Based on the flow characteristics and a structural characteristics of a heat exchanger with longitudinal flow of shell-side(HELFS)

simplified physical model of HELFS is presented.The mathematical model is set up on the basis of the governing equations of viscous hydromechanics.By adopting the operator splitting algorithms

the Galerkin finite element method is used to deduce the discrete equations.In order to verify the calculated fluid flow field of HELFS

the Laser Doppler Velocimetry (LDV) is used to measure the local fluid velocity values on seven sections of shell-side of HELFS.The calculation result is in good agreement with experimental data

with error of 7%—20%.It is feasible to do numerical simulation by separating HELFS into heat import section

cyclic development section and export section.The theory and procedure of numerical calculation are correct in number value.