Study On Foam Fluid Flow And Heat Transfer In Circular Pipe

An experimental system was designed and installed to study the foam fluid flow and heat transfer in circular duct based on the application of foam fluid in the petroleum engineering. Combined with numerical simulation, a systematic study was carried out on the rheological model, hydraulic calculation methods and laminar forced convection heat transfer for air-water foam fluid.Experimental data showed that the rheological model of foam fluid can be described by power-law equation. The rheological equations for different conditions were determined on the basis of experimental datas. Besides, the effects of foam quality, temperature, pressure and foaming agent concentration on the rheological characterization of foam fluid were analyzed.The calculation methods of turbulent friction factor for foam fluid in pipe flow were examined with the arithmetic mean and mean relative deviation. The formulas for the turubulent friction factor of foam fluid for different rheological index were determined. A comparison was made between the turbulent friction factor formulas of Bingham fluid. The effects of Reynolds number, flow index and the ratio of yield stress and wall shear stress on the friction factor of yield-pseudoplastic fluid were analyzed.An experimental study was carried out on the laminar flow of foam fluid in circular duct. Experimental results showed that the existing formula of friction factor was accurate enough for foam fluid. The effects of foam quality, temperature, pressure and foaming agent concentration on the friction factor were examined.On the basis of Pigford formula, an examperimental correlation of convective heat transfer for foam fluid in circular pipe was developed. The effects of flow rate, foam quality, wall temperature, pressure and foaming agent concentration on the characteristics of convection heat transfer were studied. The results showed that the average Nusselt number increased with velocity, foam quality, concentration of foaming agent and pressure. And the average Nusselt number decreased with temperature.The physical and mathematical models for the flow and heat transfer of foam fluid in circular duct were established and solved numerically by SIMPLE algorithm. The results of numerical simulation were in good agreement with the experimental datas.By numerical simulation, the distribution curves of pressure and the average temperature of tube cross-section along the pipe and radial velocity were obtained. The effects of rheological parameters, velocity and different types of gas working fluid on the flow and heat transfer of foam fluid in circular tube were analyzed.