Application of the PSP Technique in Low Speed Wind Tunnels

2006 ◽  
pp. 41-49 ◽  
Author(s):  
U. Henne
Keyword(s):  
Wind Tunnels ◽  
Low Speed

The design of low-speed wind tunnels

1964 ◽  
Vol 5 ◽  
pp. 1-69 ◽  
Author(s):  
P. Bradshaw ◽  
R.C. Pankhurst
Keyword(s):  
Wind Tunnels ◽  
Low Speed

Highlights of the Lockheed Martin F-35 STOVL jet effects programme

2009 ◽  
Vol 113 (1140) ◽  
pp. 119-127 ◽  
Author(s):  
R. Hoggarth ◽  
Richard Mange
Keyword(s):  
Wind Tunnel ◽  
System Development ◽  
Ground Effect ◽  
Wind Tunnels ◽  
Wind Tunnel Model ◽  
Low Speed ◽  
Test Conditions ◽  
Tunnel Model ◽  
Testing Techniques ◽  
Flight Regimes

Abstract This paper presents the highlights of the F-35 STOVL Jet Effects (SJE) test effort during the complete four years of the System Development and Demonstration phase. A new 12%-scale F-35 SJE model was tested in the German-Dutch wind-tunnels Large Low Speed Facility in order to gather STOVL jet-induced Forces and Moments. Ten separate test entries were conducted, covering all STOVL flight regimes from pure hover in ground effect through transition to wing borne flight. This paper will present an overview of this program, including a detailed description of the wind-tunnel model, testing techniques, test conditions, and accomplishments.

scholarly journals Experimental Research on an Active Sting Damper in a Low Speed Acoustic Wind Tunnel

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Jinjin Chen ◽  
Xing Shen ◽  
Fanfan Tu ◽  
Ehtesham Mustafa Qureshi
Keyword(s):  
Wind Tunnel ◽  
Wind Tunnels ◽  
Low Speed ◽  
Model Flow ◽  
Vibration Problems ◽  
Flow Turbulence ◽  
Active Damper ◽  
Flow Interference ◽  
Piezoelectric Devices ◽  
Algorithm Verification

Wind tunnels usually use long cantilever stings to support aerodynamic models in order to reduce support system flow interference on experimental data. However, such support systems are a potential source of vibration problems which limit the test envelope and affect data quality due to the inherently low structural damping of the systems. When exposed to tunnel flow, turbulence and model flow separation excite resonant Eigenmodes of a sting structure causing large vibrations due to low damping. This paper details the development and experimental evaluation of an active damping system using piezoelectric devices with balance signal feedback both in a lab and a low speed acoustic wind tunnel and presents the control algorithm verification tests with a simple cantilever beam. It is shown that the active damper, controlled separately by both PID and BP neural network, has effectively attenuated the vibration. For sting mode only, 95% reduction of displacement response under exciter stimulation and 98% energy elimination of sting mode frequency have been achieved.

A Simple Rolling Method for Ip

1953 ◽  
Vol 57 (510) ◽  
pp. 419-420
Author(s):  
P. T. Fink
Keyword(s):  
Imperial College ◽  
Wind Tunnels ◽  
Swept Wing ◽  
Viscous Effects ◽  
Low Speed ◽  
Rolling Method ◽  
The Stability

Aerodynamic theory may be used with reasonable confidence to estimate the low-speed value of the stability derivative Ip for wings of most plan forms under quasi-steady conditions so long as viscous effects are unimportant. Wind tunnels tests are made to cover other cases such as the partially stalled swept wing, but the writer has heard of a difficulty encountered by a firm when using the free-rolling method. A variant of that technique in which this difficulty is avoided and which has been used at Imperial College for some years may be of interest.

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