ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • MECHANICAL ENGINEERING  (5)
  • ASTRONOMY  (1)
  • Human thermal comfort  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    International journal of biometeorology 34 (1990), S. 69-75 
    ISSN: 1432-1254
    Keywords: Human thermal comfort ; Radiation (absorbed) ; Outdool microclimates ; Human energy budget ; Microclimate simulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geography , Physics
    Notes: Abstract Research was conducted into the estimation of radiation absorbed by a vertical cylinder in complex outdoor environments under clear sky conditions. Two methods of estimation were employed: a cylindrical radiation thermometer (CRT) and model developed by Brown and Gillespie (1986), and the weather station model. The CRT produced an integrated temperature reading from which the radiant environment could be estimated successfully given simultaneous measurements of air temperature and wind speed. The CRT estimates compared to the measured radiation gave a correlation coefficient of 0.9499, SE=19.8 W/m2, α=99.9%. The physically-based equations (weather station model)require the inputs of data from a near by weather station and site characteristics to estimate radiation absorbed by a vertical cylinder. The correlation coefficient for the weather station model is 0.9529, SE=16.8 W/m2, α=99.9%. This model estimates short wave and long wave radiation separately; hence, this allowed further comparison to measured values. The short wave radiation was very successfully estimated:R=0.9865, SE=10.0 W/m2, α=99.9%. The long wave radiation estimates were also successful:R=0.8654, SE=15.7 W/m2, and α=99.9%. Though the correlation coefficient and standard error may suggest inaccuracy to the micrometeorologist, these estimation techniques would be extremely useful as predictors of human thermal comfort which is not a precise measure buut defined by a range. The reported methods require little specialized knowledge of micrometeorology and are vehicles for the designers of outdoor spaces to measure accurately the inherent radiant environment of outdoor spaces and provide a measurement technique to simulate or model the effect of various landscape elements on planned environments.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2006-02-14
    Description: Some 34 radio observatories in 18 countries are participating in the Radio Science Net of the International Halley Watch. Approximately 100 radio astronomers are contributing to this effort, which has included observations of comets P/Crommelin and P/Giacobini-Zinner as well as P/Halley. It is clear that the record of data for the 18 cm OH ground state lambda doublet, which provides fundamental information on the gas production rate, kinematics, and potentially the magnetic field in the coma, will be vastly more complete and of higher accuracy than has even been obtained on any previous comet. The coverage by a number of radio observatories will enable short period variations to be studied and correlated with simultaneous data obtained at other wavelengths. Likewise, the first definitive detection of the important parent molecule hydrogen cyanide in a comet was obtained and is being studied by groups in the United States, Sweden, and France. The first detection of the comet with the Very Large Array telescope operated by NRAO was achieved and has produced exciting results for the distribution of emission at high angular resolution from the OH radical. At this writing data are still being obtained and being processed, and there are still strong indications that exciting information will be obtained from radar studies of P/Halley and from searches for additional parent molecules.
    Keywords: ASTRONOMY
    Type: NASA, Washington Reports of Planetary Astronomy, 1985; p 177-178
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2013-08-31
    Description: Anti-swirl vanes are used by some manufacturers to delay the full development of half speed circulation in annular clearance spaces. The objective is to reduce the aerodynamic cross-coupling in the forward direction. The novel feature of a jet damper is a number of tangential nozzles discharging against the rotor surface speed. Some preliminary results on a 33.9 Kg rotor demonstrate that significant reductions in amplitude are obtained at the synchronous critical speeds.
    Keywords: MECHANICAL ENGINEERING
    Type: NASA. Lewis Research Center Rotordynamic Instability Problems in High-Performance Turbomachinery, 1986; p 325-347
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2016-06-07
    Description: The lateral forces induced by flow through model labyrinth glands were investigated. Circumferential pressure distributions, lateral forces and stiffness coefficients data obtained are discussed. The force system is represented as a negative spring and a tangential force orthogonal to eccentricity. The magnitude of these forces are dependent on eccentricity, entry swirl, rotor peripheral velocity and seal size. A pressure equalization chamber at midgland tests should in significantly reduced forces and stiffness coefficients.
    Keywords: MECHANICAL ENGINEERING
    Type: NASA. Lewis Research Center Rotordynamic Instability Problems in High-Performance Turbomachinery; p 187-210
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2013-08-31
    Description: This paper describes additional results from a continuing research program which aims to identify the dynamics of long annular seals in centrifugal pumps. A seal test rig designed at Heriot-Watt University and commissioned at Weir Pumps Research Laboratory in Alloa permits the identification of mass, stiffness, and damping coefficients using a least-squares technique based on the singular value decomposition method. The analysis is carried out in the time domain using a multi-fiequency forcing function. The experimental method relies on the forced excitation of a flexibly supported stator by two hydraulic shakers. Running through the stator embodying two symmetrical balance drum seals is a rigid rotor supported in rolling element bearings. The only physical connection between shaft and stator is the pair of annular gaps filled with pressurized water discharged axially. The experimental coefficients obtained from the tests are compared with theoretical values.
    Keywords: MECHANICAL ENGINEERING
    Type: NASA. Lewis Research Center, Rotordynamic Instability Problems in High-Performance Turbomachinery, 1993; p 149-165
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2016-06-07
    Description: A symmetric 3 mass rotor supported on hydrodynamic bearings is described. An approximate method of representing finite bearings is used to calculate bearing forces. As the method sums forces from a number of independent circular lobes lemon 3 and 4 lobe bearings are taken into account. The calculations are based on an axial groove bearing. Linear analysis precedes nonlinear simulation of some unstable conditions. The demonstration of small limit cycles suggests that necessarily flexible rotors e.g., helicopter tail rotors, may be practical without either tilt pad bearings or external dampers.
    Keywords: MECHANICAL ENGINEERING
    Type: NASA. Lewis Res. Center Rotordyn. Instability Probl. in High-Performance Turbomachinery; p 331-343
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2016-06-07
    Description: A research program to isolate and study leakage flow through labyrinth glands was initiated. Circumferential pressure distributions were measured in the labyrinth glands with geometry appropriate to the high pressure labyrinths in large steam turbines. Knowledge of this pressure distribution is essential as it is this unequal pressure field that results in the destabilizing force. Parameters that are likely to affect the pressure distributions are incorporated into the test rig. Some preliminary pressure profiles are presented.
    Keywords: MECHANICAL ENGINEERING
    Type: NASA. Lewis Research Center Rotordyn. Instability Probl. in High-Performance; p 223-241
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...