ABSTRACT
This chapter examines flow of and heat transfer to or from a fluid flowing in a conduit. The relationship between temperature profile and heat transfer at a bounding surface is defined in terms of the convection coefficient, which was introduced in Newton’s law of cooling. Hydro-dynamic and heat-transfer solutions are presented for laminar, and then again for turbulent, flow. There are two objectives in the analysis of heat transfer in closed conduits. One is to relate the heat transferred to the temperature change experienced by the fluid. The second is to relate the heat transferred to the fluid to the difference in temperature between the wall and the fluid. The heat-transfer coefficient relates the heat flux to the difference between the bulk-fluid and the wall temperature. The chapter considers the turbulent-flow heat-transfer problem. The entrance length for turbulent flow is shorter than that for laminar flow because of turbulent mixing effects.
