G. Sudarshan

Bio: G. Sudarshan is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Diesel fuel & Spray characteristics. The author has an hindex of 1, co-authored 1 publications receiving 4 citations.

Effects of autooxidation on the fuel spray characteristics of Karanja biodiesel

Abstract: A significant obstacle to utilize biodiesel fuel for automotive engine applications is its poor oxidative stability. In the present work, oxidation and spray characteristics of Karanja biodiesel stored for one year are studied. The fuel physical properties that influence the spray characteristics, viz. density, kinematic viscosity, and surface tension, are increased by 0.38%, 12.74%, and 3.95%, respectively, after a one-year storage period. The macroscopic spray characteristics of fresh and aged Karanja biodiesels are compared with that of diesel. The spray penetration length, spray cone angle, and the projected spray area are measured at chamber pressures of 20, 30, and 40 bar and injection pressures of 300, 600, and 900 bar. The results showed reduced mass flow rate at lower injection pressures with fresh and aged biodiesels than diesel. At 300 bar injection pressure, spray penetration length is longer with diesel during the initial injection period, but later the spray slows down. There are no appreciable differences in the spray penetration length and the spray cone angle between diesel, fresh, and aged biodiesels at all the injection pressures. The projected spray area is higher for diesel than biodiesels indicating a denser spray with biodiesels. The study concludes that although biodiesel's long-term storage results in variations in physical and chemical properties, there are no significant variations in the macroscopic spray characteristics. Analysis of atomization characteristics of fresh and aged biodiesels also revealed similar results.

Effect of Temperature on Tribological Propertiesof Palm Biodiesel

Abstract: Biodiesel, as an alternative fuel is steadily gaining attention to replace petroleum diesel partially or completely. The tribological performance of biodiesel is crucial for its application in automobiles. In the present study, effect of temperature on the tribological performance of palm biodiesel was investigated by using four ball wear machine. Tests were conducted at temperatures 30, 45, 60 and 75°C, under a normal load of 40kg for 1h at speed 1200rpm. For each temperature, the tribological properties of petroleum diesel (B0) and three biodiesel blends like B10, B20, B50 were investigated and compared. During the wear test, frictional torque was recorded on line. Wear scars in tested ball were investigated by optical microscopy. Results show that friction and wear increase with increasing temperature.

Spray characteristics of biofuels for advance combustion engines

Abstract: This study investigates spray characteristics, flashing and non-flashing, of unsaturated neem biodiesel (BD), biodiesel-ethanol (BDE50) blend, and diesel for application in advanced combustion engines. Fuel properties, injection pressure, nozzle geometry, and the surrounding ambient gas conditions govern the spray breakup and air-fuel mixing. The spray characteristics of fuel is studied at various injection pressure and ambient gas densities using the high-speed shadowgraphy technique. BDE50 shows improved spray dispersion with distinct tree-shaped spray morphology at ambient density of 1.14 kg/m3 and injection pressure of 50 MPa. Theoretical analysis confirms occurrence of cavitation due to high volatile component (ethanol) in biofuel mixture and throttling conditions. At high ambient gas density and injection pressure, diesel and BDE50 exhibit high spray cone angle. Neem biodiesel maintains high tip penetration and low cone angle due to poor atomization. The study recommends use of BDE50 blend for achieving improved mixture formation in engines.

Recent Advances in Fuel Additives and Their Spray Characteristics for Diesel-Based Blends

Abstract: The spray characteristics play a crucial role in determining the performance and emissions of compression ignition (CI) engines at the pre-combustion stage. With the advent of many types of alternative fuels and their blends with diesel, it is necessary to investigate the effect of fuel properties and various injection conditions to determine the penetration length, spray cone angle and spray area for a viable fuel with similar or better dispersion characteristics to diesel. Hence, this study reviews and summarizes the spray visualization techniques, along with in depth analysis of macroscopic spray properties of various fuel blends with diesel. It was found that higher injection pressures typically led to higher penetration lengths, better atomization with reduced Sauter mean diameter. Liquid properties such as viscosity, surface tension, and evaporation as well as structural properties play a crucial role in spray formation in fuel blends with various types of alcohols, ethers, biodiesel, aliphatic, aromatic, as well as nanoparticle additives. This review compares these fuel additives and their types to present a comparative study with diesel to determine the ideal conditions with minimal changes to the engine for replacing diesel with a sustainable fuel consisting of better combustion efficiency due to its enhanced spray characteristics.