Refine Your Search

Topic

Author

Search Results

Technical Paper

DI Boost: Application of a High Performance Gasoline Direct Injection Concept

2007-04-16
2007-01-1410
The development of engines with high specific output and low specific fuel consumption is now more than ever becoming the main focus for powertrain product development. A combination of two primary factors is driving this demand: increased fuel cost and stricter government regulations. As worldwide fuel prices continue to increase, consumers are shifting their purchasing toward more fuel-efficient vehicles. Also fueling the demand is new federal corporate average fuel economy (CAFÉ) regulations that are in place for the timeframe from 2008 to 2011. One concept to provide both high specific output and low specific fuel consumption is the combination of turbocharging and gasoline direct fuel injection. This is an attractive concept for the North American market where sport utility vehicles, light trucks and sports cars of all sizes are in demand from consumers.
Technical Paper

Cummins K-Series Engines

1974-02-01
740036
New heavy-duty diesel engines of 6-, 8-, 12-, and 16-cyl rated 75 hp/cyl turbocharged and 100 hp/cyl turbocharged and aftercooled are being developed. Design and development objectives include maximizing engine durability/reliability and use of common parts in all engine models. Fuel consumption, smoke, exhaust gas emissions, and engine noise equal or better than the best current engines within engine configurations readily adaptable to current automotive and construction equipment are also prime considerations. Initial models of the engine series meet the design and development objectives.
Technical Paper

Design Aspects of Low-Noise Diesel Engines

1973-02-01
730246
Methods of reducing the noise level of a diesel engine include the suppression of the major modes of block vibration and treatment of the external surfaces. Design methods enable the frequencies and noise levels of these modes to be calculated for a conventionally designed engine. The important modes of vibration, the noise signature and the effect of block modifications of a standard production V-8 engine were found by experiments. These provided the basis for the design of an experimental low-noise engine. Design features include a suffer block, removal of the bottom part of the crankcase skirt, the addition of a single bearing beam, and the use of isolated panels and damped surfaces. The noise reduction obtained was 9 dBA. Most of this is due to the use of isolated and damped nonload carrying surfaces.
Technical Paper

Tribological Investigations for an Insulated Diesel Engine

1983-02-01
830319
A Minimum Cooled Engine (MCE) has been successfully run for 250 hours at rated condition of 298 kW and 1900 rpm. This engine was all metallic without any coolant in the block and lower part of the heads. Ring/liner/lubricant system and thermal loading on the liner at top ring reversal (TRR) as well as on the piston are presented and discussed. Ring/liner wear is given as well as oil consumption and blow-by data during the endurance run. Another engine build with a different top ring coating and several lubricants suggested that a 1500 hours endurance run of MCE is achievable. Rig test data for screening ring materials and synthetic lubricants necessary for a successful operation of a so-called Adiabatic Engine with the ring/ceramic liner (SiN) interface temperature up to 650°C are presented and discussed.
Technical Paper

An Evaluation of the Lucas Combustion Noise Meter on Cummins ‘B’ Series Engines

1987-08-01
870952
Lucas Industries Noise Centre has introduced a combustion noise meter which is designed to predict the contribution of the combustion process to overall diesel engine noise. The performance of the meter is evaluated using Cummins B series engines in naturally-aspirated and turbocharged form. Combustion noise levels predicted by the meter are compared to levels determined using traditional techniques. The effects of several engine operating parameters on combustion noise are investigated under both steady state and accelerating conditions. The meter reliably predicts changes in combustion noise levels, and is a useful tool for performance development engineers. Combustion noise is shown to be related to the maximum rate of pressure rise at the onset of combustion, but combustion noise is not reliably related to maximum cylinder pressures.
Technical Paper

Test Cell Simulation of the Driveby Noise Test

1987-08-01
870967
Diesel engine manufacturers have traditionally done most engine noise development work under steady: state operating conditions. However, truck driveby noise tests are acceleration tests, and engines exhibit different noise behavior under accelerating conditions. Acceleration noise can be affected by engine performance parameters which may have no influence on steady state noise levels. In this study, a test cell simulation of the truck driveby procedure has been developed and evaluated. Test cell simulation and truck driveby results are compared for a naturally-aspirated and a turbocharged engine. This simulation procedure has been shown to predict reliably results measured in vehicles. As a result, the simulation can be used to evaluate engine modifications during the development process without requiring a vehicle installation.
Technical Paper

Combustion Chamber Insulation Effect on the Performance of a Low Heat Rejection Cummins V-903 Engine

1986-03-01
860317
Cummins Engine Company is developing a low heat rejection 450 kW engine under contract for the US Army Tank & Automotive Command. This paper discusses progress made toward achieving the program goals of 6.6 kcal/kW-min brake specific heat rejection and 200 g/kW-hr brake specific fuel consumption. Methodology for measuring heat rejection on a low heat rejection engine is presented. Design improvements of the base engine are discussed along with their effect on improving fuel consumption. Performance test data is assessed in terms of the first law energy balance and cooling load distribution. The heat rejection data provides insights on the performance of insulating components and two cooling system designs. Diesel cycle simulations are compared to the test data and are used to predict the effect of ceramic insulation on engine heat rejection.
Technical Paper

