Refine Your Search

Topic

Search Results

Viewing 1 to 9 of 9
Technical Paper

Two Stroke Direct Injection Jet Ignition Engines for Unmanned Aerial Vehicles

2015-09-15
2015-01-2424
Unmanned Aerial Vehicles (UAV) require simple and reliable engines of high power to weight ratio. Wankel and two stroke engines offer many advantages over four stroke engines. A two stroke engines featuring crank case scavenging, precise oiling, direct injection and jet ignition is analyzed here by using CAD, CFD and CAE tools. Results of simulations of engine performances are shown in details. The CFD analysis is used to study fuel injection, mixing and combustion. The CAE model then returns the engine performances over the full range of loads and speeds with the combustion parameters given as an input. The use of asymmetric rather than symmetric port timing and supercharging scavenging is finally suggested as the best avenue to further improve power density and fuel conversion efficiency.
Technical Paper

Investigating the Potential of Waste Heat Recovery as a Pathway for Heavy-Duty Exhaust Aftertreatment Thermal Management

2015-04-14
2015-01-1606
Heavy-duty diesel (HDD) engines are the primary propulsion source for most heavy-duty vehicle freight movement and have been equipped with an array of aftertreatment devices to comply with more stringent emissions regulations. In light of concerns about the transportation sector's influence on climate change, legislators are introducing requirements calling for significant reductions in fuel consumption and thereby, greenhouse gas (GHG) emission over the coming decades. Advanced engine concepts and technologies will be needed to boost engine efficiencies. However, increasing the engine's efficiency may result in a reduction in thermal energy of the exhaust gas, thus contributing to lower exhaust temperature, potentially affecting aftertreatment activity, and consequently rate of regulated pollutants. This study investigates the possible utilization of waste heat recovered from a HDD engine as a means to offset fuel penalty incurred during thermal management of SCR system.
Technical Paper

A Naturally Aspirated Four Stroke Racing Engine with One Intake and One Exhaust Horizontal Rotary Valve per Cylinder and Central Direct Injection and Ignition by Spark or Jet

2015-03-10
2015-01-0006
The paper discusses the benefits of a four stroke engine having one intake and one exhaust rotary valve. The rotary valve has a speed of rotation half the crankshaft and defines an open passage that may permit up to extremely sharp opening or closing and very large gas exchange areas. The dual rotary valve design is applied to a racing engine naturally aspirated V-four engine of 1000cc displacement, gasoline fuelled with central direct injection and spark ignition. The engine is then modeled by using a 1D engine & gas dynamics simulation software package to assess the potentials of the solution. The improved design produces much larger power densities than the version of the engines with traditional poppet valves revving at higher speeds, with reduced frictional losses, and with larger gas exchange areas while also improving the fuel conversion efficiency thanks to the sharpness of opening or closing events.
Technical Paper

Recommendation of Experimental Setup and use of Standardized Electrohydrodynamic Dimensionless Parameters for Optimization of a Dielectric Barrier Discharge Flow Control Device

2014-09-16
2014-01-2101
The high demand for traditional air traffic as well as increased use of unmanned aerial systems (UAS) has resulted in researchers examining alternative technologies which would result in safer, more reliable, and better performing aircraft. Active methods of aerodynamic flow control may be the most promising approach to this problem. Research in the area of aerodynamic control is transitioning from traditional mechanical flow control devices to, among other methods, plasma actuators. Plasma actuators offer an inexpensive and energy efficient method of flow control. Dielectric Barrier Discharge (DBD), one of the most widely studied forms of plasma actuation, employs an electrohydrodynamic (EHD) device which uses dominant electric fields for actuation. Unlike traditional flow control methods, a DBD device operates without moving components or mass injection methods.
Technical Paper

The Influence of High Reactivity Fuel Properties on Reactivity Controlled Compression Ignition Combustion

