New ONERA set-ups for the characterization of the resistance of materials to liquid and solid impacts

ONERA has been involved in rain erosion studies since 1973. Rotating arms were used firstly to characterize the resistance of materials with droplet velocities in the range 200-300 m/s. In the 1990's, the Cavendish Laboratory developed a new apparatus, called MIJA (Multiple Impact Jet Apparatus), which can automatically produce water jets at high velocities. ONERA has been using a MIJA apparatus since 1994. The set-up was first validated in the range 200-300 m/s by comparison with rotating arm results. It is used now up to 600 m/s. The possibility of characterizing in-shape samples like radomes, as well as the determination of the influence of temperature and stress in the samples, were studied. A second water jet apparatus called SIJA, is in use since mid 1998. It allows rain erosion resistance measurements up to 1000 m/s. The possibility of characterization of material impact resistance was completed by another set-up called SPARC (Solid Particle Rebound Characterization apparatus) devoted to solid particle impact studies up to 190 m/s. Using two-dimensional laser velocimetry measurement, SPARC allows the determination of the angle and the velocity of rebound of a solid particle on a target.