« April 2017 »
S M T W T F S
1
2 3 4 5 6 7 8
9 10 11 12 13 14 15
16 17 18 19 20 21 22
23 24 25 26 27 28 29
30
You are not logged in. Log in
Entries by Topic
All topics  «
ART NEWS
COMMUNITY INTEREST
DUFFY Media Publications
FASHION NEWS
REEALY?
Welcome to the Blog
Blog Tools
Edit your Blog
Build a Blog
RSS Feed
View Profile

DUFFY'S CULTURAL COUTURE
Saturday, 29 April 2017
Hybrid Flow Control Method for Simple Hinged Flap High-Lift System
Topic: COMMUNITY INTEREST

 

 


 

 

 Hybrid Flow Control Method for Simple Hinged Flap High-Lift System

 

 

 


 

 

 

 

Using sweeping jet actuators and adaptive vortex generators to create a low-drag hinged flap high-lift system NASA's Langley Research Center has created a novel process that significantly improves the effectiveness of high-lift devices on aircraft wings by utilizing a hybrid concept of both sweeping jet (SWJ) actuators for active flow control (AFC) and adaptive vortex generators (AVGs) for passive flow control. High-lift technology re-shapes aircraft wings for more lift during takeoff and landing. Conventional high-lift devices are complex and employ a significant number of parts. In addition, these complex mechanical high-lift systems (e.g., Fowler flap mechanisms) often protrude externally under the wings, resulting in increased cruise drag. Simple hinged flaps are preferable high-lift devices for low-drag cruise performance, but they are vulnerable to flow separation at high flap deflections for both trailing edge and leading edge applications. This innovation achieves higher flap deflections without flow separation while minimizing the pneumatic power requirement of AFC.
 
 
Benefits
  • Hybrid flow control enables utilization of proven vortex generator technology in high-lift configurations, while eliminating the (device-induced) parasitic drag in cruise.
  • Hybrid flow control provides the necessary lift enhancement for a simple hinged flap high-lift system.
  • Hybrid flow control approach is more compatible with the limited supply of engine bleed air available as engines idle during the landing descent.
  • Method can reduce aircraft drag by up to 3.3 counts due to elimination of Fowler flap fairings.
  • Technology is also useful for increasing the effectiveness of vertical fin / rudder systems. This leads to reduced fin size and weight, especially for the short variant of a transport aircraft.

 

Applications
 
 
  • Aerospace: All hinged flap control surfaces (e.g., flaps, elevators, and rudders) of commercial and military aircraft.
  • Marine: All hinged flap control surfaces (e.g., hydroplanes and rudders) of marine vessels.

 

The combination of AVGs with SWJ actuators creates an unparalleled and unexpected improvement in flap efficiency. This unique hybrid approach of using SWJ actuators and AVGs in combination may provide the necessary lift enhancement for a simple hinged flap high-lift system while keeping the pneumatic power requirement (mass flow and pressure) for the SWJ actuators within an aircrafts capability for system integration. For the current innovation, it is envisioned that this hybrid approach may significantly narrow/close the technology gap and enable the realization of a simple hinged flap high-lift design, which will have the benefits of lower weight (without the Fowler flap mechanism) and less cruise drag (without the external fairing for the Fowler flap mechanism). Figure 1 illustrates one example of how AVGs and the SWJ actuators can be used in combination for a simple hinged flap high-lift system. For high-lift applications with a high flap deflection angle and a significant adverse pressure gradient, both SWJs and AVGs are activated for hybrid flow separation control. When the flap is deflected to a low deflection angle, only AVGs are activated to prevent possible flow separation initiated from the trailing edge. Figure 2 shows the cruise configuration with no flap deflection and there is no flow control activation.


Posted by tammyduffy at 12:01 AM EDT
Updated: Saturday, 1 April 2017 3:47 PM EDT

View Latest Entries