Measured Blockage Effects on Bluff Bodies in Closed and Open Wind Tunnels.

摘要

The base pressure of a series of square flat plates, placed normal to the airstream, has been measured in three wind tunnels, two with a closed test section and one with an open test section. The measurements in the closed tunnels are in fair agreement with the theory due to Maskell which predicts a correction linearly dependent on C sub D S/C. A correction of -0.2 x (the closed tunnel correction) is a fair approximation to the blockage effect in the open tunnel for C sub D S/C < 0.03 though, for larger blockage, a dependence on (C sub D S/C) -squared seems more appropriate. (Author)