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 α_c and α_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 α_c and α_d were found to govern the flow distribution independently of each other. varying α_c, α_d and the Reynolds number respectively, a correlation of optimal flow distribution is obtained for laminar fow in manifolds as follows; α_d·Re _w ^m =K where acu _c≥1/4. The proposed correlation makes predictions possible for wide ranges of α_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.