A Transient Spray Mixing Model for Diesel Combustion

1976-02-01
760128
A transient spray mixing model forming the basis of heterogeneous combustion in direct injection diesel engines is described. Experimental results of transient fuel sprays in a high pressure, high temperature chamber form the basis of spray growth equations. Use of similarity of concentration profile across the spray in conjunction with spray geometry and mass conservation yields a complete description of spatial and temporal fuel-air distribution. Fuel preparation and air entrainment rates are calculated from the history of fuel-air distribution. Progressive evolution of combustion zones is determined by the fuel-air mixing process. Energy conservation and chemical kinetics calculations in each zone yield cylinder pressure and local nitric oxide concentration. The role of fuel-air mixing in diesel combustion is discussed. The model results are compared with experimental data.
Technical Paper

The Influence of Bowl Offset on Air motion in a Direct Injection Diesel Engine

1988-10-01
881611
The influence of bowl offset on motored mean flow and turbulence in a direct injection diesel engine has been examined with the aid of a multi-dimensional flow code. Results are presented for three piston geometries. The bowl geometry of each piston was the same, while the offset between the bowl and the cylinder axis was varied from 0.0 to 9.6% of the bore. The swirl ratio at intake valve closing was also varied from 2.60 to 4.27. It was found that the angular momentum of the air at TDC was decreased by less than 8% when the bowl was offset. Nevertheless, the mean (squish and swirl) flows were strongly affected by the offset. In addition, the distribution of turbulent kinetic energy (predicted by the k-e model) was modified. Moderate increases (10% or less) in mass averaged turbulence intensity at TDC with offset were observed. However, the TDC turbulent diffusivity was changed less than 3% due to a slight decrease in turbulent length scale with increasing offset.
Technical Paper

The Effect of Raising Specific Output of a Highly Rated DI Diesel Truck Engine on its Performance and Emissions

1989-02-01
890263
A study was undertaken to establish what happens to engine emissions, and to turbocharger and injection pressure requirements, as the specific output is raised. For any given engine package, increasing specific output increases injection pressures while reducing air/fuel ratios. Thus, if the highly rated engine must satisfy the same design constraints, then raising the engine operating torque by only 10% resulted in more than 30% increase in total particulates! However, the same emission levels may be maintained if increases in specific output are accompanied by changes to engine design so as to maintain the air-fuel mixing parameters, specifically air/fuel ratio and injection pressures, throughout the entire engine operating conditions.
Technical Paper

Systems Approach to Meeting EPA 2010 Heavy-Duty Emission Standards Using a NOx Adsorber Catalyst and Diesel Particle Filter on a 15L Engine

2004-03-08
2004-01-0587
This paper outlines the development and integration of an advanced emission control system with a modern heavy-duty diesel engine for use in a series of catalyst aging tests. The project that is discussed is one of several being conducted under the Department of Energy's Advanced Petroleum-Based Fuels - Diesel Emission Control (APBF-DEC) activity. This government/industry collaboration is examining how systems of advanced fuels, engines, and emission control systems can deliver significantly lower emissions while maintaining or improving vehicle fuel economy. This project is using a Cummins ISX EGR engine (15 L) with a secondary fuel injection system to enable NOx adsorber catalyst regeneration. Development of the strategies for NOx regeneration and sulfur removal as well as integration of the emission control hardware is discussed. Performance of oven aged systems tested over transient and steady-state cycles is summarized.
Technical Paper

Testing Procedures for Introduction of Silicon Carbide and Carbon Water Pump Seal Faces into Heavy Duty Diesel Service

1993-03-01
930585
Testing procedures to evaluate new coolant pump seal face materials and new coolant pump seal designs were evaluated. Rig testing of materials and seals followed by engine dynamometer testing enabled changes in the seal materials or design to be validated prior to field testing and limited production. These procedures were used to test and implement a coolant pump seal face material change to silicon carbide versus carbon. The change resulted in higher reliability for the coolant pump seal and reduced warranty cost for the engine.
Technical Paper

Combustion Chamber Component Analysis for Advanced Heavy Duty Diesel Engines

1989-09-01
891900
Detailed thermal analysis was conducted on several advanced cylinder head, liner, and piston concepts, for low heat rejection diesel engines. The analysis was used to define an optimized engine configuration. Results pointed to the strategic use of oil cooling and insulation in the cylinder head, an oil cooled cylinder liner, and an insulated piston, with separate insulation behind the compression rings. Such a configuration reduced in-cylinder heat rejection by 30 percent, while durability would be expected to be maintained or improved from today's production levels.
Technical Paper

