Pitch Variations Study on Helically Coiled Pipe in Turbulent Flow Region Using CFD

CFD analysis of single-phase flows inside helically coiled tubes

It has been well established that heat transfer in a helical coil is higher than that in a corresponding straight pipe. However, the detailed characteristics of fluid flow and heat transfer inside helical coil is not available from the present literature. This paper brings out clearly the variation of local Nusselt number along the length and circumference at the wall of a helical pipe. Movemen...

Manipulating Flow Structures in Turbulent Pipe Flow

Two different tools, the non-empirical resolvent analysis and the data-based dynamic mode decomposition, are employed to assess the changes induced by transpiration in the dynamics of a turbulent pipe flow. The focus is on very large-scale motions. Both analyses permit the observation of streamwise waviness in the large flow structures and how the transpiration can inhibit fluctuation in locali...

Helically Coiled Heat Exchangers

Comparison of convective heat transfer of turbulent nanofluid flow through helical and conical coiled tubes

Application of nanofluid and coiled tubes are two passive methods for increasing the heat transfer. In the present study, the turbulent flows of water and nanofluid in coiled tubes heat exchanger were numerically studied. CuO-water nanofluid containing 1 vol% copper oxide nanoparticles was used and single-phase approach was considered for nanofluid flow. The effect of different geometrical para...

Asymptotic scaling in turbulent pipe flow.

The streamwise velocity component in turbulent pipe flow is assessed to determine whether it exhibits asymptotic behaviour that is indicative of high Reynolds numbers. The asymptotic behaviour of both the mean velocity (in the form of the log law) and that of the second moment of the streamwise component of velocity in the outer and overlap regions is consistent with the development of spectral...