| Popis: |
Flow characteristics of spirally coiled tubes in terms of their secondary flow and pressure drop are investigated. Four spirally coiled tubes with different curvature ratios; under constant wall temperature, are numerically simulated using ANSYS FLUENT 12.0 CFD software. In the system, water is entering the inner-most turn and flows out at the outer-most turn. To build the numerical model, a finite volume method (FVM) with an unstructured grid system is employed for solving the Navier-Stokes equations system. Correspondingly, the standard – k turbulence model is employed to predict the flow development. Here, the mass flow rate in the spirally coiled tube is set to vary within the range 0.03 - 0.12 kg/s. The numerically obtained data of the pressure drop in the spiral coils are compared with the experimental data reported in the literature. A close agreement is observed between the experimental data and the results of this study. Based on the results, a new correlation is proposed for predicting the pressure drop in horizontal spiral coils. |
