteristics was sufficiently good, although further…

In 2000, the TRIGA 2000 reactor in Bandung completed a commissioning program and received an operating license at 2000 kW. The Indonesia regulatory body (BAPETEN) issued a 15-year license, to operate the reactor at 2000 kW. During the commissioning tests, bubbling at the reactor core was observed and considered acceptable by General Atomic experts. The sub-cooled boiling observed during the commissiong tests confirmed the predictions of the thermal hydraulics calculations performed by General Atomics and presented in the safety analysis report. In 2004 the operating staff of the Bandung TRIGA…