[kach22i]

Sept. 7, 2016
NASA to Shine Lasers on Future Aircraft Concept
https://www.nasa.gov/feature/langley/nasa-to-shine-lasers-on-future-aircraft-concept

But for this test it looks a little different. The top of it has been painted in non-reflective matte black to accommodate laser lights that will sweep across the model in sheets. NASA and Boeing researchers will use those laser sheets combined with smoke in the technique known as particle imagery velocimetry or PIV. That will map the airflow over the model...................

So if engineers have to worry about airflow – why change where the engines are? Researchers say putting them on top of the plane helps shield noise, especially from people on the ground, and contributes toward NASA's goals of developing greener, quieter planes.