Author: Harold L. Crane
Publisher:
ISBN:
Category : Atmospheric turbulence
Languages : en
Pages : 18
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
Author: Harold L. Crane
Publisher:
ISBN:
Category : Atmospheric turbulence
Languages : en
Pages : 18
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.
Publisher:
ISBN:
Category : Atmospheric turbulence
Languages : en
Pages : 18
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
Author: Harold L. Crane
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Technical Note - National Advisory Committee for Aeronautics
Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1076
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1076
Book Description
Technical Note
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 342
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 342
Book Description
Index of NACA Technical Publications
Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 580
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 580
Book Description
Analysis and Comparison with Theory of Flow-field Measurements Near a Lifting Rotor in the Langley Full-scale Tunnel
Author: Harry H. Heyson
Publisher:
ISBN:
Category : Air flow
Languages : en
Pages : 696
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.
Publisher:
ISBN:
Category : Air flow
Languages : en
Pages : 696
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
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 408
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 408
Book Description
An Analog Study of an Airborne Automatic Landing-approach System
Author: James J. Adams
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 62
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 62
Book Description
NASA Technical Report
Author:
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 72
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 72
Book Description
Research Abstracts and Reclassification Notice
Author: United States. National Advisory Committee for Aeronautics
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 508
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 508
Book Description