Investigation of the development of laminar flow at the entrance of a two-dimensional channel,using a laser-doppler velocimeter

The results of an experimental investigation of the velocity structure of Poiseuille flow at the entrance section of a two-dimensional horizontal channel with a discontinuous velocity profile at the entrance, at Re=300 and 500, are given. The experimental facility and the technique for measuring the velocity field in this channel using a laser-Doppler velocimeter (LDV) are discussed. Velocity profiles are obtained which are concave on the channel axis, and this agrees with the results of the numerical computations of 1].