Refine Your Search




Search Results

Journal Article

Enhancement of Diesel Soot Combustion with Oxygen on Particulate Filters After Injection of Dicyclopentadienyl Iron (Ferrocene) in the Exhaust Pipe

For the regeneration of diesel particulate filters with oxygen, temperatures above 550°C are normally required. The increase of the exhaust gas temperature to temperatures above 500°C demands a large amount of energy, so that strategies to reduce the regeneration temperature have to be considered. One option is the injection of a catalyst, which reduces the required regeneration temperature. Hence, a system was developed at HJS Emission Technology GmbH to inject catalyst-precursor into the exhaust gas pipe, whereby the catalysts are generated due to decomposition of the precursor in the hot exhaust gas. A technique based on the calculation of apparent activation energies was developed to characterize the soot combustion on the filter. In the first step metal oxide catalysts, like cerium(IV)oxide, manganese-oxide and iron(III)oxide were investigated after injection of their nitrate precursors dissolved in water.
Journal Article

Application of a Split Lubrication Gasoline Engine to the Screening and Understanding of Friction Modifier Behaviour

A series of viscous and surface friction modifier additives has been studied in a modified SI engine with separable valve train lubrication. From the results, it has been possible to classify the hydrodynamic or boundary lubrication nature of the observed effects for a series of lubricant additives. It is shown that the frictional benefit of a given additive depends not only on the engine operating condition but also on the engine components on which it is acting. For some additives a fuel economy benefit can switch to a disbenefit as operating regime changes and a different aspect of the additive properties becomes important. Such observations are rationalised in the context of conventional lubrication theory.
Journal Article

Smart, In Situ, Wide Range Pressure Sensor for Advanced Engine Controls

Air Force Research Laboratory (AFRL) is pursuing development of advanced, distributed, intelligent, adaptive engine controls and engine health monitoring systems. The goals this pursuit are enhancing engine performance, safety, affordability, operability, and reliability while reducing obsolescence risk. The development of smart, high-bandwidth, high-temperature-operable, wide-range, pressure/temperature multi-sensors, which addresses these goals, is discussed. The resulting sensors and packaging can be manufactured at low cost and operate in corrosive environments, while measuring temperatures up to 2,552 °F (1,400 °C) with simultaneous pressure measurements up to 1,000 psi (68 atm). Such a sensor suite provides unprecedented monitoring of propulsion, energy generation, and industrial systems. The multi-sensor approach reduces control system weight and wiring complexity, design time, and cost, while increasing accuracy and fault tolerance.
Journal Article

Fleet Vehicle Idling - Are Supplemental Hybrid Idling Reduction Systems the Answer?

Environmental concerns and rising fuel costs are driving Ontario's municipalities and fleet operators to consider alternative vehicle technologies. Elevated fuel consumption and air emissions are attributed to the unique operations of fleet vehicles and in particular, during idling. While drivers of passenger vehicles may have the option of simply not idling, fleet and emergency vehicle operators, may need to keep the vehicle operating to supply power to critical onboard equipment. These demands may be exacerbated during seasonal, temperature extremes. However, prolonged idling can impose significant environmental and economic burdens. Hybrid vehicles have yet to be utilized widely by Ontario's fleets, but there are other approaches to reduce emissions, including alternative “green” technologies to operate in-vehicle equipment and maintain fleet vehicle capabilities instead of idling.
Journal Article

An Aerosolization Method for Characterizing Particle Contaminants in Diesel Fuel

Diesel fuel injection systems are operating at increasingly higher pressure (up to 250 MPa) with smaller clearances, making them more sensitive to diesel fuel contaminants. Most liquid particle counters have difficulty detecting particles <4 μm in diameter and are unable to distinguish between solid and semi-solid materials. The low conductivity of diesel fuel limits the use of the Coulter counter. This raises the need for a new method to characterize small (<4 μm) fuel contaminants. We propose and evaluate an aerosolization method for characterizing solid particulate matter in diesel fuel that can detect particles as small as 0.5 μm. The particle sizing and concentration performance of the method were calibrated and validated by the use of seed particles added to filtered diesel fuel. A size dependent correction method was developed to account for the preferential atomization and subsequent aerosol conditioning processes to obtain the liquid-borne particle concentration.
Journal Article

Design Analysis for Origami-Based Folded Sheet Metal Parts

1 The manufacturing of Origami based sheet metal products is a promising technology, mostly in terms of reducing the tooling and process complexity. This procedure can also be called fold forming, as it depends on exclusively shaping the required geometry via sequence of bends. However, the design analysis and modeling of folded sheet metal products are not fully mature, especially in terms of determining the best approach for transferring the analysis from a three-dimensional (3D) to a two-dimensional (2D) context. This manuscript discusses the extension of the Origami technique to the fold forming of sheet metal products represented in modeling approach and design considerations for the topological variations, the geometrical validity, and the variance of stress-based performance. This paper also details the optimization metrics that were developed to reflect the design and manufacturing differences among the possible topological and geometrical options for a single part design.
Journal Article

Description and Performance Analysis of a Flow Test Rig to Simulate Altitude Pressure Variation for Internal Combustion Engines Testing

Calibration of internal combustion engines at different altitudes, above or below sea level, is important to improve engine performance and to reduce fuel consumption and emissions in these conditions. In this work, a flow test rig that reproduces altitude pressure variation is presented. The system stands out by its altitude range, compactness, portability and easy control. It is based on the use of turbomachinery to provide the target pressure to the engine intake and exhaust lines. The core of the system is composed of a variable geometry turbine (VGT) with a waste-gate (WG) and a mechanical compressor. Given a set of turbomachinery systems, the operation pressure and the air mass flow are controlled by the speed of the mechanical compressor and the VGT and WG position. A simple modification in the installation setup makes possible to change the operating mode from vacuum to overpressure. So that simulating altitude increase or decrease with the same flow test rig components.
Journal Article

Design, Modeling, and Evaluation of a Cost Effective Particulate Control System

A cost effective, portable particulate control system was developed, built, and evaluated at the University of Louisiana at Lafayette. Prototype of the presented system was developed for experimental assessment and its computational model was also created for CFD simulation. The experimental and computer simulation results showed that the developed system could efficiently and safely remove and dispose accumulated particulate matter (in the size range of 5 ∼ 1000 μm), and be tolerant to the abrasive properties that the particulate matter may have. The developed particulate control system as well as the applied technology can be further optimized and extended to be applied in aerospace and space engineering to remove suspended particles out from the closed cabinet of aircrafts or spacecrafts. The outcome of this project will also impact other commercial sectors and industries.
Journal Article

Exergetic Investigation of a Turboshaft Helicopter Engine Related to Engine Power

Abstract Turboshaft engines, one of the classifications of the helicopters, combine the core engine and fan and consume fossil fuels. Using of fossil fuel causes global warming and environmental pollution, such as ecological, human health. To improve helicopter capability, energy is the first point of improvement. High-energy efficient helicopter engines help decrease the environmental damage. Exergy should be applied to the system to determine the maximum available energy. In this study, energy analysis and exergy analysis have been applied to a turboshaft helicopter engine. According to the result of this study, the maximum energy and exergy efficiencies are found to be 21.99% and 15.87%, respectively, at 1500 Shaft Horsepower (SHP). It is seen that the efficiencies increase with the increase of the engine power. Besides, exergy destructions and exergy loss values are presented by calculating different powers.