A uniform flow past two unequal sized square cylinders arranged in a side-by-side pattern and at a Reynolds number of 50,000 has been investigated using large eddy simulation (LES) technique. The modelling of sub-grid scales of turbulence is done using the Smagorinsky model. The effect of the transverse gap ratio (T/D) on the flow characteristics has been studied. Numerical simulations are carried out for five different transverse gap ratios (T/D), namely 1.120, 1.250, 1.375, 1.750 and 2.500. Results in terms of the aerodynamic forces, Strouhal number, mean base pressure coefficient, streamlines, vorticity, surface pressure distribution, normal and shear stresses are presented. A shift in the stagnation point for the small square cylinder from the centre of its front face towards its gap side is seen at smaller T/D ratios. The presence of a jet-like flow seen in the gap side is more pronounced at T/D = 1.12. A biased gap side flow towards the near wake of the small square cylinder is seen at smaller T/D ratios. No interference effect is seen at T/D = 2.5. The flow behaviour is similar to that of the isolated square cylinder at this gap ratio.

The influence of rounded corners on the aerodynamic forces and flow interference has been studied in detail for a uniform flow past two side-by-side arranged square cylinders. The Reynolds number (Re) based on the cylinder diameter (D) and free stream velocity (U∞) is 100. Numerical simulations are carried out for seven different transverse gap ratios (T/D), each with a minimum and maximum corner radius. An inbuilt finite difference code with staggered arrangement of flow variables is used to discretize the governing equations. The concept of immersed boundary method (IBM) is employed to simulate flow around rounded corners using the regular Cartesian grids. The computational code was validated for flow past an isolated circular cylinder, square cylinder, and two equal sized circular cylinders and the results were found to be in very good agreement with available literatures. In the present study, results in terms of the mean and rms values of lift and drag coefficients, Strouhal number, phase diagrams, and contours of streamlines and vorticity are presented. As the corner radius is increased, a reduction in the drag force is observed. There exists a significant effect of gap ratio and corner radius on the phase angle of lift and drag coefficients. Three different flow patterns, namely the single bluff body flow, biased gapside flow, and two independent bluff body flows, were observed from this study.

In this experimental study, the center point of our work is to evaluate the impact of dimethyl carbonate (DMC) fuel blended with diesel with regard to the engine performance, emissions, and combustion characteristics in dual fuel engine fueled by biogas at various DMC proportions and biogas flow rates. A water-cooled, four stroke, single cylinder Compression Ignition (CI) engine is adjusted to run in dual fuel mode. A simulated biogas is obtained by mixing CH₄ and CO₂ that are kept in red and black cylinders, respectively. Throughout the experimental process the engine is run at a constant speed of 1800 rpm. Three proportions of DMC are taken which are 10, 20, and 30% by volume and blended with pure diesel. Biogas flow rates taken are 12 lpm and 16 lpm. An experimental study was performed and it is found that a maximum of 3% drop in brake thermal efficiency at high DMC proportions but at low biogas flow rates, the efficiency increased up to 2.7%. NO_x emissions were observed to be low on addition of DMC and further decreased at high biogas flow rates. The maximum reduction of 57.5% is observed when compared to diesel-only mode. CO emissions increased upto 28% at high DMC fractions. In combustion characteristics, the Maximum Heat Release Rate (MHRR) decreased at high DMC fractions and high biogas flow rates but decreased, at high loads. The maximum cylinder pressure also decreased at high DMC fractions and at high biogas flow rates. The period of combustion increases when DMC fraction is increased.

In today’s world with the technological advancements, all that has been considered as slags and waste can be utilized to its maximum therefore attaining sustainability. Thermoelectric devices are now being used in various applications including cooling and heating processes in electronics and automobiles. The choice of materials for these thermoelectric devices are essential in order to determine the parameters such as temperature gradient, thermo emf and total heat dissipated with the help of Seebeck, Peltier and Thomson co-efficients. The elements for the thermoelectric device are arranged by their thermo emf produced in the thermoelectric series. This has been taken into account for the selection of materials for the heating device, analyzed in this article. In certain cold countries, temperature can drop below 10°C, which is very much near its cloud point and pour point of petroleum fuels. Thermoelectric devices will thereby come to use in these places to maintain the temperature above the cloud point of the fuel. This study also focuses on another application of waste heat recovery in automobile engines to produce thermo emf, which can be utilized for small scale electronics in automobiles. In this study, materials are analyzed for the previously mentioned applications.

In this work both experimental and numerical analysis are carried out to investigate the effect of solar radiation on the cabin air temperature of Maruti Suzuki Celerio car parked for 90 min under solar load condition. The experimental and numerical analysis encompasses on temperature increment of air at various locations inside the vehicle cabin. The effect of 90 min exposure to the environment is simulated with the help of Discrete Ordinance (DO) and Surface to Surface (S2S) radiation models using ANSYS FLUENT 18.2. Moreover, the impacts of using different turbulence model on the accuracy of the simulation results and the comparison between steady state and transient state simulation results have also been studied. The results of the simulation are compared with the experimental data to contrast the model. The absolute average deviation in temperature predicted by DO and S2S model from the experimental data are 10.07 and 10.01%, respectively. In this work both experimental and numerical analysis are carried out to investigate the effect of solar radiation on the cabin air temperature of Maruti Suzuki Celerio car parked for 90 min under solar load condition. The experimental and numerical analysis encompasses on temperature increment of air at various locations inside the vehicle cabin. The effect of 90 min exposure to the environment is simulated with the help of Discrete Ordinance (DO) and Surface to Surface (S2S) radiation models using ANSYS FLUENT 18.2. Moreover, the impacts of using different turbulence model on the accuracy of the simulation results and the comparison between steady state and transient state simulation results have also been studied. The results of the simulation are compared with the experimental data to contrast the model. The absolute average deviation in temperature predicted by DO and S2S model from the experimental data are 10.07 and 10.01%, respectively. First published in 1988, International Journal of Engineering (IJE) is multidisciplinary science journal published in three quarterly transactions.