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Full-Text Articles in Mechanical Engineering

A Road Grade Based Weighting System For Calculating On-Road Distance-Specific Oxides Of Nitrogen Emissions Of Light-Duty Diesel Vehicles, Jason D. Bolyard Jan 2021

A Road Grade Based Weighting System For Calculating On-Road Distance-Specific Oxides Of Nitrogen Emissions Of Light-Duty Diesel Vehicles, Jason D. Bolyard

Graduate Theses, Dissertations, and Problem Reports

Light-duty diesel vehicles have received significant public and governmental scrutiny recently for violating emissions regulations. Similar to the heavy-duty diesel manufacturers during the late 1990’s, some light-duty manufacturers were implementing different control strategies between laboratory certification tests and customer on-road operation. These devices allowed the vehicle to pass certification tests but then use alternative operation on the road during normal use. The alternative operation would allow for better fuel economy but higher oxides of nitrogen (NOx) emissions. Light-duty vehicles are currently certified in the US using chassis dynamometer testing. The effects of all on-road driving conditions are not mimicked in …


Development Of A 2d Scr Catalyst On A Diesel Particulate Filter Model For Design And Control Applications To A Ultra Low Nox Aftertreatment System, Venkata Chundru Jan 2019

Development Of A 2d Scr Catalyst On A Diesel Particulate Filter Model For Design And Control Applications To A Ultra Low Nox Aftertreatment System, Venkata Chundru

Dissertations, Master's Theses and Master's Reports

This research focuses on modeling and control of PM and NOx in diesel engine exhaust using an SCR catalyst on a Diesel Particulate Filter (SCR-F). A 2D SCR-F model was developed that is capable of predicting internal states: 2D temperature, PM and NH3storage distributions and filtration efficiency, pressure drop, PM mass retained in the PM cake and substrate wall and outlet NO, NO2and NH3concentrations. The SCR-F model was used to simulate a DOC + SCR-F + DOC + SCR ultra-low NOx system that can achieve > 99.5% NOx conversion efficiency.

The model was calibrated …


Study Of American Wood Pellet Stove Emissions, Sergio Gamarra Jan 2019

Study Of American Wood Pellet Stove Emissions, Sergio Gamarra

All Graduate Theses, Dissertations, and Other Capstone Projects

Problem: The EPA (Environmental Protection Agency) had not specified emissions performance standards for pellet burning stoves. Instead they were lumped in with cordwood burning stoves. IRETI’s decision to pursue this baseline study was guided by Minnesota’s concurrent “2025 Energy Action Plan” and the EPA’s pellet stove testing method development. Wood pellet fuel, a renewable resource, and the technology developed to utilize it for residential heating should be further studied to examine how together they both stand up to newly developed EPA emissions testing methods. This will establish a benchmark for testing American technology, thus guiding IRETI’s efforts of introducing foreign …


Reduction Of Nox Emissions In A Single Cylinder Diesel Engine Using Sncr With In-Cylinder Injection Of Aqueous Urea, Anthony Timpanaro Jan 2019

Reduction Of Nox Emissions In A Single Cylinder Diesel Engine Using Sncr With In-Cylinder Injection Of Aqueous Urea, Anthony Timpanaro

UNF Graduate Theses and Dissertations

The subject of this study is the effect of in-cylinder selective non-catalytic reduction (SNCR) of NOx emissions in diesel exhaust gas by means of direct injection of aqueous urea ((NH2)2CO) into the combustion chamber. A single cylinder diesel test engine was modified to accept an electronically controlled secondary common rail injection system to deliver the aqueous urea directly into the cylinder during engine operation.

Direct in-cylinder injection was chosen in order to ensure precise delivery of the reducing agent without the risk of any premature reactions taking place. Unlike direct in-cylinder injection of neat water, …


Experimental Design, Testing, And Evaluation Of Methods To Improve The Efficiency And Reduce Emissions From A Small Two-Stroke Natural Gas Engine, Christopher Joseph Ulishney Jan 2018

Experimental Design, Testing, And Evaluation Of Methods To Improve The Efficiency And Reduce Emissions From A Small Two-Stroke Natural Gas Engine, Christopher Joseph Ulishney

Graduate Theses, Dissertations, and Problem Reports

Decentralized power generation is a research area of interest due to possible improvements in electrical generation efficiency and grid resilience. Two-stroke engines are simple, inexpensive, power dense systems that could serve as the prime-movers for combined heat and power (CHP) systems. In addition, such systems could be fueled on natural gas (NG) that is readily available to serve as a reliable fuel source in most households. However, most two-stroke engines are inefficient and produce excessive emissions. This research focused on methods to simultaneously improve engine efficiency and decrease emissions from a 34 cc air-cooled, two-stroke engine retrofitted to operate on …


