37,286 research outputs found
CFD modelling of double-skin facades with venetian blinds
This paper describes CFD modelling of Double Skin Façades (DSF) with venetian blinds inside the façade cavity. The 2-D modelling work investigates the coupled convective, conductive and radiative heat transfer through the DSF system. The angles of the venetian blind can be adjusted and a series of angles (0, 30, 45, 60 and 80 degrees) has been modelled. The modelling results are compared with the
measurements from a section of façade tested within a solar simulator and with predictions from a component based nodal model. Agreement between the three methods is generally good. Discrepancies in the results are generally caused by the simplification of the CFD model resulting less turbulence mixing within the façade cavity. The CFD simulation output suggests that the presence of the venetian blinds has led up to 35 percent enhancement in natural ventilation flow for the façade cavity and 75 percent reduction in heat loads for the internal environment. It was also found that little changes of the convective heat transfer coefficients on the glazing surfaces have been caused by the venetian blinds with different angles
Implementation of the FAA research and development electromagnetic database
The Idaho National Engineering Laboratory (INEL) has been assisting the FAA in developing a database of information about lightning. The FAA Research and Development Electromagnetic Database (FRED) will ultimately contain data from a variety of airborne and ground-based lightning research projects. An outline of the data currently available in FRED is presented. The data sources which the FAA intends to incorporate into FRED are listed. In addition, it describes how the researchers may access and use the FRED menu system
Preliminary Abundance Analysis of Galactic Bulge Main Sequence, Subgiant, and Giant Branch Stars Observed During Microlensing with Keck/HIRES
We present an abundance analysis of six main sequence turnoff, subgiant, and
giant branch stars toward the Galactic bulge that were observed with Keck/HIRES
during microlensing events. This is an early look at the first detailed
chemical analysis of main sequence stars in the Galactic bulge. Lensing events
allow the effective aperture of Keck to be increased beyond its current
dimensions; although, some events still stretched its spectroscopic
capabilities. Future large telescopes with high resolution and high throughput
spectrometers will allow the study of abundances in distant stellar populations
and in less evolved stars with greater ease.Comment: 8 pages including 2 figures. To appear in SPIE proceedings on
Astronomical Telescopes and Instrumentation. Uses spie.cl
Streamlining the walls of an empty two-dimensional flexible-walled test section
The techniques used to find aerodynamically straight wall contours in a test section of a transonic wind tunnel are discussed. The walls were defined as aerodynamically straight up to Mach 0.9
Test Results of the Modified Space Shuttle Main Engine at the Marshall Space Flight Center Technology Test Bed Facility
A modified space shuttle main engine (SSME), which primarily includes an enlarged throat main combustion chamber with the acoustic cavities removed and a main injector with the stability control baffles removed, was tested. This one-of-a-kind engine's design changes are being evaluated for potential incorporation in the shuttle flight program in the mid-1990's. Engine testing was initiated on September 15, 1988 and has accumulated 1,915 seconds and 19 starts. Testing is being conducted to characterize the engine system performance, combustion stability with the baffle-less injector, and both low pressure oxidizer turbopump (LPOTP) and high pressure oxidizer turbopump (HPOTP) for suction performance. These test results are summarized and compared with the SSME flight configuration data base. Testing of this new generation SSME is the first product from the technology test bed (TTB). Figure test plans for the TTB include the highly instrumented flight configuration SSME and advanced liquid propulsion technology items
Population, Greenspace, and Development:Conversion Patterns in the Great Lakes Region
In this brief, authors Mark Ducey, Kenneth Johnson, Ethan Belair, and Barbara Cook combine demographic, land-cover, and other spatial data to estimate the incidence and extent of conversion from greenspace (forestland, shrublands, and grasslands) to development in the Great Lakes states. They report that greenspace conversions to developed land are most common in areas where greenspace is already limited. Population density strongly influences the conversion of greenspace to development. Conversions are most likely to occur on the urban periphery and in high-amenity rural areas. This research contributes to a better understanding of the linkages between demographic and land-cover change and provides facts that can inform policy aimed at balancing development and greenspace conservation
Depletion effects and loop formation in self-avoiding polymers
Langevin dynamics is employed to study the looping kinetics of self-avoiding
polymers both in ideal and crowded solutions. A rich kinetics results from the
competition of two crowding-induced effects: the depletion attraction and the
enhanced viscous friction. For short chains, the enhanced friction slows down
looping, while, for longer chains, the depletion attraction renders it more
frequent and persistent. We discuss the possible relevance of the findings for
chromatin looping in living cells.Comment: 4 pages, 3 figure
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