Wind tunnel measurements of the trailing vortex development behind asweptback wing - Effect of simulated jet engines on the flow field

Author(s):  
Z. EL-RAMLY ◽  
W. RAINBIRD
Author(s):  
Ryan S. Parker

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.


Author(s):  
Chenhui Yu ◽  
Fei Liao ◽  
Haibo Ji ◽  
Wenhua Wu

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.


AIAA Journal ◽  
10.2514/2.841 ◽  
2000 ◽  
Vol 38 (10) ◽  
pp. 1879-1888 ◽  
Author(s):  
R. Yano ◽  
V. Contini ◽  
E. Plonjes ◽  
P. Palm ◽  
S. Merriman ◽  
...  

2011 ◽  
Vol 97-98 ◽  
pp. 698-701
Author(s):  
Ming Lu Zhang ◽  
Yi Ren Yang ◽  
Li Lu ◽  
Chen Guang Fan

Large eddy simulation (LES) was made to solve the flow around two simplified CRH2 high speed trains passing by each other at the same speed base on the finite volume method and dynamic layering mesh method and three dimensional incompressible Navier-Stokes equations. Wind tunnel experimental method of resting train with relative flowing air and dynamic mesh method of moving train were compared. The results of numerical simulation show that the flow field structure around train is completely different between wind tunnel experiment and factual running. Two opposite moving couple of point source and point sink constitute the whole flow field structure during the high speed trains passing by each other. All of streamlines originate from point source (nose) and finish with the closer point sink (tail). The flow field structure around train is similar with different vehicle speed.


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