2017-09-04
2017-24-0080
Reactivity controlled compression ignition (RCCI) is a form of dual-fuel combustion that exploits the reactivity difference between two fuels to control combustion phasing. This combustion approach limits the formation of oxides of nitrogen (NOX) and soot while retaining high thermal efficiency. The research presented herein was performed to determine the influences that high reactivity (diesel) fuel properties have on RCCI combustion characteristics, exhaust emissions, fuel efficiency, and the operable load range. A 4-cylinder, 1.9 liter, light-duty compression-ignition (CI) engine was converted to run on diesel fuel (high reactivity fuel) and compressed natural gas (CNG) (low reactivity fuel). The engine was operated at 2100 revolutions per minute (RPM), and at two different loads, 3.6 bar brake mean effective pressure (BMEP) and 6 bar BMEP.
Technical Paper

Low Temperature Combustion with Thermo-Chemical Recuperation

2007-10-29
2007-01-4074
The key to overcoming Low Temperature Combustion (LTC) load range limitations is based on suitable control over the thermo-chemical properties of the in-cylinder charge. The proposed alternative to achieve the required control of LTC is the use of two separate fuel streams to regulate timing and heat release at specific operational points, where the secondary fuel, with different autoignition characteristics, is a reformed product of the primary fuel in the tank. It is proposed in this paper that the secondary fuel is produced using Thermo-Chemical Recuperation (TCR) with steam/fuel reforming. The steam/fuel mixture is heated by sensible heat from the engine exhaust gases in the recuperative reformer, where the original hydrocarbon reacts with water to form a hydrogen rich gas mixture. An equilibrium model developed by Gas Technology Institute (GTI) for n-heptane steam reforming was applied to estimate reformed fuel composition at different reforming temperatures.
Technical Paper

Technological Evaluation of Fuel Efficiency Improvement Concepts to Meet Future Regulatory Requirements in the North American Market

2002-10-21
2002-01-2809
As fuel economy and emissions regulations increase in stringence, automakers face ever increasing difficulty in meeting government imposed standards. In this paper a study of fuel economy improving techniques used to meet these regulations, notably Corporate Average Fuel Economy (CAFE), and the upper limit on the effectiveness of these techniques is presented. The effects of external vehicle improvements, such as lightweighting, rolling resistance and aerodynamic improvements were investigated to illustrate the limitations of these methods to dramatically improve overall vehicle efficiency. Engine efficiency improvements, including the effects of compression ignition (unthrottled) versus spark ignition (throttled) engine types were examined. Other engine efficiency areas that were investigated were the implementation of cylinder deactivation and gasoline direct injection engines.
Journal Article

Diesel Exhaust Aftertreatment with Scrubber Process: NOx Destruction

2012-05-15
2011-01-2440
Oxides of nitrogen (NOx) emissions, produced by engines that burn fuels with atmospheric air, are known to cause negative health and environmental effects. Increasingly stringent emissions regulations for marine engines have caused newer engines to be developed with inherent NOx reduction technologies. Older marine engines typically have a useful life of over 20 years and produce a disproportionate amount of NOx emissions when compared with their newer counterparts. Wet scrubbing as an aftertreatment method for emissions reduction was applied to ocean-going marine vessels for the reduction of sulfur oxides (SOx) and particulate matter (PM) emissions. The gaseous absorption process was explored in the laboratory as an option for reducing NOx emissions from older diesel engines of harbor craft operating in ports of Houston and Galveston. A scrubber system was designed, constructed, and evaluated to provide the basis for a real-world design.
Journal Article

Energy Conservation through Productivity Enhancement in Manufacturing Facilities

2008-04-14
2008-01-1164
The goal of this research work is to explore the energy savings that may result from productivity improvement recommendations. The productivity improvement recommendations on setup time reduction and finished goods inventory reduction were taken from Industrial Assessment Center (IAC-WVU) and Industries of the Future (IOF-WVU) databases at West Virginia University (WVU) and analyzed to evaluate the corresponding energy savings. A simulation analysis was performed to compare the peak energy demands (kW) in the present and proposed scenarios for the setup time reduction recommendation. It was found that productivity improvement recommendations can result in significant energy savings (2% to 4%).
X