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Technical Paper

Time-Resolved, Speciated Emissions from an SI Engine During Starting and Warm-Up

1996-10-01
961955
A sampling system was developed to measure the evolution of the speciated hydrocarbon emissions from a single-cylinder SI engine in a simulated starting and warm-up procedure. A sequence of exhaust samples was drawn and stored for gas chromatograph analysis. The individual sampling aperture was set at 0.13 s which corresponds to ∼ 1 cycle at 900 rpm. The positions of the apertures (in time) were controlled by a computer and were spaced appropriately to capture the warm-up process. The time resolution was of the order of 1 to 2 cycles (at 900 rpm). Results for four different fuels are reported: n-pentane/iso-octane mixture at volume ratio of 20/80 to study the effect of a light fuel component in the mixture; n-decane/iso-octane mixture at 10/90 to study the effect of a heavy fuel component in the mixture; m-xylene and iso-octane at 25/75 to study the effect of an aromatics in the mixture; and a calibration gasoline.
Technical Paper

Chain Representations of Dimensional Control: A Producibility Input for Concurrent Concept Design

1998-06-02
981846
Two critical milestones that must be achieved during concept design are 1) definition of a product architecture that meets performance, producibility, and strategic objectives, and 2) estimation of the integration risk in each candidate concept. This paper addresses these issues by describing the role played by the producibility members of an Integrated Product Team (IPT) during concept design. Our focus is on the execution of the what we call the “chain method”, which illustrates the structure of function delivery in a concept in a simple pictorial way and helps the IPT to understand the advantages or disadvantages of using a modular or an integral product architecture. The producibility members play a central role in capturing and evaluating the chains for different candidate concepts and decompositions.
Technical Paper

Cost Awareness in Design: The Role of Data Commonality

1996-02-01
960008
Enhanced information management techniques made available through emerging Information Technology platforms hold a promise of providing significant improvements in both the effectiveness and efficiency of developing complex products. Determining actual management implementations that deliver on this promise has often proven elusive. Work in conjunction with the Lean Aircraft Initiative at MIT has revealed a straight forward use of Information Technology that portends significant cost reductions. By integrating previously separate types of data involved in the process of product development, engineers and designers can make decisions that will significantly reduce ultimate costs. Since the results presented are not specific to particular technologies or manufacturing processes, the conclusions are broadly applicable.
Technical Paper

Optimal Forming of Aluminum 2008-T4 Conical Cups Using Force Trajectory Control

1993-03-01
930286
In this paper we investigate the optimal forming of conical cups of AL 2008-T4 through the use of real-time process control. We consider a flat, frictional binder the force of which can be determined precisely through closed-loop control. Initially the force is held constant throughout the forming of the cup, and various levels of force are tested experimentally and with numerical simulation. Excellent agreement between experiment and simulation is observed. The effects of binder force on cup shape, thickness distribution, failure mode and cup failure height are investigated, and an “optimal” constant binder force is determined. For this optimal case, the corresponding punch force is recorded as a function of punch displacement and is used in subsequent closed-loop control experiments. In addition to the constant force test, a trial variable binder force test was performed to extend the failure height beyond that obtained using the “optimal” constant force level.
Technical Paper

Time Resolved Measurements of Exhaust Composition and Flow Rate in a Wankel Engine

1975-02-01
750024
Measurements were made of exhaust histories of the following species: unburned hydrocarbons (HC), carbon monoxide, carbon dioxide, oxygen, and nitric oxide (NO). The measurements show that the exhaust flow can be divided into two distinct phases: a leading gas low in HC and high in NO followed by a trailing gas high in HC and low in NO. Calculations of time resolved equivalence ratio throughout the exhaust process show no evidence of a stratified combustion. The exhaust mass flow rate is time resolved by forcing the flow to be locally quasi-steady at an orifice placed in the exhaust pipe. The results with the quasi-steady assumption are shown to be consistent with the measurements. Predictions are made of time resolved mass flow rate which compare favorably to the experimental data base. The composition and flow histories provide sufficient information to calculate the time resolved flow rates of the individual species measured.
Technical Paper

Urban Vehicle Design Competition - History, Progress, Development

1972-02-01
720497
The Urban Vehicle Design Competition was inspired by the success of the Clean Air Car Race and the Great Electric Car Race. The academic community recognized the tremendous educational value of these events, and encouraged development of UVDC from its inception. The project was designed by engineering students to benefit students throughout North America. The rules of the competition include technical paper requirements that make the competition extremely attractive to professors who wish to build a course around this theme. The response of more than 2000 engineering students at 80 universities throughout the United States and Canada has indicated the success of the structure of the competition. The first major objective of the UVDC project has been met. Ninety-three teams throughout the country entered the UVDC design portion of the contest. The second portion of the project is the prototype contest of August 1972.
Technical Paper

