Refine Your Search




Search Results

Technical Paper

A Canister Fuel Pump for General Aviation Aircraft

A new family of canister-type fuel pumps for use on both rotary and fixed-wing aircraft in general aviation use will be described. The pump, which features a wet-brush DC motor, offers advantages on aircraft where ease of maintenance and minimum downtime is very important. Major features of the new design, pump performance, and maintenance cost savings will be discussed.
Technical Paper

A Carburetor Icing Field Test: Procedures and Results

The test procedures and some of the results obtained in a carburetor icing field test at Vancouver, British Columbia, during the Winter of 1962-1963 are described. One hundred twenty-nine cars were involved in the test which lasted approximately four months. A total of about 15,000 test runs was made. Fifty percent of the cars stalled at much higher rates under weather conditions conducive to carburetor icing than under other conditions. Thus, carburetor icing was found to be a significant field problem even with effective antiicing additives present in the gasoline. There was much variation among car makes in their tendencies to stall, indicating the possibilities of design improvements in reducing the problem. There was an indication that recent model cars stalled at lower rates than earlier models, showing that some improvement has been made.
Technical Paper

A Catalytic NOX After-Treatment System for Heavy-Duty Trucks Using Diesel Fuel as Reducing Agent

An advanced catalytic exhaust after-treatment system addresses the problem of NOX emissions from heavy-duty diesel trucks, relying on real-time catalyst modelling. The system consists of de-NOX catalysts, a device for injection of a reducing agent (diesel fuel) upstream the catalysts, and computer programmes to control the injection of the reducing agent and to model the engine and catalysts in real time. Experiments with 5 different air-assisted injectors were performed to determine the effect of injector design on the distribution of the injected diesel in the exhaust gas stream. A two-injector set-up was investigated to determine whether system efficiency could be increased without increasing the amount of catalyst or the amount of reducing agent necessary for the desired outcome. The results were verified by performing European standard transient cycle tests as well as stationary tests.
Technical Paper

A Characteristic Study of Electronic In-line Pump System for Diesel Engines

A new fuel injection equipment, the Electronic In-line Pump (EIP) system has been developed in this paper, in order to meet China's PHASE III emission regulation. A numerical model of the EIP system was built in the AMESim environment for the purpose of creating a design tool for engine application and system optimization. The model was used to predict key injection characteristics, i.e. injection pressure, injection rate, injection duration at different operating conditions, etc. To validate these predictions, experimental tests were conducted at the same model conditions. The results are quite encouraging, and in agreement with model predictions. Additional experiments were conducted to study the injection characteristics of the EIP system. These results show that the injection pressure and injection quantity are insensitive to injection timing variation due to the design of constant velocity cam profile.
Technical Paper

A Chassis Dynamometer Study of the Effects of AGO Detergent and Ignition Improver on Vehicle Fuel Consumption

The benefits of diesel fuel additives have been demonstrated in a broad range of performance and operational areas, from the refinery, through storage and distribution, to fuel dispensing and vehicle operation. The customer is certainly aware of their effects on fuel performance in many of these respects, such as cold-weather operation, ease of starting, foaming, odour, etc. An area of particular interest in customer perception, however, is fuel economy. Excluding the use of after-market fuel-treatment devices, it is claimed that additives of different types can improve fuel economy, for example by improving combustion, by maintaining injection equipment in optimum condition, or by reducing engine frictional losses.
Journal Article

A Chemical and Morphological Study of Diesel Injector Nozzle Deposits - Insights into their Formation and Growth Mechanisms

Modern diesel passenger car technology continues to develop rapidly in response to demanding emissions, performance, refinement, cost and fuel efficiency requirements. This has included the implementation of high pressure common rail fuel systems employing high precision injectors with complex injection strategies, higher hydraulic efficiency injector nozzles and in some cases <100µm nozzle hole diameters. With the trend towards lower diameter diesel injector nozzle holes and reduced cleaning through cavitation with higher hydraulic efficiency nozzles, it is increasingly important to focus on understanding the mechanism of diesel injector nozzle deposit formation and growth. In this study such deposits were analysed by cross-sectioning the diesel injector along the length of the nozzle hole enabling in-depth analysis of deposit morphology and composition change from the inlet to the outlet, using state-of-the-art electron microscopy techniques.
Technical Paper

