Determination of Wind Shear and Turbulence Intensity According to Yak42-D “Roshydromet” Research Aircraft Data

2021 ◽  
Vol 46 (9) ◽  
pp. 640-649
Author(s):  
V. V. Volkov ◽  
M. A. Strunin ◽  
A. M. Strunin
Keyword(s):  
Turbulence Intensity ◽  
Wind Shear ◽  
Research Aircraft ◽  
Aircraft Data

DETERMINATION OF WIND SHEAR AND TURBULENCE INTENSITY ACCORDING TO YAK42-D “ROSHYDROMET” RESEARCH AIRCRAFT DATA

2021 ◽  
pp. 117-129
Author(s):  
V. V. VOLKOV ◽  
◽  
M. A. STRUNIN ◽  
A. M. STRUNIN ◽  
◽  
...  
Keyword(s):  
Boundary Layer ◽  
Wind Speed ◽  
Wind Shear ◽  
Vertical Shear ◽  
Horizontal Shear ◽  
S 100 ◽  
Research Aircraft ◽  
The Difference ◽  
Wind Shears ◽  
Aircraft Data

The results of the development and comparative analysis of methods for determining wind shear in the atmosphere (regression and difference ones) based on research aircraft data are presented. It is shown that shear calculation by the regression method gives the error of 0.002-0.006 (m/s)/km (depending on the length of the measurement sections) for horizontal shears and 0.04-0.12 (m/s)/100 m for vertical shears; the respective error of the difference method is 0.007 (m/s)/km and 0.07 (m/s)/100 m. Based on the Yak-42D “Roshydromet” research aircraft data, the values of shears of two horizontal components of wind speed in three directions (two horizontal and vertical) were calculated. According to the data of two research aircraft flights, the maximum values of the horizontal shear of wind speed components were reached above the boundary layer and were equal to 0.2 (m/s)/km, and the vertical shear was 1.2 (m/s)/100 m. The energy profiles of horizontal and vertical turbulent pulsations are constructed, it is shown that intense turbulence smooths wind shears in the convective atmospheric boundary layer.

scholarly journals Design and characterization of specMACS, a multipurpose hyperspectral cloud and sky imager

2016 ◽  
Vol 9 (5) ◽  
pp. 2015-2042 ◽  
Author(s):  
Florian Ewald ◽  
Tobias Kölling ◽  
Andreas Baumgartner ◽  
Tobias Zinner ◽  
Bernhard Mayer
Keyword(s):  
Software Design ◽  
Infrared Region ◽  
Central Wavelength ◽  
Laboratory Characterization ◽  
Research Aircraft ◽  
Sky Imager ◽  
Remote Sensing Techniques ◽  
Shortwave Infrared

Abstract. The new spectrometer of the Munich Aerosol Cloud Scanner (specMACS) is a multipurpose hyperspectral cloud and sky imager designated, but is not limited to investigations of cloud–aerosol interactions in Earth's atmosphere. With its high spectral and spatial resolution, the instrument is designed to measure solar radiation in the visible and shortwave infrared region that is reflected from, or transmitted through clouds and aerosol layers. It is based on two hyperspectral cameras that measure in the solar spectral range between 400 and 2500 nm with a spectral bandwidth between 2.5 and 12.0 nm. The instrument was operated in ground-based campaigns as well as aboard the German High Altitude LOng Range (HALO) research aircraft, e.g., during the ACRIDICON-CHUVA campaign in Brazil during summer 2014. This paper describes the specMACS instrument hardware and software design and characterizes the instrument performance. During the laboratory characterization of the instrument, the radiometric response as well as the spatial and spectral resolution was assessed. Since the instrument is primarily intended for retrievals of atmospheric quantities by inversion of radiative models using measured radiances, a focus is placed on the determination of its radiometric response. Radiometric characterization was possible for both spectrometers, with an absolute accuracy of 3 % at their respective central wavelength regions. First measurements are presented which demonstrate the wide applicability of the instrument. They show that key demands are met regarding the radiometric and spectral accuracy which is required for the intended remote sensing techniques.

scholarly journals Calibration of the passive cavity aerosol spectrometer probe for airborne determination of the size distribution

2013 ◽  
Vol 6 (3) ◽  
pp. 4123-4152 ◽  
Author(s):  
Y. Cai ◽  
J. R. Snider ◽  
P. Wechsler
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Scattered Light ◽  
Particle Diameter ◽  
Polystyrene Latex ◽  
Calibration Methods ◽  
Research Aircraft ◽  
Amplifier Gain ◽  
Gain Stage

