Author: John W. Boring
Publisher:
ISBN:
Category : Artificial satellites
Languages : en
Pages : 52
Book Description
The drag coefficients for the Echo 1 and Explorer 24 spherical surfaces in an O environment were experimentally determined over an energy range of 4 to 200 eV. The experiment was performed by generating a beam of atomic oxygen ions of the proper energy, neutralizing a portion of the beam, and then allowing only the neutral O particles to strike a very sensitive torsion balance. The momentum transferred to the surface was determined from the deflection of the torsion balance. At the lower energies, the more intense ion beam had to be used instead of the neutral beam. The drag coefficients are found to be slightly greater than 2 at energies corresponding to satellite velocities.
Drag Coefficients for Spheres in Free Molecular Flow in O at Satellite Velocities
Author: John W. Boring
Publisher:
ISBN:
Category : Artificial satellites
Languages : en
Pages : 52
Book Description
The drag coefficients for the Echo 1 and Explorer 24 spherical surfaces in an O environment were experimentally determined over an energy range of 4 to 200 eV. The experiment was performed by generating a beam of atomic oxygen ions of the proper energy, neutralizing a portion of the beam, and then allowing only the neutral O particles to strike a very sensitive torsion balance. The momentum transferred to the surface was determined from the deflection of the torsion balance. At the lower energies, the more intense ion beam had to be used instead of the neutral beam. The drag coefficients are found to be slightly greater than 2 at energies corresponding to satellite velocities.
Publisher:
ISBN:
Category : Artificial satellites
Languages : en
Pages : 52
Book Description
The drag coefficients for the Echo 1 and Explorer 24 spherical surfaces in an O environment were experimentally determined over an energy range of 4 to 200 eV. The experiment was performed by generating a beam of atomic oxygen ions of the proper energy, neutralizing a portion of the beam, and then allowing only the neutral O particles to strike a very sensitive torsion balance. The momentum transferred to the surface was determined from the deflection of the torsion balance. At the lower energies, the more intense ion beam had to be used instead of the neutral beam. The drag coefficients are found to be slightly greater than 2 at energies corresponding to satellite velocities.
Drag coefficients for spheres for free molecular flow in n2 at satellite velocities
Author: John Wayne Boring
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 8
Book Description
Drag Coefficients of Microscopic Spheres in Free-molecule Flow
Author: A. S. Hersh
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 44
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 44
Book Description
Drag Force on Objects in the Nearly Free Molecular Flow Regime as a Function of Speed Ratio
Author: Y. Y. Lin Wang
Publisher:
ISBN:
Category :
Languages : en
Pages : 100
Book Description
The drag coefficient of an object moving in a rarefied gas can be expanded in terms of the inverse Knudsen number. In the reported equation one term represents the drag coefficient in the free molecular flow limit. It is shown that a second coefficient is determined by a set of well defined collision integrals associated with sequences of successive collisions among two molecules and the object. These collision integrals are evaluated for a disc and a sphere assuming that the gas molecules are reflected diffusively by the object. The molecules are treated as hard spheres and the drag coefficient is studied as a function of the velocity of the object. (Modified author abstract).
Publisher:
ISBN:
Category :
Languages : en
Pages : 100
Book Description
The drag coefficient of an object moving in a rarefied gas can be expanded in terms of the inverse Knudsen number. In the reported equation one term represents the drag coefficient in the free molecular flow limit. It is shown that a second coefficient is determined by a set of well defined collision integrals associated with sequences of successive collisions among two molecules and the object. These collision integrals are evaluated for a disc and a sphere assuming that the gas molecules are reflected diffusively by the object. The molecules are treated as hard spheres and the drag coefficient is studied as a function of the velocity of the object. (Modified author abstract).
Drag Coefficients of Microscopic Spheres in Free-molecule Flow
Author: A. S. Hersh
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 44
Book Description
Publisher:
ISBN:
Category : Aerodynamics
Languages : en
Pages : 44
Book Description
Advances in Spacecraft Technologies
Author: Jason Hall
Publisher: BoD – Books on Demand
ISBN: 9533075511
Category : Technology & Engineering
Languages : en
Pages : 612
Book Description
The development and launch of the first artificial satellite Sputnik more than five decades ago propelled both the scientific and engineering communities to new heights as they worked together to develop novel solutions to the challenges of spacecraft system design. This symbiotic relationship has brought significant technological advances that have enabled the design of systems that can withstand the rigors of space while providing valuable space-based services. With its 26 chapters divided into three sections, this book brings together critical contributions from renowned international researchers to provide an outstanding survey of recent advances in spacecraft technologies. The first section includes nine chapters that focus on innovative hardware technologies while the next section is comprised of seven chapters that center on cutting-edge state estimation techniques. The final section contains eleven chapters that present a series of novel control methods for spacecraft orbit and attitude control.