A Closed Cycle, High-Altitude Rotary Engine for Unmanned Ozone Sampler

This paper documents the design and validation of a closed cycle propulsion system suitable for use on the Perseus A high altitude research aircraft. The atmospheric science community is expected to be the primary user of this aircraft with initial missions devoted to the study of ozone depletion and global warming. To date large amounts of funding are not available to the atmospheric science community, so to be useful, the aircraft must satisfy stringent cost and performance criteria. Among these, the aircraft has to be capable of carrying 50 kg of payload to altitudes of at least 25km, have a initial cost in the $1-2M range, be capable of launch from remote sites, and be available no later than 1994. These operational criteria set narrow boundaries for propulsion system cost, complexity, availability, reliability, and logistical support requirements.
Technical Paper

A Closer Look at the Willans-Line

The Willans line represents the relationship between fuel energy input and engine output. Extrapolation to a zero line of fuel input provides a useful approximation of the mechanical losses. Linearity of these curves is assumed in the range from low load downward to a hypothetical zero value of the indicated work. A critical analysis revealed that these lines must have a continued curvature and also that the location of the zero point of indicated power does not coincide with zero fuel input. The paper suggests corrections and defines a directional field which may improve the accuracy of the loss analysis.
Technical Paper

A Combined Physical / Neural Approach for Real-Time Models of Losses in Combustion Engines

Reliable estimation of pumping and friction losses in modern combustion engines allows better control strategies aiming at optimal fuel consumption and emissions. Sophisticated simulation tools enable detailed simulation of losses based as well on physical and thermodynamic laws as well as on design data. Models embedded in these tools however are not real-time capable and cannot be implemented into the programs of the electronic control units (ECU's). In this paper an approach is presented that estimates the pumping and friction losses of a combustion engine with variable valve train (VVT). Particularly the pumping losses strongly depend on the control of variable valve train by ECU. The model is based on a combination of a globally physical structure embedding data driven sub models based on test bed measurements. Losses are separated concerning different component groups (bearings, pistons, etc.).
Technical Paper

A Combustion Heat Release Correlation for CAI Combustion Simulation in 4-Stroke Gasoline Engines

One-dimensional engine simulation programmes are often used in the engine design and optimization studies. One of the key requirements of such a simulation programme is its ability to predict the heat release process during combustion. Such simulation software has built in it the heat release models for spark ignited premixed flame and compression ignited diesel combustion. The recent emergence of Controlled Auto Ignition (CAI) combustion, also known as Homogeneous Charge Compression Ignition (HCCI), has generated the need for a third type of heat release models for this new combustion process. In this paper, a heat release correlation for CAI combustion has been derived from extensive in-cylinder pressure data obtained from a Ricardo E6 single cylinder research engine and a multi-cylinder Port Fuel Injection (PFI) gasoline engine running with CAI combustion. The experimental data covered a wide range of air/fuel ratios, speed and percentage of residual gas.
Technical Paper

A Combustion Model for Multi-Component Fuels Based on Reactivity Concept and Single-Surrogate Chemistry Representation

High fidelity engine simulation requires realistic fuel models. Although typical automotive fuels consist of more than few hundreds of hydrocarbon species, researches show that the physical and chemical properties of the real fuels could be represented by appropriate surrogate fuel models. It is desirable to represent the fuel using the same set of physical and chemical surrogate components. However, when the reaction mechanisms for a certain physical surrogate component is not available, the chemistry of the unmatched physical component is described using that of a similar chemical surrogate component at the expense of accuracy. In order to reduce the prediction error while maintaining the computational efficiency, a method of on-the-fly reactivity adjustment (ReAd) of chemical reaction mechanism along with fuel re-distribution based on reactivity is presented and tested in this study.
Technical Paper

A Comparative Analysis of Ethanol Versus Gasoline as a Fuel in Production Four-Stroke Cycle Automotive Engines

