A Study on Heat Transfer and Pressure Drop in a Turbulent Flow Regime of Thermally Insulated and Conducting Nanofluids

2019 ◽  
Vol 8 (3) ◽  
pp. 490-499 ◽  
Author(s):  
Kashminder Singh Mehta ◽  
Lal Kundan ◽  
S. S. Mallick
1979 ◽  
Vol 101 (3) ◽  
pp. 391-396 ◽  
Author(s):  
F. W. Staub

In gas fluidized beds of large particles, a change in flow regime from bubbling flow to turbulent flow has been observed as the superficial gas velocity is increased. Solids flow and heat transfer models based on the bubbling flow regime are not generally adequate in the turbulent flow regime. A turbulent flow model is given here that is supported by limited solids flow measurements. A simplified model of the heat transfer to tube banks immersed in fluidized beds, that employs the solids flow model, is also given and is shown to be supported by data over a wide gas pressure and temperature range with particles in the 350μm to 2600μm size range.


Author(s):  
Justin Caspar ◽  
Julio Bravo ◽  
Shuoyu Wang ◽  
Ahmed Abdulridha ◽  
Sudhakar Neti ◽  
...  

Abstract The fluid flow and heat transfer inside a concrete thermal energy storage module is simulated for various heat transfer fluid flow rates and inlet temperatures. The storage performance of the module is characterized based on the volume-averaged temperature and normalized energy distribution through the block versus time. In the turbulent flow regime, induced mixing in the pipe strongly enhanced the performance of the module compared to the laminar regime. The block was able to fully charge and discharge in a turbulent flow regime, whereas that behavior was not present in the laminar flow regime. Varying the heat transfer temperature had an effect on the time rate of change of temperature as well as the charge times. As the thermal gradient increased, the initial time rate of temperature in the block increased as well as the charge time. Since the block has higher theoretical energy at a larger gradient, power over a longer duration is necessary to reach a saturation point. By characterizing the thermal performance of the module, the effect of material properties and operational parameters can be studied in order to design a module that can meet the needs of a power generation plant.


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