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.

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.

scholarly journals Experimental and Numerical Studies on Static Aeroelastic Behaviours of a Forward-Swept Wing Model

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yan Ouyang ◽  
Kaichun Zeng ◽  
Xiping Kou ◽  
Yingsong Gu ◽  
Zhichun Yang
Keyword(s):  
Wind Tunnel ◽  
Dynamic Pressure ◽  
Wind Tunnel Test ◽  
Swept Wing ◽  
Lattice Method ◽  
Model Calculations ◽  
Wind Tunnel Tests ◽  
Model Based ◽  
Wing Model ◽  
Fidelity Model

The static aeroelastic behaviours of a flat-plate forward-swept wing model in the vicinity of static divergence are investigated by numerical simulations and wind tunnel tests. A medium fidelity model based on the vortex lattice method (VLM) and nonlinear structural analysis is proposed to calculate the displacements of the wing structure with large deformation. Follower forces effect and geometric nonlinearity are considered to calculate the deformation of the wing by finite element method (FEM). In the wind tunnel tests, the divergence dynamic pressure is predicted by the Southwell method, and the static aeroelastic displacement is measured by a photogrammetric method. The results obtained by the medium fidelity model calculations show reasonable agreement with wind tunnel test results. A high fidelity model based on coupled computational fluid dynamics (CFD) and computational structural dynamics (CSD) predicts better results of the wing tip displacement when the freestream dynamic pressure is approaching the divergence dynamic pressure.

Effects of Sensor Shape on Oscillating Pressure Measurements With Wind-Tunnel Test Confirmation

2006 ◽  
Author(s):  
David W. Wu ◽  
Hwang Choe
Keyword(s):  
Wind Tunnel ◽  
Pressure Sensor ◽  
Pressure Wave ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Wind Tunnel Test ◽  
Flow Patterns ◽  
External Flow ◽  
Pressure Measurements ◽  
Significant Correction

This paper summarizes the effects of the pressure sensor shape on the dynamic oscillating pressure measurements when the pressure wave modulating along the steam/air flow path is to be characterized. In the study presented in the paper, a three-dimensional CFD model of the external flow around the protruding, dome-shaped sensor was developed to evaluate the effects of the sensor shape on the external flow pattern, and the detailed flow patterns were studied with this protruding, dome-shaped sensors and compared with the flow patterns for the flush mounted sensors. Then, a one-dimensional analysis was done to predict that the dynamic pressures measured with the protruding sensor do not require significant correction, and this was later supported by wind tunnel tests. The amplitude of the dynamic pressure measured on the protruding sensor was determined to be ranging from 0 to 8% higher than measured by a flush mounted pressure sensor. The frequency of the pressure wave is not affected by the presence of the protrusion.

Experimental Investigation on Underwater Buckling of Thin-Walled Composite and Metallic Structures

2016 ◽  
Vol 138 (6) ◽  
Author(s):  
Michael Pinto ◽  
Helio Matos ◽  
Sachin Gupta ◽  
Arun Shukla
Keyword(s):  
Pressure Pulse ◽  
Dynamic Pressure ◽  
Three Dimensional ◽  
Image Correlation ◽  
Local Pressure ◽  
Metallic Structures ◽  
Full Field ◽  
Pressure Transducers ◽  
Flow Energy ◽  
Filament Wound

An experimental study on the underwater buckling of composite and metallic tubes is conducted to evaluate and compare their collapse mechanics. Experiments are performed in a pressure vessel designed to provide constant hydrostatic pressure through the collapse. Filament-wound carbon-fiber/epoxy, glass/polyester (PE) tubes, and aluminum tubes are studied to explore the effect of material type on the structural failure. Three-dimensional digital image correlation (DIC) technique is used to capture the full-field deformation and velocities during the implosion event. Local pressure fields generated by the implosion event are measured using dynamic pressure transducers to evaluate the strength of the emitted pressure pulse. The results show that glass/PE tubes release the weakest pressure pulse and carbon/epoxy tubes release the strongest upon collapse. In each case, the dominating mechanisms of failure control the amount of flow energy released.

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