Technical Notes: Comment on the “Minimum Weight Design of Helicopter Rotor Blades with Frequency Constraints,” Journal of the American Helicopter Society, October, 1989

1990 ◽  
Vol 35 (2) ◽  
pp. 69-69
Author(s):  
Kenneth B. Amer
Keyword(s):  
Minimum Weight ◽  
Rotor Blades ◽  
Helicopter Rotor ◽  
Minimum Weight Design ◽  
Bending Fatigue ◽  
Weight Saving ◽  
Blade Root ◽  
Helicopter Rotor Blades ◽  
Weight Design ◽  
Fatigue Loads

It appears that most of the weight saving from the reference blade to the minimum‐weight blade is in the region of the blade root. Undoubtedly, the reference blade requires this weight increase to accommodate the usual bending fatigue loads at the root. The authors do not address the question of how their minimum‐weight blade would handle blade‐root fatigue loads.

Minimum Weight Design for Toroidal Shells With Strengthening Component

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Vu Truong Vu
Keyword(s):  
Minimum Weight ◽  
Optimization Methods ◽  
Plastic Instability ◽  
Optimal Shape ◽  
Minimum Weight Design ◽  
Swarm Optimization ◽  
Weight Saving ◽  
Weight Design ◽  
Internal Volume ◽  
Toroidal Shells

This article presents an approach to the minimum weight design for toroidal shells with strengthening component subject to internal pressure. The optimal shape is obtained by adjusting the geometry and wall thickness of the cross section associated with the thickness and position of the strengthening component. Constraints include first yield pressure, plastic pressures, plastic instability pressure, and internal volume of toroid. The weight saving can reach over 70% in some toroid configurations. The comparison of two optimization methods shows that differential evolution (DE) slightly outperforms particle swarm optimization (PSO) in the majority of investigated cases.

Circulation Control Span-Wise Blowing Location Optimization for a Helicopter Rotor Blade

2010 ◽  
Author(s):  
Alan M. Didion ◽  
Jonathan Kweder ◽  
Mary Ann Clarke ◽  
James E. Smith
Keyword(s):  
Stress Reduction ◽  
Rotor Blades ◽  
Helicopter Rotor ◽  
Base Line ◽  
Control Technology ◽  
Circulation Control ◽  
High Lift ◽  
Location Optimization ◽  
Helicopter Rotor Blades ◽  
Length Reduction

Circulation control technology has proven itself useful in the area of short take-off and landing (STOL) fixed wing aircraft by decreasing landing and takeoff distances, increasing maneuverability and lift at lower speeds. The application of circulation control technology to vertical take-off and landing (VTOL) rotorcraft could also prove quite beneficial. Successful adaptation to helicopter rotor blades is currently believed to yield benefits such as increased lift, increased payload capacity, increased maneuverability, reduction in rotor diameter and a reduction in noise. Above all, the addition of circulation control to rotorcraft as controlled by an on-board computer could provide the helicopter with pitch control as well as compensate for asymmetrical lift profiles from forward flight without need for a swashplate. There are an infinite number of blowing slot configurations, each with separate benefits and drawbacks. This study has identified three specific types of these configurations. The high lift configuration would be beneficial in instances where such power is needed for crew and cargo, little stress reduction is offered over the base line configuration. The stress reduction configuration on the other hand, however, offers little extra lift but much in the way of increased rotor lifespan and shorter rotor length. Finally, the middle balanced configuration offers a middle ground between the two extremes. With this configuration, the helicopter benefits in all categories of lift, stress reduction and blade length reduction.

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