Abstract-This paper discusses a detailed study on the performance of a SI engine fuelled with camphor-ethanol-petrol blends. In this study, a mixture consists of camphor and ethanol in weight percentage (20:80) was blended with petrol in three different ratios: 10%, 20% and 30%. A performance test was conducted in the SI engine at constant speed with varying torque using an eddy current dynamometer in order to evaluate the performance between the blended fuel and the sole fuel, such as brake power, specific fuel consumption, brake thermal efficiency and volumetric efficiency, among others. The study also includes viscosity measurements from a redwood viscometer, Calorific value measurements from a bomb calorimeter, density calculations and exhaust emission tests in a four gas analyser for both blended fuels as well as for pure petrol. It is inferred from the study that lesser specific fuel consumption, less emissions due to complete combustion of air fuel mixture and maximum volumetric efficiency were achieved in the blended fuel that results in efficient working of the spark ignition engine with less pollution. The main objective of this study is to increase the performance of SI engines, to reduce the emission rate and minimize the specific fuel consumption with the blended fuel to make the planet greener.

This paper examines failure of helical gear in speed increasing gearbox used in the wind turbine generator (WTG). In addition, an attempt has been made to get suitable gear micro-geometry such as pressure angle and tip relief to minimize the gear failure in the wind turbines. As the gear trains in the wind turbine gearbox is prearranged with higher speed ratio and the gearboxes experience shock load due to atmospheric turbulence, gust wind speed, non-synchronization of pitching, frequent grid drops and failure of braking, the gear failure occurs either in the intermediate or high speed stage pinion. KISS soft gear calculation software was used to determine the gear specifications and analysis is carried out in ANSYS software version.11.0 for the existing and the proposed gear to evaluate the performance of bending stress tooth deflection and stiffness. The main objective of this research study is to propose suitable gear micro-geometry that is tip relief and pressure angle blend for increasing tooth strength of the helical gear used in the wind turbine for trouble free operation.Electronic supplementary materialThe online version of this article (doi:10.1186/2193-1801-3-746) contains supplementary material, which is available to authorized users.

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Introduction. The high voltage gain DC-DC converters are increasingly used in many power electronics application systems, due to their benefits of increased voltage output, reduced noise contents, uninterrupted power supply, and ensured system reliability. Most of the existing works are highly concentrated on developing the high voltage DC-DC converter and controller topologies for goal improving the steady state response of brushless DC motor driving system and also obtain the regulated voltage with increased power density and reduced harmonics, the LLC resonant DC-DC converter is implemented with the silicon carbide MOSFET switching devices Problem. Yet, it facing the major problems of increased switching loss, conduction loss, error outputs, time consumption, and reduced efficiency. Also the existing works are mainly concentrating on improving the voltage gain, regulation, and operating performance of the power system with reduced loss of factors by using the different types of converters and controlling techniques. The goal of this work is to obtain the improved voltage gain output with reduced loss factors and harmonic distortions. Method. Because, this type of converter has the ability to generate the high gain DC output voltage fed to the brushless DC motor with reduced harmonics and loss factors. Also, the nonlinear adaptive sliding controller is implemented to generate the controlling pulses for triggering the switching components properly. For this operation, the best gain parameters are selected based on the duty cycle, feedback DC voltage and current, and gain of silicon carbide MOSFET. By using this, the controlling signals are generated and given to the converter, which helps to control the brushless DC motor with steady state error. Practical value. The simulation results of the proposed LLC silicon carbide MOSFET incorporated with nonlinear adaptive sliding controller controlling scheme are validated and compared by using various evaluation indicators.

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