Author: David L. Whitfield
Publisher:
ISBN:
Category :
Languages : en
Pages : 45
Book Description
Results are presented of sphere drag measurements made in the free-molecular and transitional flow regimes. The drag data were obtained using a drag balance and the free-flight technique. Conditions for which measurements were made are given. An analysis of the drag on a sphere in rarefied flow is also presented, and the results are compared with experimental data and other theories. The analytical results well predict the trend of the experimental data in the transition regime and remain valid at Knudsen numbers for which previous theories are not applicable. (Author).
Sphere Drag in the Free-molecular and Transitional Flow Regimes
Author: David L. Whitfield
Publisher:
ISBN:
Category :
Languages : en
Pages : 45
Book Description
Results are presented of sphere drag measurements made in the free-molecular and transitional flow regimes. The drag data were obtained using a drag balance and the free-flight technique. Conditions for which measurements were made are given. An analysis of the drag on a sphere in rarefied flow is also presented, and the results are compared with experimental data and other theories. The analytical results well predict the trend of the experimental data in the transition regime and remain valid at Knudsen numbers for which previous theories are not applicable. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 45
Book Description
Results are presented of sphere drag measurements made in the free-molecular and transitional flow regimes. The drag data were obtained using a drag balance and the free-flight technique. Conditions for which measurements were made are given. An analysis of the drag on a sphere in rarefied flow is also presented, and the results are compared with experimental data and other theories. The analytical results well predict the trend of the experimental data in the transition regime and remain valid at Knudsen numbers for which previous theories are not applicable. (Author).
Drag Coefficients of Spheres in Hypersonic Non-Continuum Flow
Author: John F. Wendt
Publisher:
ISBN:
Category :
Languages : en
Pages : 43
Book Description
A modulated force probe with a sensitivity in the microgram range was employed to measure the drag forces on spheres in the Mach 5 range with an R.M.S. error of + or - 1%. Flow properties in the free jet were used to calculate sphere drag coefficients. The resulting values cover the flow regimes from near-free-molecule to transitional. A correlation parameter - an 'effective' Knudsen number based on body-free stream molecular collisions - is shown to provide a reasonable correlation for a large variety of sphere drag measurements.
Publisher:
ISBN:
Category :
Languages : en
Pages : 43
Book Description
A modulated force probe with a sensitivity in the microgram range was employed to measure the drag forces on spheres in the Mach 5 range with an R.M.S. error of + or - 1%. Flow properties in the free jet were used to calculate sphere drag coefficients. The resulting values cover the flow regimes from near-free-molecule to transitional. A correlation parameter - an 'effective' Knudsen number based on body-free stream molecular collisions - is shown to provide a reasonable correlation for a large variety of sphere drag measurements.
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).
Measurement of Drag Forces in Low Density Flows
Author: J. J. Smolderen
Publisher:
ISBN:
Category : Drag (Aerodynamics)
Languages : en
Pages : 30
Book Description
A new technique to accurately measure low level forces and its application to the determination of drag coefficients in rarefied hypersonic flow are described. Preliminary results are presented for cylinders and spheres at M = 8 in the transitional and near-free-molecule flow regimes. (Author).
Publisher:
ISBN:
Category : Drag (Aerodynamics)
Languages : en
Pages : 30
Book Description
A new technique to accurately measure low level forces and its application to the determination of drag coefficients in rarefied hypersonic flow are described. Preliminary results are presented for cylinders and spheres at M = 8 in the transitional and near-free-molecule flow regimes. (Author).
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
A Study of Sphere Drag in the Transition from Continuum to Free Molecular Flow
Author: K. S. Hadjimichalis
Publisher:
ISBN:
Category :
Languages : en
Pages : 145
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 145
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
Proceedings of the Eighth Annual Thermal and Fluids Analysis Workshop: Spacecraft Analysis and Design
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 188
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 188
Book Description
Applied Mechanics Reviews
Author:
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 568
Book Description
Publisher:
ISBN:
Category : Mechanics, Applied
Languages : en
Pages : 568
Book Description
32nd Aerospace Sciences Meeting & Exhibit: 94-0569 - 94-0609
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 474
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 474
Book Description