This paper presents the findings of a study that compared the fuel efficiency, power, emissions, engine wear and material compatability characteristics of automotive four-stroke cycle engines fueled by E95 (95 % ethyl alcohol and 5% lead free regular gasoline) and 87 pump octane number lead-free gasoline. A group of six senior Automotive Engineering Technology students, conducted the research over a one-year period. Two Mankato State University faculty served as directors for the project. The laboratory facilities at Mankato State University were used for vehicle modification and testing. Two identically equipped 1994 Geo Metros with 1.0 liter, three cylinder, throttle body fuel injected engines were used for this study. After a 6440 km (4000 mile) break-in period, to assure the cars performance characteristics were equal, one of the vehicles was converted to run on E95.
Technical Paper

A Comparative Analysis on the Spray Penetration of Ethanol, Gasoline and Iso-Octane Fuel in a Spark-Ignition Direct-Injection Engine

This study aims to clarify the spray development of ethanol, gasoline and iso-octane fuel, delivered by a multi-hole injector and spark-ignition direct-injection (SIDI) fuelling system. The focus is on how fuel properties impact temporal and spatial evolution of sprays at realistic ambient conditions. Two optical facilities were used: (1) a constant-flow spray chamber simulating cold-start conditions and (2) a single-cylinder SIDI engine running at normal, warmed-up operating conditions. In these optical facilities, high-speed Mie-scattering imaging is performed to measure penetrations of spray plumes at various injection pressures of 4, 7, 11 and 15 MPa. The results show that the effect of fuel type on the tip penetration length of the sprays depends on the injection conditions and the level of fuel jet atomisation and droplet breakup.
Technical Paper

A Comparative Study of the Integrity of Joints Between Multilayer Fuel Line Constructions and Different Connector ‘Barb’ Designs - Part 2

Last year, McKechnie Vehicle Components established (Paper 2000-01-1098) that there were two factors influencing joint integrity between a multilayer fuel tube and the barb design of a plastic quick connector: The relationship between barb O.D. and tube I.D. The type of lining material of the tube and the overall hoop stress the tube applies to the joint after assembly. It was recommended that future work should address the following points if a full understanding of the fuel tube material to barb type is to be achieved: Assess the sealability of different materials onto a common barb type Assess a range of different barb designs to depict the optimum This year the authors have attempted to address the above points. Two conductive liquid fuel tubes of different commercial sizes (American and European) were manufactured in commercial multilayer structures. These had different material inner layers (PA12 and PBT).
Technical Paper

A Comparative Study on Different Dual-Fuel Combustion Modes Fuelled with Gasoline and Diesel

Comparisons have been made between dual-fuel (80% port-injection gasoline and 20% direct-injection diesel by mass) Highly Premixed Charge Combustion (HPCC) and blended-fuel (80% gasoline and 20% diesel) Low Temperature Combustion (LTC) modes on a 1-L single-cylinder test engine. In the HPCC mode, both early-injection (E-HPCC) and late-injection (L-HPCC) of diesel have been used. The comparisons have been conducted with a fixed fuel injection rate of 50 mg/cycle at 1500 rpm, and with the combustion phasing fixed (by adjusting the injection timing) so that the 50% heat release point (CA50) is at 8° ATDC. The rapid heat release process of LTC leads to the highest maximum pressure rise rate (MPRR). A two-peak heat release process is observed in L-HPCC, resulting in a lower MPRR. The heat release rate and MPRR values for the E-HPCC are comparable to the L-HPCC values. The EHPCC mode provides the lowest NOX emission. The soot emissions for all three modes are low.
Technical Paper

A Comparative Study on the Thermodynamic Analysis and Performance Characteristics of a Dedicated EGR Gasoline Engine Under Various D-lambda

