Laser scanning applied for ice shape measurements

- A laser scanning method is adapted to measure 3-D ice shapes growing on an airfoil in an icing wind tunnel.
- The method is verified on an ice frustum made from mold and casting.
- The effectiveness of this method is proven in an icing wind tunnel experiment.
- The temporal evolution of 3-D rime ice shapes is measured continuously without using any opaque spraying.

We proposed a 3-D ice shape measurement technique through laser light sheet scanning. The method was first verified on a plastic frustum which was printed by a 3-D rapid prototyping printer. Then, the method was further verified on a clear ice frustum that was made by mold and casting from the plastic frustum. To increase reflectance of clear ice, a thin layer of frost was grown on the ice surface. Both results show good agreement with true data. At last, the method was utilized to measure and digitize the temporal evolution of rime ice shapes and the final mixed ice shape on the leading edge of a NACA 0012 airfoil in an icing wind tunnel. The measurement at the end of ice accretion was compared with hand trace results. Results are very promising for future ice growth measurements in icing wind tunnels.