Heat transfer to laminar flow in converging plane walled channels with both walls heated and one wall heated one wall adiabatic is analytically obtained. The analysis is carried out for the two thermal boundary conditions of prescribed wall heat flux q1/r and qrδ. The Nusselt number for flow in converging plane walled channels depends on Reynolds number and half taper angle α. If differences in velocity distribution are ignored, there is a direct correspondence between wall heat flux qe-α(δ+1)x in parallel flow and heat flux qrδ in converging plane walled channels.
In case of q varying as 1/r, Nusselt number is usually higher than that for laminar flow in parallel channel with constant heat flux. It increases as the value of |Re|α increases, and approaches a limit value at r→0 when |Re|α→∞.
In case of q varying as rδ, however, when δ<-1, Nusselt number is higher than that with q1/r. When δ>-1, Nusselt number at r→0 falls below that for constant heat flux case in parallel channel. It decreases as the value |Re|α increases, and reduces to zero as |Re|α exceeds a critical value.