Validation of Methods for Rapid Design and Performance Prediction of Water Pumps

2001-05-14
2001-01-1715
Tools for the design and evaluation of engine water pumps have been developed. These tools range from textbook calculations to 3-dimensional computational fluid dynamics methods. The choice of the tools or the combination of tools used is usually dependent upon production timelines, rather than technical merit. Therefore, the strengths and weaknesses of each of the tools must be understood, and each tool must be validated for its specific purpose, then used appropriately to aid in the design or development of a water pump suitable for production. This study was carried out to evaluate three approaches: a proprietary Ricardo approach based on 1-dimensional analysis and correlations, a 3-dimensional computational fluid dynamics approach, and a conventional prototype manufacture and test iteration approach. The analytical results were correlated to experimentally obtained pressure rise, mass flow rate, and impeller speed data.
Technical Paper

Heavy Duty Truck Cooling System Design Using Co-Simulation

2001-05-14
2001-01-1707
In order to meet the legislated emissions levels, future diesel engines will likely utilize cooled exhaust gas re-circulation (EGR) to reduce emissions. The addition of the EGR cooler to the conventional vehicle coolant system creates several challenges. Firstly, the engine cooling system flow and heat rejection requirements both increase as it is likely that some EGR will be required at the rated power condition. This adversely affects packaging and fuel economy. The system design is further complicated by the fact that the peak duty of the EGR cooler occurs at part load, low speed conditions, whereas the cooling system is traditionally designed to handle maximum heat duties at the rated power condition of the engine. To address the system design challenges, Ricardo have undertaken an analytical study to evaluate the performance of different cooling system strategies which incorporate EGR coolers.
Technical Paper

A Preliminary Model for the Formation of Nitric Oxide in Direct Injection Diesel Engines and Its Application in Parametric Studies

1973-02-01
730083
A semiempirical, mathematical model describing the formation of nitric oxide in direct-injection diesel engines is derived. The model is used in conjunction with injection and thermodynamic cycle simulation programs. This approach enables prediction of nitric oxide emissions from design dimensions and operating parameters only, without the use of experimental data. Predicted results are compared with experiments for typical naturally aspirated and turbocharged engines. The accuracy of prediction is very good except under light-load naturally aspirated conditions. The model is used in an extensive parametric study, together with experimental verification. The agreement between prediction and experiments is excellent, except under conditions of excessive smoke or of high swirl.
Technical Paper

Diesel Engine Noise Reduction Hardware for Vehicle Noise Control

1973-02-01
730681
A range of noise reduction hardware is described for three production engine models, as well as the rationale for selecting noise reduction methods. Noise reductions up to 6 dB(A) were achieved with this hardware in the test cell. In many cases the modifications are more effective in vehicles. The success of the hardware in reducing overall vehicle noise is illustrated.
Technical Paper

Diesel Engine Component Design Using the Finite Element Method and Interactive Graphics

1974-02-01
740337
An inexpensive, flexible and convenient finite element analysis system can be implemented with limited capital and resources. A system of this nature can be a functional tool of the designer and stress analyst for the analysis of many types of mechanical components. The finite element models generated by this system can approach a high degree of complexity with a small time investment compared to the time required to do this job without the aid of the system described.
Technical Paper

A Study of the Effects of Spark Plug Electrode Design on 4-Cycle Spark-Ignition Engine Performance

2000-03-06
2000-01-1210
Engine tests were conducted on a production 2.5-liter V-6 engine to investigate the effects of spark plug tip designs on a 4-cycle SI engine of current technology. The data suggest that cyclic variation can increase when the ground electrode faces the primary intake port. Lean-operation limits were extended by the use of J-gap spark plugs as compared to surface-gap and ring-gap spark plugs at the conditions tested. The surface-gap type spark plugs lose some energy as the arc traverses the surface of the insulator. Voltage requirements decrease for reversed polarity at the part load conditions tested but increase at wide open throttle.
Technical Paper

Evaluation of Microalloyed Steel for Articulated Piston Applications in Heavy Duty Diesel Engines

2000-03-06
2000-01-1232
AISI-4140H steel has been used as articulated piston crown material in heavy-duty engines. With the driving force for reducing manufacturing cost, microalloyed steel (MAS) was identified as a low-cost material to replace 4140H steel. In order to determine the feasibility of using MAS to replace 4140H steel, a test program was initiated to fully evaluate the material properties of MAS and to compare them to those of the baseline 4140H steel. The physical and mechanical properties of both materials from room temperature to 550°C were evaluated. The effect of long term thermal exposure on the material properties was also studied. Some engine tests were also conducted to evaluate the performance of the articulated pistons made with both materials. The inherently lower strength of MAS as compared to 4140H steel, requires a total re-design of the piston for the utilization of MAS as a low-cost replacement material for 4140H steel.
X