Numerical evaluation of circulation control airfoil performance using Navier-Stokes methods

Author(s):  
G. SHREWSBURY
1995 ◽  
Vol 11 (2) ◽  
pp. 137-143 ◽  
Author(s):  
Liu Jingchang ◽  
Sun Mao ◽  
Wu Liyi

2004 ◽  
Vol 43 (5) ◽  
pp. 696-710 ◽  
Author(s):  
Ronald Calhoun ◽  
Frank Gouveia ◽  
Joseph Shinn ◽  
Stevens Chan ◽  
Dave Stevens ◽  
...  

Abstract An experiment investigating flow around a single complex building was performed in 2000. Sonic anemometers were placed around the building, and two-dimensional wind velocities were recorded. An energy-budget and wind-measuring station was located upstream to provide stability and inflow conditions. In general, the sonic anemometers were located in a horizontal plane around the building at a height of 2.6 m above the ground. However, at the upwind wind station, two levels of the wind were measured. The resulting database can be sampled to produce mean wind fields associated with specific wind directions such as 210°, 225°, and 240°. The data are available generally and should be useful for testing computational fluid dynamical models for flow around a building. An in-house Reynolds-averaged Navier–Stokes approach was used to compare with the mean wind fields for the predominant wind directions. The numerical model assumed neutral flow and included effects from a complex array of trees in the vicinity of the building. Two kinds of comparisons are presented: 1) direct experimental versus modeled vector comparisons and 2) a numerical metric approach that focuses on wind magnitude and direction errors. The numerical evaluation generally corroborates the vector-to-vector inspection, showing reasonable agreement for the mean wind fields around the building. However, regions with special challenges for the model were identified. In particular, recirculation regions were especially difficult for the model to capture correctly. In the 240° case, there is a tendency for the model to exaggerate the turning effect in the wind caused by the effect of the building. Two different kinds of simulations were performed: 1) predictive calculations with a reasonable but not high-fidelity representation of the building's architectural complexity and 2) postexperiment calculations in which a large number of architectural features were well represented. Although qualitative evidence from inspection of the angles of the vectors in key areas such as around the southeast corner of the building indicated an improvement from the higher-fidelity representation of the building, the general numerical evaluation indicated little difference in the quality of the two solutions.


1992 ◽  
Vol 29 (2) ◽  
pp. 243-249 ◽  
Author(s):  
S. L. Williams ◽  
M. E. Franke

2019 ◽  
Author(s):  
Taher Hajilounezhad

The effect of wind on the performance of dry indirect cooling towers in different arrangements is investigated in the present paper. Thus , there are two cases to solve the problem: At first, solving various arrangements in free conviction state, and then when exposed to wind (forced conviction ).Let consider a wind of 5 m/s velocity in order to compare different results obtained in forced conviction state in various arrangement . For the case of free conviction, towers are considered as two parallel towers, two successive towers, three towers in triangular arrangement and four towers in rectangular arrangement at equal distances. Then, velocity and pressure field are compared in different arrangements and phenomena such as chocking of tower flow due to presence of wind and interactions of various towers on each other's suction capacity in case of wind blow are investigated. Navier-Stokes equations are used in this work.


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