Method for Designing Three-Dimensional Swept Hybrid Wings for Icing Wind-Tunnel Tests

2019 ◽  
Vol 56 (2) ◽  
pp. 730-746 ◽  
Author(s):  
Gustavo E. C. Fujiwara ◽  
Michael B. Bragg
Keyword(s):  
Wind Tunnel ◽  
Three Dimensional ◽  
Wind Tunnel Tests

Wind tunnel tests of effects of atmospheric stability on turbulent flow over a three-dimensional hill

2005 ◽  
Vol 93 (2) ◽  
pp. 155-169 ◽  
Author(s):  
Takeo Takahashi ◽  
Shinsuke Kato ◽  
Shuzo Murakami ◽  
Ryozo Ooka ◽  
Mohamed Fassy Yassin ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Turbulent Flow ◽  
Atmospheric Stability ◽  
Three Dimensional ◽  
Wind Tunnel Tests

Numerical and Experimental Investigation on a Low-Speed Compressor Cascade With Circulation Control

2008 ◽  
Author(s):  
S. Fischer ◽  
H. Saathoff ◽  
R. Radespiel
Keyword(s):  
Wind Tunnel ◽  
Static Pressure ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Circulation Control ◽  
Two Dimensional ◽  
Compressor Cascade ◽  
Flow Topology ◽  
Wind Tunnel Tests ◽  
Low Speed

Experimental and numerical results for the flow through a stator cascade with active flow control are discussed. By blowing air through a slot close to the trailing edge of the aerofoils, the deflection angle as well as the static pressure rise in the stator are increased. The aerofoil design is representative for a 1st-stage stator geometry of a multi-stage compressor adapted for low–speed applications. To allow a reasonable transfer of the high-speed results to low-speed wind tunnel conditions, a corresponding cascade geometry was generated applying the Prandtl–Glauert analogy. With this modified cascade numerical simulations and experiments have been conducted at a Reynolds number of 5 · 105. As a reference case two-dimensional flow simulations without circulation control are considered using a Navier–Stokes solver. In the related wind tunnel tests three–dimensional conditions occur in the test rig. Nevertheless five–hole probe measurements in the wake of the blade mid section show a good agreement with the theoretical characteristics. Additional investigation along the whole blade span gives a deeper insight into the flow topology. For design conditions different blowing rates are applied. The wind tunnel tests confirm the positive benefit, which is predicted by two-dimensional calculations. The offset between simulated and measured pressure rise decreases with increasing blowing mass flows due to the reduction of the axial velocity ratio. This result is related to a redistribution of the passage flow which can only be explained in a three–dimensional analysis including the side wall influence. The benefit of the circulation control at varying blowing rates is finally characterized by the efficiency and the static pressure rise per injected energy.

A predictive critical flutter wind speed modeling for long-span bridges

2020 ◽  
Vol 23 (9) ◽  
pp. 1823-1837
Author(s):  
Kun Lin ◽  
Minghai Wei ◽  
Hongjun Liu ◽  
Huafeng Wang
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Wind Tunnel Tests ◽  
Long Span Bridges ◽  
Wind Speeds ◽  
Long Span ◽  
Aerodynamic Model ◽  
Proposed Model

In this article, a two-dimensional Lighthill aerodynamic model is first extended to three-dimensional space, and then combined with the larger Von Karman plate deformation theory, a model for predicting the critical flutter wind speeds of long-span bridges in the primary design is proposed. The predictions of the presented model are compared to the results of wind tunnel tests for five long-span bridges with different main girder section forms. After that, based on the proposed model, the effects of width to span ratio and thickness to span ratio on the critical flutter wind speeds of long-span bridges are investigated. The results show that the differences between the proposed model and wind tunnel tests are only 7%–14%. Therefore, the presented model can assess the flutter wind speed in preliminary design stages of a bridge. The results also reveal that width to span ratios between 1/30 and 1/10 and thickness to span ratios between 1/300 and 1/100 are optimal for long-span bridges.

A Multiple Disk Probe for Inexpensive and Robust Velocimetry

1999 ◽  
Vol 121 (2) ◽  
pp. 446-449 ◽  
Author(s):  
Sheldon I. Green ◽  
Steven N. Rogak
Keyword(s):  
Wind Tunnel ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
The Other ◽  
Small Range ◽  
Wind Tunnel Tests ◽  
Pressure Transducers ◽  
Three Components

A novel velocimeter consisting of multiple orthogonal disks fitted with pressure transducers has been developed. Dynamic pressure differences are measured between the center of one disk face and the center of the other face, on each of the disks. While previously-developed anemometers based on dynamic pressure differences (such as yaw or three-hole probes) can only measure velocities with a small range of directions, the new disk probe can measure three components of velocity, even in highly three-dimensional flows where the approximate direction of the flow is not known. Wind tunnel tests have shown the velocimeter to be quite accurate; it can measure velocities to ±1.4% and wind directions to ±4 deg. The velocimeter is very robust and therefore can make measurements in environments too harsh for most other velocity transducers.

Permissible three-dimensional testing in a two-dimensional adaptive wall wind tunnel

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 749-750
Author(s):  
David Sumner ◽  
Ewart Brundrett
Keyword(s):  
Wind Tunnel ◽  
Three Dimensional ◽  
Two Dimensional
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