Reduced Exhaust Emissions Through Blending N-Butanol With Ultra Low Sulfur Diesel And Synthetic Paraffinic Kerosene In Reactivity Controlled Compression Ignition Combustion, Remi Gaubert Jan 2018

Reduced Exhaust Emissions Through Blending N-Butanol With Ultra Low Sulfur Diesel And Synthetic Paraffinic Kerosene In Reactivity Controlled Compression Ignition Combustion, Remi Gaubert

Electronic Theses and Dissertations

Increasing restrictions on the emitted exhaust emissions in diesel engines are becoming a more challenging task than in previous years. An electronic common rail fuel injection system and a port fuel injection (PFI) system were developed for an experimental engine to research dual fuel combustion. The experimental research was conducted at 1500 rpm and 4, 5, and 6 bar indicated mean effective pressure (IMEP). n-Butanol was port fuel injected at a 60% by mass fraction coupled with direct injection (DI) of three fuels, including ultra-low sulfur diesel (ULSD RCCI), a 50-50 wt-% blend of ULSD and butanol (ULSD-Bu RCCI), and …


Incorporation Of Higher Carbon Number Alcohols In Gasoline Blends For Application In Spark-Ignition Engines, Kristina Lawyer Jan 2017

Incorporation Of Higher Carbon Number Alcohols In Gasoline Blends For Application In Spark-Ignition Engines, Kristina Lawyer

Dissertations, Master's Theses and Master's Reports

The 2007 U.S. Renewable Fuel Standard (RFS2) requires an increase in the use of advanced biofuels up to 36 billion gallons by 2022. Higher carbon number alcohols, in addition to cellulosic ethanol and synthetic biofuels, could be used to meet this demand while adhering to the RFS2 corn-based ethanol limitation. Alcohols of carbon numbers 2 through 8 are chosen based on their chemical and engine-related properties.

Blend comparison metrics are developed from automotive industry trends, consumer expectations, U.S. fuel legislation, and engine requirements. The metrics are then used to create scenarios by which to compare higher alcohol fuel blends to …


Economical Retrofit System To Reduce Cooking Emissions In Third World Dwellings, Jonathan Vanzummeren, Tyler Sturgeon, Ben Dalessandro Jan 2016

Economical Retrofit System To Reduce Cooking Emissions In Third World Dwellings, Jonathan Vanzummeren, Tyler Sturgeon, Ben Dalessandro

Williams Honors College, Honors Research Projects

Abstract:

The purpose of this document is to propose and demonstrate the feasibility and effectiveness of substituting an open flame biomass cooking process with a closed system with the capabilities of sustaining an adequate fire. Clay ovens or “chulhas” are the traditional piece of cooking equipment used in poorer areas of the world. They are often built inside cramped one-room housing units with little or no ventilation. The emissions released from burning fuel sources such as wood, coal, or animal waste bring with them detrimental and often fatal health problems and results in approximately 1.3 million deaths per year.

The …


Computational Fluid Dynamics Modeling Of The Effects Of Water Injection In A Diesel Engine, Rabun Z. Wallace Jan 2015

Computational Fluid Dynamics Modeling Of The Effects Of Water Injection In A Diesel Engine, Rabun Z. Wallace

Electronic Theses and Dissertations

Water injection has been used in internal combustion engines for many years. It has been used to cool combustion temperatures, reduce emissions, and in some instances clean carbon buildup from the cylinder. Research has shown that the water to fuel mass ratio is most effective between 20-30%, so the upper and lower limit were used for simulations in Converge CFD. To validate the CFD model, a case without water injection was compared to experimental data from Sandia National Laboratory. The predicted in-cylinder pressure and heat release rate showed good agreement with the experimental data. Cases were run with the injection …


Analysis Of Biomass/Coal Co-Gasification For Integrated Gasification Combined Cycle (Igcc) Systems With Carbon Capture, Henry A. Long Iii Dec 2011

Analysis Of Biomass/Coal Co-Gasification For Integrated Gasification Combined Cycle (Igcc) Systems With Carbon Capture, Henry A. Long Iii

University of New Orleans Theses and Dissertations

In recent years, Integrated Gasification Combined Cycle Technology (IGCC) has become more common in clean coal power operations with carbon capture and sequestration (CCS). Great efforts have been spent on investigating ways to improve the efficiency, reduce costs, and further reduce greenhouse gas emissions. This study focuses on investigating two approaches to achieve these goals. First, replace the subcritical Rankine steam cycle with a supercritical steam cycle. Second, add different amounts of biomass as feedstock to reduce emissions. Finally, implement several types of CCS, including sweet- and sour-shift pre-combustion and post-combustion.

Using the software, Thermoflow®, this study shows that utilizing …