Comparison of Experimental and Theoretical Turbulence Reduction from Screens, Honeycomb, and Honeycomb-Screen Combinations

The Importance of Turbulence Reduction in Assessment of Wind Tunnel Flow Quality

“…Various methods such as employment of honeycombs [13,14], anti turbulence screens [15][16][17], and appropriate contraction ratio [18] are possible means to reduce the turbulence level in wind tunnels. In an attempt to improve the test section flow quality, sudden expansion downstream of the corner turning vanes was incorporated into the wind tunnel [19].…”

“…Furthermore, the choice of appropriate screens is also difficult. Theoretically, the screens which are used for turbulence reduction should have porosity greater than 0.57 [14,22]. Screens with smaller porosity suffer from a flow instability that appears in the test section.…”

Quantitative Mixing Measurements of a Supersonic Injection COIL Nozzle with Trip Jets

“…Scheiman and Brooks studied honeycomb and mesh screen combinations for reducing flow turbulence and conclude that the honeycomb that is used to reduce lateral turbulence should be followed by a screen to reduce the axial turbulence created by the honeycomb. 57 With their published data, it is evident that a finer mesh screen has greater turbulence reduction. Two mesh screens equal in size, or in cascade starting with the largest mesh first, can be used to suppress the axial turbulence.…”

Design, Construction and Commissioning of the Braunschweig Icing Wind Tunnel

“…An influence on the longitudinal (parallel to the main flow direction) and lateral flow structures (perpendicular to the main flow direction) has to be distinguished (Scheiman and Brooks (1981)). The honeycomb reduces both the lateral components of mean velocity and of the larger turbulent eddies, where as the screens reduce the longitudinal components of 5 turbulence or mean-velocity variations across the sectional area.…”