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An extension to the basic lattice-BGK algorithm is presented for modeling a simulation region as a porous medium. The method recovers flow through a resistance field with arbitrary values of the resistance tensor components. Corrections to a previous algorithm are identified. Simple validation tests are performed which verify the accuracy of the method, and demonstrate that inertial effects give a deviation from Darcy's law for nominal simulation velocities.

The porous media model was improved to simulate the flow field of a shell-tube heat exchanger with spiral bend tubes. The improved porous medium model can be used to control the fluid flow direction. On the tube side, the streamline was along the spiral bend tubes. The fluid velocities and pressure drops on the tube and shell sides agree well with the experimental values. The fluid flow on the shell side is little affected by the spiral bend structure. The thermal stress of the spiral bend tubes was analyzed. The thermal stress of the spiral bend tubes is much smaller than the thermal stress of the straight tube. The thermal stress at the bend part decreases with the increase of bending angles.