Accession Number : ADA185877

Title :   Development of a Microburst Turbulence Model for the Joint Airport Weather Studies Wind Shear Data.

Descriptive Note : Technical rept.,

Corporate Author : FWG ASSOCIATES INC TULLAHOMA TN

Personal Author(s) : Chang, Ho-Pen ; Frost, Walter

PDF Url : ADA185877

Report Date : Mar 1987

Pagination or Media Count : 79

Abstract : A turbulence model is developed to supplement the microburst quasi-steady wind shear model established earlier from the JAWS Doppler radar data sets. The wind shear model is, in effect, a quasi-steady, spatially varying wind field. The spatial scale of the wind variation is on the order of 500-750 ft (150-200 m). Airborne sensor response (i.e., angle of attack, stall warning, pitot tubes, etc,), structural dynamics, pilot workload, and other such factors, however, respond to much higher frequency wind effects. To account for these effects, a 'first-cut' turbulence model based on Doppler radar second moment data is presented. Superimposing the turbulent fluctuation from this turbulence model on the quasi-steady JAWS wind field is believed to provide a more realistic simulation of the microburst flow for aviation application. The Doppler radar second moments of spectral width data from the June 30, July 14, and August 5, 1982, JAWS microburst measurements are analyzed in considerable detail. Microburst turbulence intensity is calculated by subtracting the spectral width broadenings due to wind shear, antenna motion, and precipitation fall speeds from the radar spectra width. (Author)

Descriptors :   *TURBULENCE, *WIND SHEAR, AERONAUTICS, AIRBORNE, ANGLE OF ATTACK, ANTENNAS, DETECTORS, DOPPLER RADAR, DYNAMICS, FLOW, FREQUENCY, INTENSITY, MEASUREMENT, MODELS, MOMENTS, MOTION, PILOTS, PITOT TUBES, RADAR, RESPONSE, SCALE, SIMULATION, SPATIAL DISTRIBUTION, SPECTRA, STALL WARNING INDICATORS, STRUCTURAL PROPERTIES, VARIATIONS, VELOCITY, WIDTH, WIND, WORKLOAD

Subject Categories : Meteorology

Distribution Statement : APPROVED FOR PUBLIC RELEASE