Yoshihisa AIZU, Hiroyuki WASHIYAMA and Hiromichi MISHINA

Department of Mechanical Systems Engineering, Muroran Institute of Technology, 27-1, Mizumoto-cho, Muroran 050, Japan

(Accepted August 15, 1994)

Conventional phase Doppler systems are useful for sizing particles in the order of microns, but sensitive to the Gaussian beam defect which can cause sizing errors. The defect can be significant when a large size is measured. In this paper, we present a new phase Doppler system using a planar optical layout which permits large particles to be measured in a forward scattering scheme without the Gaussian beam errors. The optical system design is discussed by numerical simulation based on the Mie theory.

Key words : particle sizing, phase Doppler anemometry, velocity measurements, trajectory ambiguity, generalized Lorenz-Mie theory