Substitution of Steam for Nitrogen as a Working Fluid in Atmosphere Free Spark Ignition Engines - Theory and Test Results for Steam, Oxygen, and Fuel

1962-01-01
620235
This paper summarizes the results of both the preliminary studies and the initial cycle tests of a unique type of IC engine capable of operating in the absence of an atmosphere. This engine has been designed specifically for use in the general space program, and it is intended to satisfy requirements of high power to weight ratio, reliability, compactness, and short development time. The history of the en-engine's development is discussed together with problems encountered in the study. However, primary emphasis is on the recently conducted cycle tests.
Technical Paper

Engine Wear Modeling with Sensitivity to Lubricant Chemistry: A Theoretical Framework

2007-04-16
2007-01-1566
The life of an automotive engine is often limited by the ability of its components to resist wear. Zinc dialkyldithiophosphate (ZDDP) is an engine oil additive that reduces wear in an engine by forming solid antiwear films at points of moving contact. The effects of this additive are fairly well understood, but there is little theory behind the kinetics of antiwear film formation and removal. This lack of dynamic modeling makes it difficult to predict the effects of wear at the design stage for an engine component or a lubricant formulation. The purpose of this discussion is to develop a framework for modeling the formation and evolution of ZDDP antiwear films based on the relevant chemical pathways and physical mechanisms at work.
Technical Paper

The Effects of Sulfated Ash, Phosphorus and Sulfur on Diesel Aftertreatment Systems - A Review

2007-07-23
2007-01-1922
This paper reviews the relevant literature on the effects of sulfated ash, phosphorus, and sulfur on DPF, LNT, and SCR catalysts. Exhaust backpressure increase due to DPF ash accumulation, as well as the rate at which ash is consumed from the sump, were the most studied lubricant-derived DPF effects. Based on several studies, a doubling of backpressure can be estimated to occur within 270,000 to 490,000 km when using a 1.0% sulfated ash oil. Postmortem DPF analysis and exhaust gas measurements revealed that approximately 35% to 65% less ash was lost from the sump than was expected based on bulk oil consumption estimates. Despite significant effects from lubricant sulfur and phosphorus, loss of LNT NOX reduction efficiency is dominated by fuel sulfur effects. Phosphorus has been determined to have a mild poisoning effect on SCR catalysts. The extent of the effect that lubricant phosphorus and sulfur have on DOCs remains unclear, however, it appears to be minor.
Technical Paper

Application of a Lean Cellular Design Decomposition to Automotive Component Manufacturing System Design

1999-05-10
1999-01-1620
A design framework based on the principles of lean manufacturing and axiomatic design was used as a guideline for designing an automotive component manufacturing system. A brief overview of this design decomposition is given to review its structure and usefulness. Examples are examined to demonstrate how this design framework was applied to the design of a gear manufacturing system. These examples demonstrate the impact that low-level design decisions can have on high-level system objectives and the need for a systems-thinking approach in manufacturing system design. Results are presented to show the estimated performance improvements resulting from the new system design.
Technical Paper

Requirements and Potential for Enhanced EVA Information Interfaces

2003-07-07
2003-01-2413
NASA has long recognized the advantages of providing improved information interfaces to EVA astronauts and has pursued this goal through a number of development programs over the past decade. None of these activities or parallel efforts in industry and academia has so far resulted in the development of an operational system to replace or augment the current extravehicular mobility unit (EMU) Display and Controls Module (DCM) display and cuff checklist. Recent advances in display, communications, and information processing technologies offer exciting new opportunities for EVA information interfaces that can better serve the needs of a variety of NASA missions. Hamilton Sundstrand Space Systems International (HSSSI) has been collaborating with Simon Fraser University and others on the NASA Haughton Mars Project and with researchers at the Massachusetts Institute of Technology (MIT), Boeing, and Symbol Technologies in investigating these possibilities.
Technical Paper

High Power Cell for Mild and Strong Hybrid Applications Including Chevrolet Malibu

2017-03-28
2017-01-1200
Electric vehicles have a strong potential to reduce a continued dependence on fossil fuels and help the environment by reducing pollution. Despite the desirable advantage, the introduction of electrified vehicles into the market place continues to be a challenge due to cost, safety, and life of the batteries. General Motors continues to bring vehicles to market with varying level of hybrid functionality. Since the introduction of Li-ion batteries by Sony Corporation in 1991 for the consumer market, significant progress has been made over the past 25 years. Due to market pull for consumer electronic products, power and energy densities have significantly increased, while costs have dropped. As a result, Li-ion batteries have become the technology of choice for automotive applications considering space and mass is very critical for the vehicles.
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