Consider laminar flow of a fluid with 3u 4 that undergoes a combined entrance process within a constant surface temperature tube of length / [fdw with a flow rate of . an engineer suggests that the total heat transfer rate can be improved if the tube is divided into 1 shorter tubes, each of length /1 //1 with a flow rate of . determine an expression for the ratio of the heat transfer coefficient averaged over the 1 tubes, each experiencing a combined entrance process, to the heat transfer coefficient averaged over the single tube, .