1. 1. A PRESENTATION ON TRANSONIC ENGINE Presented To: Presented By: Chhabile Sharan Bansal Assistant Professor 11EVVME018 Department of Mechanical Engg. B.Tech IV Year VIII Sem.
2. 2. CONTENTS Introduction Transonic combustion Transonic engine principle Transonic combustion technology Ignition timing the key Common rail system Supercritical Fuel and injection system The comparison of liquid and supercritical fuel Taking aim at gas guzzlers Benefits of TSCi engine Pollution chart conclusion
3. 3. Spark ignition gasoline engine efficiency is limited by a number of factors; these include the pumping losses that result from throttling for load control, spark ignition and the slow burn rates that result in poor combustion phasing and a compression ratio limited by detonation of fuel. A new combustion process has been developed based on the patented concept of injection-ignition known as Transonic Combustion or TSCi; this combustion process is based on the direct injection of fuel into the cylinder as a supercritical fluid. Supercritical fuel achieves rapid mixing with the contents of the cylinder and after a short delay period spontaneous ignition occurs at multiple locations. Multiple ignition sites and rapid combustion combine to result in high rates of heat release and high cycle efficiency. The injection-ignition process is independent from the overall air/fuel ratio contained in the cylinder and thus allows the engine to operate un-throttled. INTRODUCTION
4. 4. TRANSONIC COMBUSTION The stratified nature of the charge under part load conditions reduces heat loss to the surrounding surfaces, resulting in further efficiency improvements. The short combustion delay angles allow for the injection timing to be such that the ignition and combustion events take place after TDC. This late injection timing results in a fundamental advantage in that all work resulting from heat release produces positive work on the piston. Other advantages are the elimination of droplet burning and increased combustion stability that results from multiple ignition sources. Engine test results are presented over a range of speed, load and operating conditions to show fuel consumption, emission and combustion characteristics from initial injector and combustion system designs. The results are correlated with thermo-dynamic modelling and comparisons are made with contemporary engines.
5. 5. TRANSONIC ENGINE PRINCIPLE Transonic engine is based on the principle of the fuel injection. In transonic engine ignition system is removed and redesigned the fuel injection. fundamentally new fuel injection technologies that enable conventional internal combustion automotive engines to run at ultra-high efficiency. By operating high compression engines that incorporate precise ignition timing with carefully minimized waste heat generation, Transonic Combustion may have a transformational technology-one that can achieve double efficiency compared to current gasoline powered vehicles in urban driving. In turn, the companys products also may significantly reduce fossil fuel consumption and GHG emissions.
6. 6. THE TRANSONIC COMBUSTION TECHNOLOGY The Transonic Technology provides a heated catalysed fuel injector for dispensing fuel predominately or substantially, exclusively during the power stroke of an IC engine. This injector lightly oxidizes the fuel in a supercritical vapour phase via externally applied heat from an electrical heater or other means. The injector may operate on a wide range of liquid fuels including gasoline, diesel and various bio fuels. The injector fire at room pressure and up to the practical compression limit of IC engines. Since the injector may operate independent of spark ignition or compression ignition, its operation is referred to herein as injection-ignition.
7. 7. To minimise friction losses, the transonic engineers have steadily reduced the compression of their test engines to between 20:1 and 16:1, with the possibility of 13:1 for gasoline engines. There may be some advantage to going a little higher, but the developers had tried to keep the fuel system within the range that OEMs understand. The fundamental problem is that on average about 15% of the energy from the gasoline you put into your tank gets used to move your car down the road . The rest of the energy is lost to engine and driveline inefficiencies and idling. Normal engines runs with rich air to fuel ratios, which also results in fuel being trapped in the crevice as well as partially combusting near the cylinder walls, this energy loss is the core of automotive inefficiency
8. 8. IGNITION TIMING THE KEY SC fluids have unique properties. For a start, their density is midway between those of a liquid and gas, about half to 60% that of the liquid. They also feature the molecular diffusion rates of a gas and so can dissolve substances that are usually tough to place in solution. SC fluid has a very low surface tension. This enables quicker mixing, and it exhibits catalytic activity that is two to three orders of magnitude faster than the purely liquid form of the substance. If we eliminates the time it takes to vaporize fuel and the heat lost with contact with the cylinder walls, we could improve the base efficiency of an engine. It is been figured that by changing the ignition delay so the fuel ignited in that area, the flame can be kept away from contact with the walls, which take heat out the engine.
9. 9. COMMON RAIL SYSTEM In this system a high pressure pump supplies fuel to fuel header as shown. the high pressure in the header forces the fuel to each of the nozzles located in the cylinders. At the proper time a mechanically operated (by means of push rod and rocker arm) valve allows the fuel to enter the cylinder through nozzle.
10. 10. SUPERCRITICAL FUELAND INJECTION SYSTEM A comparison of standard direct injection of liquid fuel and transonics novel supercritical injection process (as viewed through an optical engine fitted with a quartz window) shows that the new TSCi fuel delivery system does not create fuel droplets.
11. 11. THE COMPARISON OF LIQUID AND SUPERCRITICAL FLUID Throughout the history of internal combustion engine, engineers have boosted cylinder compression to extract more mechanical energy from a given fuel-air charge. The extra pressure enhances the mixing and vaporization of the injected droplets before burning.
12. 12. When people think about reducing gasoline consumption, alternative-fuel and hybrid cars usually come to mind. A superefficient fuel injector designed to integrate easily into conventional cars. Unlike standard fuel injectors, the TSCi injector pressurizes and heats gasoline to 400 degrees Celsius, bringing it to a supercritical state that is partway between liquid and gas. When the substance enters the combustion chamber, it combusts without a spark and mixes with air quickly, allowing it to burn more efficiently than the liquid droplets produced by standard injectors. A Transonic test car the size and weight of a Toyota Prius achieved 64 miles per gallon at highway speeds, compared with the 48 mpg highway rating on the Prius. Transonic is working with three major automakers and expects the first TSCi-equipped vehicles to hit the market in 2016. Multi Tasker Transonic is testing its 10.5-inch-long injector with ethanol, biodiesel, and vegetable oil, in addition to gasoline. TAKING AIM AT GAS GUZZLERS
13. 13. BENEFITS OF TSCi SYSTEM Improved fuel efficiency Lower green house emission Multi-fuel compatible Economical OEM Powertrain integration Near term adoption Global automotive industrial sustainability Energy independence
14. 14. POLLUTION CHART
15. 15. CONCLUSION If it works as promised, the transonic combustion engine technology would improve fuel economy by far more than other options, some of which can improve efficiency on the order of 20 percent. It is expected to cost about as much as high end fuel injection systems currently on the market.
16. 16. THANK YOU