Abstract. This work describes calibration methods for the particle sizing and particle concentration systems of the passive cavity aerosol spectrometer probe (PCASP). Laboratory calibrations conducted over six years, in support of the deployment of a PCASP on a cloud physics research aircraft, are analyzed. Instead of using the many calibration sizes recommended by the PCASP manufacturer, a relationship between particle diameter and scattered light intensity is established using three sizes of mobility-selected polystyrene latex particles, one for each amplifier gain stage. In addition, studies of two factors influencing the PCASP's determination of the particle size distribution – amplifier baseline and particle shape – are conducted. It is shown that the PCASP-derived size distribution is sensitive to adjustments of the sizing system's baseline voltage, and that for aggregate spheres, a PCASP-derived particle size and a sphere-equivalent particle size agree within uncertainty dictated by the PCASP's sizing resolution. Robust determination of aerosol concentration, and size distribution, also require calibration of the PCASP's aerosol flowrate sensor. Sensor calibrations, calibration drift, and the sensor's non-linear response are documented.

scholarly journals Research Aircraft and Wind Profiler Observations in Gastineau Channel during a Taku Wind Event*

2006 ◽  
Vol 21 (4) ◽  
pp. 489-501 ◽  
Author(s):  
Nicholas A. Bond ◽  
Carl F. Dierking ◽  
James D. Doyle
Keyword(s):  
Wind Shear ◽  
Vertical Wind Shear ◽  
Vertical Wind ◽  
Naval Research ◽  
Wind Profiler ◽  
Mean Flow ◽  
Gap Flow ◽  
Wind Event ◽  
Research Aircraft ◽  
Downslope Flow

Abstract The flow in Gastineau Channel near Juneau, Alaska, during the moderate Taku wind event of 18 October 2004 is examined using observations from the University of Wyoming’s King Air research aircraft, two wind profilers, and surface weather stations. These data sources reveal low-level winds directed down the central portion of Gastineau Channel, that is, gap flow. Farther down the channel, and above this gap flow, the winds were strongly cross channel in association with the downslope flow that characterizes Taku events. The transition region between these two flows included strong vertical wind shear and severe turbulence; measurements from the King Air indicate turbulent kinetic energy locally exceeding 50 m2 s−2. A high-resolution simulation of this case using the Naval Research Laboratory’s Coupled Ocean–Atmosphere Mesoscale Prediction System reproduced the observed character of the mean flow. This case illustrates the hazard to aviation posed by even a moderate Taku wind event and shows the value of a wind profiler for monitoring the vertical wind shear responsible for the hazard.

scholarly journals Inflight Engine Performance Evaluations

1976 ◽  
Author(s):  
W. E. Beck
Keyword(s):  
Engine Performance ◽  
Aircraft Design ◽  
Operating Regime ◽  
Performance Evaluations ◽  
Development Phase ◽  
Complex Task ◽  
Wind Tunnel Model ◽  
Tunnel Model ◽  
Aircraft Data

The measurement/determination of installed inflight engine performance on an aircraft is a complex task. To be successful requires that wind tunnel model and full-scale inflight test programs be fully planned early in the development phase of the aircraft design. In particular, methodology and instrumentation requirements must be coordinated in these programs. This paper discusses the requirements and methodology for inflight engine performance evaluations as applied to a subsonic ASW type aircraft. Data are presented which show that two independent methods of calculating steady-state engine net thrust levels agree to within ± 1.5 percent of each other over the full operating regime of the aircraft. Finally, comparisons of calculated performance with that predicted from the engine manufacturer’s cycle deck are presented.

scholarly journals The Influence of Tilt Angle on the Aerodynamic Performance of a Wind Turbine

2020 ◽  
Vol 10 (15) ◽  
pp. 5380
Author(s):  
Qiang Wang ◽  
Kangping Liao ◽  
Qingwei Ma
Keyword(s):  
Wind Turbine ◽  
Turbulence Intensity ◽  
Tilt Angle ◽  
Wind Shear ◽  
Cfd Simulation ◽  
Aerodynamic Performance ◽  
Tip Vortices ◽  
Sliding Mesh ◽  
Blade Section ◽  
Lift And Drag

Aerodynamic performance of a wind turbine at different tilt angles was studied based on the commercial CFD software STAR-CCM+. Tilt angles of 0, 4, 8 and 12° were investigated based on uniform wind speed and wind shear. In CFD simulation, the rotating motion of blade was based on a sliding mesh. The thrust, power, lift and drag of the blade section airfoil at different tilt angles have been widely investigated herein. Meanwhile, the tip vortices and velocity profiles at different tilt angles were physically observed. In addition, the influence of the wind shear exponents and the expected value of turbulence intensity on the aerodynamic performance of the wind turbine is also further discussed. The results indicate that the change in tilt angle changes the angle of attack of the airfoil section of the wind turbine blade, which affects the thrust and power of the wind turbine. The aerodynamic performance of the wind turbine is better when the tilt angle is about 4°. Wind shear will cause the thrust and power of the wind turbine to decrease, and the effect of the wind shear exponents on the aerodynamic performance of the wind turbine is significantly greater than the expected effect of the turbulence intensity. The main purpose of the paper was to study the effect of tilt angle on the aerodynamic performance of a fixed wind turbine.

Sign in / Sign up

Export Citation Format

Share Document