Wind-tunnel measurements of flow field characteristics around a heated model building

1993 ◽  
Vol 50 ◽  
pp. 139-151 ◽  
Author(s):  
B. Ruck
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Model Building ◽  
Wind Tunnel Measurements ◽  
Flow Field Characteristics

Jets in a Crossflow: Effects of Geometry and Blowing Ratio

1999 ◽  
Vol 121 (2) ◽  
pp. 373-378 ◽  
Author(s):  
M. J. Findlay ◽  
M. Salcudean ◽  
I. S. Gartshore
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Film Cooling ◽  
Density Ratio ◽  
Mean Velocity ◽  
Cooling Effectiveness ◽  
Film Cooling Effectiveness ◽  
Flow Field Characteristics ◽  
Square Jets ◽  
Inlet Conditions

The flow field characteristics of three different geometries of square jets in a crossflow at various blowing ratios are examined. The geometries considered are: perpendicular, streamwise-inclined, and spanwise-inclined jets. The inclined jets are at a 30 deg angle to the wind tunnel floor. Mean velocity and turbulence measurements along with film cooling effectiveness and scalar transport data were obtained. Jet-to-crossflow blowing ratios of 1.5, 1.0 and 0.5 are used with a density ratio of 1. It is shown that the flow field at the jet exit is strongly influenced by the crossflow as well as by the inlet conditions at the entrance to the jet orifice. The strong streamline curvature which is present in the perpendicular and spanwise injection cases appears to result in the greatest turbulence anisotropy. The film cooling effectiveness is best at the lowest blowing ratios as the jet is deflected strongly towards the floor of the wind tunnel, although the improvement is more significant for the streamwise injection case.

Wind Effects on Air-Cooled Condensers: Wind-Tunnel 2-D Flow Fields for Base Case, Wind Screens, and Louvers

2017 ◽  
Author(s):  
Ryan S. Parker
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Flow Field ◽  
Mitigation Measures ◽  
Horizontal Wind ◽  
Base Case ◽  
Hot Wire ◽  
Horizontal Wind Speed ◽  
Air Cooled Condensers ◽  
Wind Tunnel Measurements

Detailed 2-axis hot-wire anemometry measurements were conducted around a scale Air-Cooled Condenser (ACC) model within an atmospheric boundary layer wind-tunnel. The measurements were taken for the “standard” flow field, as well as the effects of using partial wind screens and louvers as mitigation measures. This provides a representation of the complex 2-D flow field present underneath an operating ACC when subjected to various speed cross winds. Optimal ACC operation is achieved when all fans generate a uniform flow pattern into the plenum chamber of the ACC, and this is dependent on the speed and direction of the air at the inlet. The wind-tunnel measurements support the assertion that wind screens reduce the horizontal wind speed directly downstream; however, this comes with a marked increase in turbulence. The results suggest a wind-screen covering a smaller portion (6% tested) of the ACC inlet may be more beneficial than the more common 50% coverage.

Study on the Technology of Stabilization of Sands Using Aeolian Sand Bag in the Desert Area

2014 ◽  
Vol 501-504 ◽  
pp. 2365-2369
Author(s):  
Guang Li Sun ◽  
Qiang Xin ◽  
Hong Zhang ◽  
Jun Bao Luo
Keyword(s):  
Wind Speed ◽  
Wind Tunnel ◽  
Flow Field ◽  
Field Tests ◽  
Desert Area ◽  
Aeolian Sand ◽  
Speed Reduction ◽  
Fixation Effect ◽  
Flow Field Characteristics ◽  
Desert Areas

Based on "controlling sand to fix sand, managing sand with sand", aiming to the problems of sand hazard in the northwest desert area during the highway construction, the new technique of sand fixation is formed by bags of using widely distributed desert aeolian sand. The flow field characteristics of aeolian sand barrier with fins & nofins are analyzed by wind tunnel tests, the influence of sand barrier forms and specifications to wind speed reduction ratio and roughness are researched by field tests as well as sand fixation effect, the results can provide the guidance and application value to sand fixation engineer of the desert areas

Characteristic model-based adaptive control for cryogenic wind tunnels

2020 ◽  
pp. 014233122096065
Author(s):  
Chenhui Yu ◽  
Fei Liao ◽  
Haibo Ji ◽  
Wenhua Wu
Keyword(s):  
Reynolds Number ◽  
Wind Tunnel ◽  
Flow Field ◽  
Control Problem ◽  
Mimo System ◽  
Adaptive Controller ◽  
Characteristic Model ◽  
Model Based ◽  
Field Control ◽  
Cryogenic Wind Tunnel

With the increasing requirement of Reynolds number simulation in wind tunnel tests, the cryogenic wind tunnel is considered as a feasible method to realize high Reynolds number. Characteristic model-based adaptive controller design method is introduced to flow field control problem of the cryogenic wind tunnel. A class of nonlinear multi-input multi-output (MIMO) system is given for theoretical research that is related to flow field control of the cryogenic wind tunnel. The characteristic model in the form of second-order time-varying difference equations is provided to represent the system. A characteristic model-based adaptive controller is also designed correspondingly. The stability analysis of the closed loop system composed of the characteristic model or the exact discrete-time model and the proposed controller is investigated respectively. Numerical simulation is presented to illustrate the effectiveness of this control method. The modeling and control problem based on characteristic model method for a class of MIMO system are studied and first applied to the cryogenic wind tunnel control field.

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