Measurements of Atmospheric Turbulence Over a Wide Range of Wavelength for One Meteorological Condition

Measurements of Atmospheric Turbulence Over a Wide Range of Wavelength for One Meteorological Condition PDF Author: Harold L. Crane
Publisher:
ISBN:
Category : Atmospheric turbulence
Languages : en
Pages : 18

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Book Description
A method for obtaining a power spectrum of gust vertical velocity over a wide range of wavelength from simultaneous measurements made in flight has been devised and applied. This method has the advantage of not involvhg the use of airplane transfer functions. A gust vertical velocity spectrum was determined for one meteorological condition for wavelengths from 10 feet to 60,000 feet. The test was conducted at low altitude in clear- turbulence having a root-mean-square intensity of 5 feet per second. At the higher frequencies (shorterwavelengths), the power spectral density varied at a rate which was between the -5/3 power which has been predicted theoretically and the inverse square of the frequency. The spectrum which was obtained tended to flatten out for the longest test wavelengths.The break frequency which provides an indication of the scale of the turbulence occurred at a wavelength of approximately 6,000 feet. The results obtained indicate that the method of obtaining spectra used in this investigation is practicable.

Measurements of Atmospheric Turbulence Over a Wide Range of Wavelength for One Meteorological Condition

Measurements of Atmospheric Turbulence Over a Wide Range of Wavelength for One Meteorological Condition PDF Author: Harold L. Crane
Publisher:
ISBN:
Category : Atmospheric turbulence
Languages : en
Pages : 18

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Book Description
A method for obtaining a power spectrum of gust vertical velocity over a wide range of wavelength from simultaneous measurements made in flight has been devised and applied. This method has the advantage of not involvhg the use of airplane transfer functions. A gust vertical velocity spectrum was determined for one meteorological condition for wavelengths from 10 feet to 60,000 feet. The test was conducted at low altitude in clear- turbulence having a root-mean-square intensity of 5 feet per second. At the higher frequencies (shorterwavelengths), the power spectral density varied at a rate which was between the -5/3 power which has been predicted theoretically and the inverse square of the frequency. The spectrum which was obtained tended to flatten out for the longest test wavelengths.The break frequency which provides an indication of the scale of the turbulence occurred at a wavelength of approximately 6,000 feet. The results obtained indicate that the method of obtaining spectra used in this investigation is practicable.

Measurements of Atmospheric Turulence Over a Wide Range of Wavelength for One Meteorological Condition

Measurements of Atmospheric Turulence Over a Wide Range of Wavelength for One Meteorological Condition PDF Author: Harold L. Crane
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Technical Note - National Advisory Committee for Aeronautics

Technical Note - National Advisory Committee for Aeronautics PDF Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1076

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Technical Note

Technical Note PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 342

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Index of NACA Technical Publications

Index of NACA Technical Publications PDF Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 580

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Analysis and Comparison with Theory of Flow-field Measurements Near a Lifting Rotor in the Langley Full-scale Tunnel

Analysis and Comparison with Theory of Flow-field Measurements Near a Lifting Rotor in the Langley Full-scale Tunnel PDF Author: Harry H. Heyson
Publisher:
ISBN:
Category : Air flow
Languages : en
Pages : 696

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Book Description
Results of an investigation in the Langley full-scale tunnel of the induced flow near a lifting rotor are given. Measurements of stream angles and velocities were made in several transverse planes along and behind the rotor in four different conditions representative of the cruising and high-speed ranges of flight. These measurements indicate that available theory may be used to calculate with reasonable accuracy the induced flow over the forward three-quarters of the disk for these flight conditions provided that a realistic nonuniform rotor disk-load distribution is assumed. Rearward of the three-quarter-diameter point, calculations of the induced velocity are increasingly inaccurate due to the rolling up of the trailing-vortex system. Farther rearward, well behind the rotor, the flow may be represented more accurately by the flow behind a uniformly loaded wing.

NASA Technical Note

NASA Technical Note PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 408

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An Analog Study of an Airborne Automatic Landing-approach System

An Analog Study of an Airborne Automatic Landing-approach System PDF Author: James J. Adams
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 62

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NASA Technical Report

NASA Technical Report PDF Author:
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 72

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Research Abstracts and Reclassification Notice

Research Abstracts and Reclassification Notice PDF Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 508

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