An empirical study on the pressure drop characteristics of nanofluid flow inside helically coiled tubes

作者：Fakoor Pakdaman M; Akhavan Behabadi M A^*; Razi P

来源：International Journal of Thermal Sciences, 2013, 65: 206-213.

DOI：10.1016/j.ijthermalsci.2012.10.014

• Pressure drop
• Nanofluid
• Helical and straight tubes
• MWCNT
• Experiments

In this study, pressure drop characteristics of nanofluid flow inside vertical helically coiled tubes are investigated experimentally for the laminar flow regime. The temperature of the tube wall is maintained constant at around 95 degrees C to have isothermal boundary condition Experiments are implemented for fluid flow inside helically coiled tubes and a straight one. A wide range of various variables is taken into account. Pitch to tube-diameter ratio ranges between 1.6 and 6.1 and coil-to-tube diameter ratio varies from 14.1 to 20.5. Heat transfer oil is used as the base fluid, and Multi-Walled Carbon NanoTubes (MWCNTs) are utilized as the additive to provide the nanofluids. The working fluids are extremely temperature dependent, so rough correlations are proposed to predict their thermo-physical properties. Regarding the experimental data, utilization of helical coiled tubes instead of straight ones increases the pressure drop exponentially. Irrespective of the tube geometry in which the fluid flows, nanofluid flows show higher rate of pressure drop compared to that of the base fluid flow. Finally according to the observations, combination of the two techniques used in this study causes the pressure of the fluid flow to drop significantly along the test section.

• 出版日期2013-3