Flow distribution in manifolds for low Reynolds number flow

This paper addresses the fundamental flow distribution question of how to design manifolds of low Reynolds number flow with both numerical analysis and experiments. The present study introduces new parameters of a(c) and a(d), defined as the ratio of header diameter to header length in combining and dividing manifolds, the parameters which are not clearly considered in the previous studies of flow distribution in manifolds. The parameters of a(c) and a(d) were found to govern the flow distribution independently of each other. Varying a(c), a(d), and the Reynolds number respectively, a correlation of optimal flow distribution is obtained for laminar fow in manifolds as follows; a(d).Re-omega(m)=K where a(c) greater than or equal to 1/4. The proposed correlation makes predictions possible for wide ranges of a(d) and Re-W. Also, the present numerical results show satisfactory agreements with those of flow visualization. From the flow visualization, recirculating flow regime was observed at the inlet of each channel, in which hot spots may occur due to small velocities. The size of recirculating flow regime is strongly dependent on the Reynolds number and is smaller for optimal cases than others.