Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Airflow question

  1. Feb 1, 2005 #1
    Outside, I have a south-facing 3'x8' banner that is hung on a fixed sign connected to an L-shaped building. The wall that the banner is on is the inner vertical wall of the L-shape. It is approximately 12-15 inches away from the wall.

    The sign is a big metal sign (approx 4'x20') with lights housed inside. I have cords that tie around the ends of the sign for the banner to hang down. The banner is anchored by 2 stakes I have placed in the ground.

    I am concerned whether air flow created by the wind could create enough pressure/force between my banner and the wall such that the banner could act as a sail and place stress that could damage the sign.

    Any advice would be gretaly appreciated.

  2. jcsd
  3. Feb 1, 2005 #2


    User Avatar
    Science Advisor
    Gold Member

    What's the banner made of? What is it tied onto the sign/stakes with? How taut is it? What wind conditions can you expect around the building?
  4. Feb 1, 2005 #3
    The banner is made of vinyl. The top two corners of the banner are tied on to opposite ends of the sign by cotton cord (approx. 5mm diam), and it is not doubled over. The bottom corners of the banner are anchored down by stakes that have been driven into the soil and are tied together with 30-40 lb fishing line. The banner is taught enough so that it looks flat and even in appearance. weight of the banner rolled up is btwn 1-2 lbs. Wind conditions at this time are quite mild. I cannot imagine that it could get too strong as there is a wall that lies perpendicular just 5-10 m to the west of the banner.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook