Posts tagged "space shuttle"
Condensation clouds form around sections of Atlantis as STS-135—the final space shuttle flight—launches from Cape Canaveral this morning. These clouds, also called Prandtl-Glauert singularities or vapor cones, form at transonic speeds when air accelerates around the vehicle. The area just behind these shock waves experiences a drop in pressure and temperature that brings a localized portion of the flow below the dew point. Rapid condensation of the moisture in the air results. Miss the launch? Watch it here.
A scale model of the Space Shuttle attached to its modified 747 carrier hangs in a NASA wind tunnel. Wind tunnel tests can be used for flow visualization, lift and drag measurements, control system checks and so forth, but mounting models correctly and safely in the tunnel is crucial. Many models use sting mounts that project forward, as this one does, in order to expose the model to freestream flow unimpeded by the mounting mechanism. Any mounts and models must also be sturdy enough that all or part of them does not break off mid-test and fly into the wind tunnel’s fans. #
Wingtip vortices mark the path of Discovery as she makes her final landing. Though not always visible, these vortices are generated by any lifting body planform and can be a major source of induced drag on the craft. Here the vortices are visible because the low pressure in the core of the vortex caused a local temperature drop below the dew point, thus causing condensation. Such vortices persist for significant lengths of time in the wake of aircraft; they are a major source of wake turbulence, which limits how frequently aircraft can take-off or land on a single runway. (Photo by Jen Scheer)