tailieunhanh - Air and Abrasive Acceleration_5

Tham khảo tài liệu 'air and abrasive acceleration_5', kỹ thuật - công nghệ, điện - điện tử phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Composition of Particle Jets 91 Fig. Aspects of area coverage Meguid and Rabie 1986 . a Coverage 16 b Coverage 52 p - __4 rP3 S 3 rN2 3 rN x tan 9J x 2 tan2 9J The dimensionless numbers in read as follows. The dimensionless nozzle radius is defined as follows Np rN rN -vp It is the number of particles launched in the time taken for a particle of average velocity to travel a distance equal to the nozzle radius. The dimensionless particle radius is defined as follows 92 3 Air and Abrasive Acceleration Fig. Relationship between exposure time and area coverage Tosha and lida 2001 Np rP rp vp It is the number of particles launched in the time taken for a particle of average velocity to travel a distance equal to the particle radius. The dimensionless stand-off distance is defined as follows . _ rNp x xT ------ vp It is the number of particles launched in the time taken for a particle of average velocity to travel a distance equal to the stand-off distance between nozzle exit and target surface. The stream density can be applied to the calculation of a relative distance between abrasive particles as follows Lp Lp r A1 3 p dp 6 pS This parameter characterises the ratio between the average distance of two incident particles and the particle diameters. Composition of Particle Jets 93 a Fig. Stream density Ciampini et al. 2003a . a Geometric condition b Simulation for oblique impact c Simulation for normal .