A Study on pneumatic turbulent internal flow with heat transfer and friction

(Modeling and experimental validation)

Abstract

The purpose of this research is a development of simulation models of pneumatic steady flow through straight uniform tubes with heat transfer and wall friction. Assuming that the tube wall temperature and the inlet air temperature are constant, the air temperature inside the tube approaches to the tube wall temperature along the flow direction and the effect of the heat transfer becomes negligibly small at the downstream region far from the entrance. We developed the two models which simulate the flow in the heat transfer region and in the adiabatic region respectively. They are serially connected to model the whole flow in the tube. We made use of feedback control techniques to solve the equations which described the two models. In the experiment the compressed air was supplied from the constant temperature tank to the copper tube which was set in the water jacket to adjust the wall temperature. The pressure at both ends of the tube and the mass flowrate were measured. The usefulness of the newly developed models was verified by comparing the simulation results with the experimental results.