Cantilever beams with piezoelectric coating are the most widely used form of strain-driven energy harvesting. Almost all prior research on cantilever beam shapes aimed at enhancing energy output accounts for beams fully coated with piezoelectric materials. While a larger coating area, up to a certain limit, can enhance energy output, it also escalates the cost of the structure, as piezoelectric materials are very expensive. Output power density over the length of the beam/piezoelectric material varies significantly. Hence, a partially coated beam with an optimized positioning of piezoelectric material can not only cut the cost of the system but also warrant a higher output power density. On the other hand, optimizing the base beam shape always remains one of the top approaches to increasing the power output. As such, this work aims to select a cantilever beam design by investigating a wide variety of cantilever beam shapes while the beam is partially coated with the piezoelectric material to maximize the power output capacity of the harvester. In the first part of the study, an efficient size of the piezoelectric material and its placement in the host beam are selected based on the power capacity of the system. Next, the selected effective size and placement of the piezoelectric material is implemented in a wide range of cantilever beam shapes (e.g., trapezoidal, triangular, V-cut, concave, and convex) to select a host beam design for maximizing the output power density. To ascertain a comparable argument, the surface area, volume, and mass of all the considered beam shapes are kept consistent, as these parameters influence the power output of the harvester. The geometry of each shape is systematically varied to understand the effect of geometric configuration on the output power density. Additionally, an analysis is conducted to validate that the findings/selection of this study are independent of the thickness of the host beam or piezoelectric material.

Due to the depletion of Diesel fuel and higher cost, it is desirable to find alternative fuel with lower cost and better combustion and emission characteristics. As, gaseous fuel is cheaper than liquid fuel, one of the effective solutions to obtain better engine performance is replacing a portion of liquid fuel by gaseous fuel in CI engine which is called dual fuel CI engine. In dual fuel engine, main gaseous fuel is provided through intake manifold by premixing with air and the mixture is ignited by injecting liquid pilot fuel at near the end of the compression stroke. The process is cost effective as well as the engine obtain higher thermal efficiency and lower soot, CO, UHC emission. But NOx emission is increased in CI engine with dual fuel mode which adversely affected the human health and pollute the environment. By applying Exhaust Gas Recirculation (EGR), NOx emission and knocking of the engine can be reduced. In this numerical simulation, the effect of EGR on combustion and emission performance of dual fuel CI is investigated through ANSYS Forte 18.1. In this study, gasoline is considered as main gaseous fuel and diesel is considered as liquid pilot fuel. Effect of EGR on various engine parameters such as in-cylinder pressure, temperature, heat release rate, ignition delay, combustion duration, NOx, CO and UHC emission is investigated. It is seen that, in-cylinder peak pressure is reduced to 50.65% and in-cylinder maximum temperature is reduced to 60.19% for the addition of 40% EGR. NOx emission is reduced to 57.19% for the addition of 10% EGR, 21.32% for 20% EGR, 1.57% for 30% EGR and 0.014% for 40% EGR.

Higher production cost of anhydrous ethanol associated with distillation and dehydration process could be reduced through the direct use of wet/hydrous ethanol in engine applications. In this study, both experimental investigation and numerical analysis were carried out to quantify the effect of water content on laser ignition characteristics of premixed charge of wet ethanol with different water concentration and over a range of equivalence ratios. Combustion of wet ethanol was initiated through laser-induced breakdown from a Q-switched Nd:YAG laser. A high-speed camera is used to visualize the ignition event and flame propagation. Results demonstrated that, presence of water in ethanol up to 20% by volume accelerated the initial combustion reactions and led to faster burning. Adverse effects of elevated water concentration in ethanol at and beyond 30% (v/v), are more pronounced in fuel lean combustion region compared with fuel rich combustion. Laser-induced breakdown spectroscopic (LIBS) measurements revealed that, plasma temperature slightly increased with added water in ethanol up to 20% (v/v) as water in ethanol results in enhanced ionization of the gas mixture during laser breakdown, which leads to more intense absorption of laser energy. Therefore, this study demonstrates the potential of direct use of wet ethanol as an attractive fuel for IC engine.