Fluid flow and heat transfer characteristics past four elliptic cylinders arranged in square configuration are numerically investigated in this study. An in-house finite element method code based o...

Effect of Cylinder Arrangement on Fluid Flow and Heat Transfer Characteristics past Four Elliptic Cylinders

The thermo-fluidic performance of SiO2-water nanofluid (NF) flow inside a horizontal tube of circular cross section were examined applying constant heat flux. An aqua based dispersion of SiO2 nanopowders with 16.58 nm average particle diameter were used as the
 working fluid with 0.15–0.35 vol.%. Experiments are conducted in the Reynolds number (Re) range of 2798.96–27989.62 maintaining the bulk temperature of the flow at 45 °C. Thermo-physical properties namely conductivity (k) and viscosity (μ) of NF were
 determined at various temperatures range of 25–65 °C. Maximum 13% enhancement in k and a maximum of 20% enhancement in μ were obtained at 0.35 vol.% as compared to basefluid. Heat transfer and friction factor (f) were increased with enhancing concentration
 and Re. The Nusselt number (Nu) increased upto 40% along with a maximum increase of 28.57% in f as compared to their basefluid. New empirical correlations for Nu and f of nanofluids were developed. Finally, a figure of merit (FOM) was determined, which reveals
 the potency of nanofluids as working fluid for rapid cooling applications.

Enhanced Thermo-Fluidic Performance of Aqueous SiO2 Nanofluid Flow Through a Horizontal Tube—An Experimental Investigation

Steady and unsteady numerical investigations of laminar fluid flow and heat transfer in a 180∘ bend with bypass

Experiments on air-water two-phase flows in a horizontal U-bend placed in the vertical plane were carried out to investigate effects of pipe bending on the void fraction. The inner diameter and the bend radius of curvature were 8 and 24.3 mm, respectively, so that the dimensionless bend diameter was 6. The flow patterns dealt with were plug, slug and annular flows. The void fractions in the bend and the straight section were measured by using quick-closing valves and the void fraction distribution was evaluated with an image processing method. The applicability of available correlations for the void fraction in the straight pipe was also discussed. For the straight pipe, the void fractions of the plug and slug flows can be accurately evaluated using the Smith correlation, whereas in the annular flow regime the Cioncolini and Thome correlation and the Mauro et al. liquid film thickness model give better agreement with the data. The bend void fractions in the downward and upward flows agree well with those for the pipe diameter of 26 mm given in literature, implying that the diameter effect on the void fraction is weak. The Usui et al. void fraction correlation gives reasonable evaluation for downward flows. 

Void fraction of air-water two-phase flows in a vertically placed horizontal U-bend

A numerical simulator that can handle a finned-tube heat exchanger with a complex refrigerant circuitry is presented. The model is based on a tube-by-tube approach in which each tube is considered ...

Design of a Numerical Simulator for Finned-Tube Heat Exchangers with Arbitrary Circuitry

Numerical studies on fluid flow and heat transfer through a two-dimensional 180-degree sharp bend are performed using an in-house code based on streamline upwind Petrov-Galerkin finite element meth...

Chandramouli Koushik

Papers

Steady and Unsteady Forced Convective Heat Transfer Analysis in 180 Degree Bend