Publisher: BoD – Books on Demand
ISBN: 9533075511
Category : Technology & Engineering
Languages : en
Pages : 612
Book Description
The development and launch of the first artificial satellite Sputnik more than five decades ago propelled both the scientific and engineering communities to new heights as they worked together to develop novel solutions to the challenges of spacecraft system design. This symbiotic relationship has brought significant technological advances that have enabled the design of systems that can withstand the rigors of space while providing valuable space-based services. With its 26 chapters divided into three sections, this book brings together critical contributions from renowned international researchers to provide an outstanding survey of recent advances in spacecraft technologies. The first section includes nine chapters that focus on innovative hardware technologies while the next section is comprised of seven chapters that center on cutting-edge state estimation techniques. The final section contains eleven chapters that present a series of novel control methods for spacecraft orbit and attitude control.
NASA Technical Note
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 444
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 444
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1150
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1150
Book Description
Free-Flight Measurements of Sphere Drag at Subsonic, Transonic, Supersonic, and Hypersonic Speeds for Continuum, Transition, and Near-Free- Molecular Flow Conditions
Author: A. B. Bailey
Publisher:
ISBN:
Category :
Languages : en
Pages : 97
Book Description
A comprehensive set of measurements was made in a ballistic range which permits the sphere drag coefficient to be derived with an uncertainty of approximately +2 or -2 percent in the flight regime 0.1
Publisher:
ISBN:
Category :
Languages : en
Pages : 97
Book Description
A comprehensive set of measurements was made in a ballistic range which permits the sphere drag coefficient to be derived with an uncertainty of approximately +2 or -2 percent in the flight regime 0.1
Sphere Drag in a Low Density Supersonic Flow
Author: Jerome Aroesty
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 318
Book Description
Sphere drag coefficients were measured in the Berkeley Low Density Wind Tunnel at Mach equals 2, 4, and 6, and free stream Reynolds numbers between 10 and 10,000 for both insulated and cold wall conditions. The measurements indicate that sphere drag in this regime is strongly dependent on the Reynolds number behind a normal shock wave, and only weakly dependent on Mach number. In addition, it was found that a decrease in wall temperature/stagnation temperature (T sub w/T sub o) from 1 to 0.26 was accompanied by a 5 - 10% decrease in the drag coefficient. A precision microbalance was used to obtain data for insulated spheres, and a moving model technique was used to obtain data for small spheres falling freely through a wind tunnel jet. These latter tests were performed using both cold and insulated models. The results on insulated spheres at M equal 2 and 4 were in good agreement with the measurements of other investigators. The results of the cold wall tests indicate that for Mach numbers greater than 5 in air, sphere drag coefficients are a function only of T sub w/T sub o and the post normal shock Reynolds number. (Author).
Publisher:
ISBN:
Category : Aerodynamics, Supersonic
Languages : en
Pages : 318
Book Description
Sphere drag coefficients were measured in the Berkeley Low Density Wind Tunnel at Mach equals 2, 4, and 6, and free stream Reynolds numbers between 10 and 10,000 for both insulated and cold wall conditions. The measurements indicate that sphere drag in this regime is strongly dependent on the Reynolds number behind a normal shock wave, and only weakly dependent on Mach number. In addition, it was found that a decrease in wall temperature/stagnation temperature (T sub w/T sub o) from 1 to 0.26 was accompanied by a 5 - 10% decrease in the drag coefficient. A precision microbalance was used to obtain data for insulated spheres, and a moving model technique was used to obtain data for small spheres falling freely through a wind tunnel jet. These latter tests were performed using both cold and insulated models. The results on insulated spheres at M equal 2 and 4 were in good agreement with the measurements of other investigators. The results of the cold wall tests indicate that for Mach numbers greater than 5 in air, sphere drag coefficients are a function only of T sub w/T sub o and the post normal shock Reynolds number. (Author).