Aerodynamic Performance of a Helicopter Rotor Hovering in Close Proximity to the Obstacles with Penetration Boundary Condition

2016 ◽  
Vol 64 (1) ◽  
pp. 65-70
Author(s):  
Naohiro IBOSHI ◽  
Noriaki ITOGA ◽  
Yasuhide YAMANAKA ◽  
Abdul KADIR, ◽  
Yuzaburou HAYASHI ◽  
...  
Keyword(s):  
Boundary Condition ◽  
Aerodynamic Performance ◽  
Helicopter Rotor ◽  
Close Proximity

scholarly journals Numerical Analysis of Helicopter Rotor Hovering in Close Proximity to the Ground with a Wall

2010 ◽  
Vol 58 (680) ◽  
pp. 269-276 ◽  
Author(s):  
Noriaki ITOGA ◽  
Naohiro IBOSHI ◽  
Mitsumasa HORIMOTO ◽  
Shigeru SAITO ◽  
Yasutada TANABE
Keyword(s):  
Numerical Analysis ◽  
Helicopter Rotor ◽  
Close Proximity

scholarly journals Experimental study of a helicopter rotor model in hover

2018 ◽  
Vol 234 ◽  
pp. 01002 ◽  
Author(s):  
Filip Panayotov ◽  
Ivan Dobrev ◽  
Fawaz Massouh ◽  
Michael Todorov
Keyword(s):  
Experimental Study ◽  
Reynolds Numbers ◽  
Aerodynamic Performance ◽  
Test Stand ◽  
Helicopter Rotor ◽  
Helicopter Rotors ◽  
Aerodynamic Efficiency ◽  
Model Helicopter ◽  
Bladed Rotor ◽  
Thrust And Torque

This paper presents the results from an experimental study of the aerodynamic performance and efficiency of a model helicopter rotor in steady hover at Reynolds numbers below 70000. Results are shown for a two-, three- and four-bladed rotor configuration for various pitch angles and speeds of rotation. The influence of the rotor solidity on the aerodynamic efficiency in terms of the Figure of Merit is highlighted. The profile drag component is evaluated as a function of the Reynolds number. The internal friction losses of the test stand are estimated and taken into account in all measurements. A brief description of the designed test stand is provided. The experimental setup allows for the measurement of thrust and torque of helicopter rotors with diameters of up to 1 meter, for pitch angles varying from -12° to +24° and for rotational speeds of up to 3000 RPM. Conclusions are drawn about the aerodynamic performance and efficiency of the studied rotor configurations. This experimental study provided a significant database, which will serve for validation purposes.

scholarly journals Aerodynamic Performance of a Rotor Hovering in Close Proximity to Confined Area Ground

2010 ◽  
Vol 58 (682) ◽  
pp. 316-322 ◽  
Author(s):  
Naohiro IBOSHI ◽  
Noriaki ITOGA ◽  
Hiroyuki USUTA ◽  
Yuusuke KONAKAWA
Keyword(s):  
Aerodynamic Performance ◽  
Close Proximity

Passive flow control application for rotorcraft in transonic conditions

2018 ◽  
Vol 28 (5) ◽  
pp. 1080-1095 ◽  
Author(s):  
Fernando Tejero Embuena ◽  
Piotr Doerffer ◽  
Pawel Flaszynski ◽  
Oskar Szulc
Keyword(s):  
Flow Control ◽  
Vortex Formation ◽  
Strong Shock ◽  
Aerodynamic Performance ◽  
Rotor Blades ◽  
Vortex Generators ◽  
Helicopter Rotor ◽  
Streamwise Vortices ◽  
Content Type ◽  
Helicopter Rotor Blades

Purpose Helicopter rotor blades are usually aerodynamically limited by the severe conditions present in every revolution: strong shock wave boundary layer interaction on the advancing side and dynamic stall on the retreating side. Therefore, different flow control strategies might be applied to improve the aerodynamic performance. Design/methodology/approach The present research is focussed on the application of passive rod vortex generators (RVGs) to control the flow separation induced by strong shock waves on helicopter rotor blades. The formation and development in time of the streamwise vortices are also investigated for a channel flow. Findings The proposed RVGs are able to generate streamwise vortices as strong as the well-known air-jet vortex generators. It has been demonstrated a faster vortex formation for the rod type. Therefore, this flow control device is preferred for applications in which a quick vortex formation is required. Besides, RVGs were implemented on helicopters rotor blades improving their aerodynamic performance (ratio thrust/power consumption). Originality/value A new type of vortex generator (rod) has been investigated in several configurations (channel flow and rotor blades).

Effects of Vincristine on Endothelial Microtubules in the Spinal Cord

1976 ◽  
Vol 34 ◽  
pp. 58-59
Author(s):  
John L. Beggs ◽  
John D. Waggener ◽  
Wanda Miller
Keyword(s):  
Spinal Cord ◽  
Biological Activity ◽  
Horseradish Peroxidase ◽  
Transport Mechanism ◽  
Vasogenic Edema ◽  
Vesicular Transport ◽  
Close Proximity

Microtubules (MT) are versatile organelles participating in a wide variety of biological activity. MT involvement in the movement and transport of cytoplasmic components has been well documented. In the course of our study on trauma-induced vasogenic edema in the spinal cord we have concluded that endothelial vesicles contribute to the edema process. Using horseradish peroxidase as a vascular tracer, labeled endothelial vesicles were present in all situations expected if a vesicular transport mechanism was in operation. Frequently,labeled vesicles coalesced to form channels that appeared to traverse the endothelium. The presence of MT in close proximity to labeled vesicles sugg ested that MT may play a role in vesicular activity.

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