Modeling, design, materials and fabrication of bipolar plates for proton exchange membrane fuel cell: A review

The influence of hybrid nanofluids on the performances of elliptical tube: Recent research and numerical study

Energy, exergy and economic assessments of shell and tube condenser using hybrid nanofluid as coolant

A comprehensive, multidimensional, thermal-hydraulic model is developed for the analysis of shell-and-tube heat exchanges for liquid metal services. For the shellside fluid, the conservation equations of mass, momentum and energy for continuum fluids are modified using the concept of porosity, surface premeability and distributed resistance to account for the blockage effects due to the presence of heat transfer tubes, flow baffles/shrouds, the support plates, etc. On the tubeside, heat transfer tubes are connected in parallel between the inlet and outlet plenums, and tubeside flow distribution is calculated based on the plenum-to-plenum pressure difference being equal for all tubes. It is assumed that the fluid remains single-phased on the shell side and may undergo phase-change in the tube side, thereby simulating the conditions of Liquid Metal Fast Breeder Reaction (LMFBR) intermediate heat exchanges (IHX) and steam generators (SG). The analytical model predictions are compared with three sets of test data (one for IHX and two for SG) and favorable results are obtained, thus providing a limited validation of the model.

Multidimensional numerical modeling of heat exchangers

Influence of quaternary combinations of biodiesel/methanol/n-octanol/diethyl ether from waste cooking oil on combustion, emission, and stability aspects of a diesel engine

In the last few decades biodiesel has proved to be the best alternative for the conventional diesel in many applications. Due to ever increasing demand of the mankind, the fossil fuels are depleted so much that in the near future oil scarcity is inevitable. The environmental impact that is caused by conventional diesel can be greatly reduced by using biodiesel.  The present study experimentally investigates the usage of preheated crude pongamia oil (CPOP), pongamia methyl ester (PME) and diethyl ether (DEE) biodiesel blends on an unmodified diesel engine running on its full throttle. Preheating crude pongamia oil reduces its viscosity to a great extent, which is always an issue with biodiesel fuels. In the present study the performance and emission parameters are evaluated for DBD 1 (CPOP 60% and D 40%), DBD 2 (PME 60% and D 40%) and DBD 3 (CPO 60%, DEE 15% and D 25%). The experimental data obtained for performance and emission parameters for biodiesel fuels are checked in par with mineral diesel. For all the biodiesel blends, the trend for BTE is found increasing whereas BSFC followed a decreasing trend at all operated loads. Particulate emissions except HC and NOx are lesser in biodiesel blends than diesel due to the presence of dissolved oxygen. Also, the addition of diethyl ether to crude pongamia has significant impact on performance improvement and reduced emissions when compared to other blends. From this experimental study it is concluded that pongamia oil because of its rich availability in India can be the best fuel for blending with diesel and using for small and medium scale energy producing vehicles.

https://ijrer.com/index.php/ijrer/article/download/4761/pdf

An Experimental Study on Performance and Emissions of a Direct Ignition Diesel Engine With Crude Pongamia, Pongamia Methyl Ester and Diethyl Ether Blended With Diesel

A three dimensional numerical study has been carried out to investigate the effect of various geometric shapes and slit angle on performance of the bladeless fan for various aerodynamic profiles. Aerofoils considered for the present study are E169, E473 and E479 which are then reformed into a typical bladeless fan arrangement. The numerical model of bladeless fan encompassing the outer domain is discretized tetrahedrally through finite volume approach using ANSYS ICEMCFD 20.0 and the necessary boundary conditions are specified in the ANSYS Fluent 20.0 pre-processor. The three dimensional fluid flow variations through and across the aerofoil have been simulated by solving the appropriate governing equations namely continuity and Reynolds Averaged Navier-Stokes equations (RANS). The turbulence induced in the fluid is modelled using SST k-ωmode of closure. Numerically predicted results of lift, drag and streamwise velocity decay along the jet centreline of a cylindrical channel are compared with literature and a very close agreement exists between the two. Upon validation, geometric shapes - circular and square cross section with aspect ratios of 1, 1,5 and 2 and slit angles of 20, 40, 60 and 80 degree for all the above three aerofoil configurations are analysed numerically for various inlet Reynolds number. Pressure, velocity contours and stream line across the bladeless fan are presented and discussed. From the study it is observed that Eppler 473 aerofoil profile with slit thickness of 1 mm and slit angle of 80° provided the maximum discharge ratio of 34.17 for an inlet mass flow rate of 80 LPS. 

Numerical Investigation on the Effect of Geometric Shape and Outlet Angle of a Bladeless Fan for Flow Optimization using CFD Techniques

This paper presents the effect of number of tubes, unequal baffle spacing and tube diameter on heat transfer and pressure drop characteristics of a typical shell and tube type heat exchanger. Upon geometrical optimization, the second phase of this research work aims at studying the influence of Al2O3 nanofluid of 0.5%, 0.75%, 1%, 1.25% and 1.5% concentrations by admitting water along the tubes and Al2O3 nanofluid along the shell side. The shell and tube heat exchangers of various geometrical configurations are modeled using SOLIDWORKS 2015. The heat transfer and fluid flow characteristics through the heat exchanger are obtained by solving the governing equations namely continuity, momentum and energy equations using ANSYS CFX 15 CFD code. Temperature, pressure contours and velocity streamlines along the mid-plane of the shell and tube heat exchanger are obtained for various geometrical configurations and for different volume concentration of nanofluid. The heat transfer coefficient and the pressure drop for various volume fraction concentrations of the nanofluid are plotted. The use of nanofluid resulted in increase of both the pressure drop and heat transfer coefficient. The heat transfer coefficient at 1.25% volume concentration of nanofluid is found to be the optimum value.

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Numerical investigation of shell and tube heat exchanger using Al2O3 nanofluid

For the past few decades, research has scaled up in the development of environmental friendly alternative fuels such as biofuels that can replace the use of conventional fuel resources. The present work investigates the usage of Pongamia and Orange oil blended with diesel to run a compression ignition engine. Several experiments were conducted with blends of diesel, Pongamia and Orange oil in different proportions to evaluate engine performance and emission characteristics of full throttle position. The results indicate that the values of Brake Specific Fuel Consumption, Brake thermal efficiency and mechanical efficiency obtained with the use of bio-diesel blends are very close, and emissions are less when compared to diesel.

https://ijrer.com/index.php/ijrer/article/download/3373/pdf

Thundil Karuppa Raj Rajagopal

Papers

An Experimental Study on Performance and Emissions of a Direct Ignition Diesel Engine With Crude Pongamia, Pongamia Methyl Ester and Diethyl Ether Blended With Diesel

Numerical Investigation on the Effect of Geometric Shape and Outlet Angle of a Bladeless Fan for Flow Optimization using CFD Techniques

Numerical investigation of shell and tube heat exchanger using Al2O3 nanofluid

Experimental Investigation on Engine Performance and Emission Characteristics using Pongamia – Orange Oil Blends

Effect of flow fields and humidification of reactant and oxidant on the performance of scaled‐up PEM‐FC using CFD code