The concept of D-EGR (Dedicated EGR) used high EGR rate and fuel reformation to improve thermal efficiency, entire exhaust gas which supplied from a single cylinder is recirculated to the intake system and then entered into all cylinders to improve combustion. In this study, the D-EGR system is performed on a 1.5 L port fuel injection 4-cylinder gasoline engine, in comparison to the basic engine, the reduction of fuel consumption is about 20~30 g/kWh in most of the D-EGR engine operating range, a maximum 104.1 g/kWh BSFC reduction is found at 14.0bar@1800rpm, the lowest fuel consumption is decreased from 253.7 to 224.3 g/kWh by D-EGR, and the corresponding maximum brake thermal efficiency is improved from 32.6 to 36.9%. D-lambda (the lambda of dedicated cylinder) is considered as the most significant factor to influence the fuel economy and combustion stability, the suitable range of D-lambda is around 0.69~0.82 to gain better engine performance under the whole operating points.
Technical Paper

A Comparison of Burn Characteristics and Exhaust Emissions from Off-Highway Engines Fueled by E0 and E85

Ethanol fuel has received renewed attention in recent years because of its oxygenate content and its potential to reduce greenhouse gas emissions from spark ignition engines. The economic impact on farm industry has been one of the drivers for its use in engines in the U.S. Although ethanol, in various blends, has been used in automotive engines for almost a decade the fuel has seldom been utilized in off-highway engines where the fuel systems are not well controlled. This investigation was conducted to evaluate exhaust emissions and combustion characteristics of E85 fuel in an off-highway engine used in farm equipment. A single-cylinder, four-stroke, spark ignition engine equipped with a carburetor was used to investigate combustion and exhaust emissions produced by gasoline and blends of gasoline and ethanol fuels. The engine fuel system was modified to handle flow rates required by the engine. A variable size-metering orifice was used to control air-to-fuel ratios.
Technical Paper

A Comparison of Fixed Wing Reusable Booster Concepts

Eight fixed-wing reusable horizontal landing booster point design concepts are presented and compared on the basis of weight, cost, technical difficulty, and availability date. The eight vehicle types considered are all basically two-stage systems with a lifting body reusable second stage, with all vehicles normalized to place 40,000 lbs. payload in orbit. All flight vehicles are fully recoverable and capable of flying back and landing at the launch site. Vehicle types discussed are vertical take-off horizontal landing rockets, sled launched horizontal take-off rockets, runway launched horizontal take-off rockets, air breathing first stages, combined air breathing and rocket first stages, oxidizer collection concepts, supersonic combustion ramjets, and in-flight refueling vehicles. Each of these vehicle types is depicted in the paper and its design and performance characteristics are discussed.
Technical Paper

A Comparison of Four Methods for Determining the Octane Index and K on a Modern Engine with Upstream, Port or Direct Injection

Combustion in modern spark-ignition (SI) engines is increasingly knock-limited with the wide adoption of downsizing and turbocharging technologies. Fuel autoignition conditions are different in these engines compared to the standard Research Octane Number (RON) and Motor Octane Numbers (MON) tests. The Octane Index, OI = RON - K(RON-MON), has been proposed as a means to characterize the actual fuel anti-knock performance in modern engines. The K-factor, by definition equal to 0 and 1 for the RON and MON tests respectively, is intended to characterize the deviation of modern engine operation from these standard octane tests. Accurate knowledge of K is of central importance to the OI model; however, a single method for determining K has not been well accepted in the literature.
Technical Paper

A Comparison of Fuel Distribution and Combustion During Engine Cold Start for Direct and Port Fuel Injection Systems

Experiments have been conducted in a firing single-cylinder spark-ignition engine employing a Ford Zetec cylinder head that has been modified to operate with either standard port-fuel-injection, air-forced port-fuel-injection or direct-injection. The engine utilizes a fused silica cylinder and therefore provides extensive optical access to the combustion chamber. Tests were conducted using a constant speed simulated cold start procedure, which is composed of an initial start-up transient and a quasi-steady-state idle period. In this procedure, the engine is briefly motored at 889 rpm and then combustion commences shortly after the start of fuel injection. Measurements which were performed include in-cylinder pressure as well as intake valve, exhaust valve, piston, cylinder, head, and intake air temperature throughout each cycle of the test period. The engine-out total hydrocarbon emissions were also measured.