Author: I. Kusmarwanto
Publisher:
ISBN: 9780947767211
Category : Aerodynamics
Languages : en
Pages : 210
Book Description
Ground Effect on a Rotor Wake
Author: I. Kusmarwanto
Publisher:
ISBN: 9780947767211
Category : Aerodynamics
Languages : en
Pages : 210
Book Description
Publisher:
ISBN: 9780947767211
Category : Aerodynamics
Languages : en
Pages : 210
Book Description
The Long Time Structure of the Rotor Wake in Ground Effect
Author: Devi Prasad Pulla
Publisher:
ISBN:
Category :
Languages : en
Pages : 256
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 256
Book Description
Analytical Model of Rotor Wake Aerodynamics in Ground Effect
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 200
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 200
Book Description
Structure of the Rotor Wake in Ground Effect
Author: S. Bhattacharyya
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Ground Effect on a Rotor Wake
Author: E. A. Bound
Publisher:
ISBN: 9780902937932
Category : Helicopters
Languages : en
Pages : 29
Book Description
Publisher:
ISBN: 9780902937932
Category : Helicopters
Languages : en
Pages : 29
Book Description
Ground Effect for Lifting Rotors in Forward Flight
Author: Harry H. Heyson
Publisher:
ISBN:
Category : Ground-cushion phenomenon
Languages : en
Pages : 18
Book Description
Publisher:
ISBN:
Category : Ground-cushion phenomenon
Languages : en
Pages : 18
Book Description
Wakes of Lifting Propellers (rotors) in Ground Effect
Author: F. A. DuWaldt
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 110
Book Description
The report presents the development of a wake model for a lifting propeller (rotor) in ground effect and the computational procedure used to determine the spacial distribution of wake vorticity and the induced velocity field accompanying that vorticity distribution. Sample calculations for a two-bladed rotor were carried out on an IBM 7044 computer. Locations of wake vortical elements and the associated induced velocities at selected field points are presented for advance ratios of 0, 0.02, 0.05, and 0.10 for an H/R (ratio of rotor height above ground to rotor radius) of 1.0. Also, a few results for a hovering case with H/R = 0.5 are presented. A calculated root-mean-square velocity map is compared with measured hovering data (time averaged) and good agreement is obtained in the outer half of the slipstream. The implications of computed results with respect to the flow field at a horizontal stabilizer or tail rotor are noted as examples of the use of the model. The wake vortex model used for these calculations is a distorted continuous helix emanating from each blade tip. (Author).
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 110
Book Description
The report presents the development of a wake model for a lifting propeller (rotor) in ground effect and the computational procedure used to determine the spacial distribution of wake vorticity and the induced velocity field accompanying that vorticity distribution. Sample calculations for a two-bladed rotor were carried out on an IBM 7044 computer. Locations of wake vortical elements and the associated induced velocities at selected field points are presented for advance ratios of 0, 0.02, 0.05, and 0.10 for an H/R (ratio of rotor height above ground to rotor radius) of 1.0. Also, a few results for a hovering case with H/R = 0.5 are presented. A calculated root-mean-square velocity map is compared with measured hovering data (time averaged) and good agreement is obtained in the outer half of the slipstream. The implications of computed results with respect to the flow field at a horizontal stabilizer or tail rotor are noted as examples of the use of the model. The wake vortex model used for these calculations is a distorted continuous helix emanating from each blade tip. (Author).
The Rotor Wake in Ground Effect and Its Investigation in a Wind Tunnel
Author: Nita Darshini Nathan
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 265
Book Description
Publisher:
ISBN:
Category : Rotors (Helicopters)
Languages : en
Pages : 265
Book Description
Rotor Aerodynamics in Ground Effect at Low Advance Ratios
Author: H. C Curtiss (Jr)
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
The results of an experimental study of the aerodynamic characteristics of a helicopter rotor operating in ground effect at low advance ratios are presented. Flow visualization studies were conducted along with measurement of the forces and moments acting on the rotor as a function of advance ratio, height above ground and collective pitch. Steady state experiments as well as non-steady experiments involving translational acceleration were conducted. Three distinct flow regimes were noted from the flow visualization studies. At the low end of the advance ratio range a recirculating flow was present, at intermediate advance ratios a horseshoe shaped vorted formed under the rotor, and at the high end of the advance ratio range studied, the rotor wake flows entirely downstream. At test conditions were the recirculating flow or ground vortex is present there are marked departures from classical ground effect theory. Translational acceleration was found to have a significant effect on the rotor forces and moments indicating that some appreciable time is required for the establishment of the ground effect flow field when a recirculating flow or ground vortex exists in the steady state. The results indicate that magnitude of the ground effects experienced by a helicopter are sensitive to the flight path of the helicopter. (Author).
Publisher:
ISBN:
Category :
Languages : en
Pages : 11
Book Description
The results of an experimental study of the aerodynamic characteristics of a helicopter rotor operating in ground effect at low advance ratios are presented. Flow visualization studies were conducted along with measurement of the forces and moments acting on the rotor as a function of advance ratio, height above ground and collective pitch. Steady state experiments as well as non-steady experiments involving translational acceleration were conducted. Three distinct flow regimes were noted from the flow visualization studies. At the low end of the advance ratio range a recirculating flow was present, at intermediate advance ratios a horseshoe shaped vorted formed under the rotor, and at the high end of the advance ratio range studied, the rotor wake flows entirely downstream. At test conditions were the recirculating flow or ground vortex is present there are marked departures from classical ground effect theory. Translational acceleration was found to have a significant effect on the rotor forces and moments indicating that some appreciable time is required for the establishment of the ground effect flow field when a recirculating flow or ground vortex exists in the steady state. The results indicate that magnitude of the ground effects experienced by a helicopter are sensitive to the flight path of the helicopter. (Author).
Effect of Ground And/or Ceiling Planes on Thrust of Rotors in Hover
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 46
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 46
Book Description