A5040481477- Advanced Combustion Engine Technologies
- Combustion and flame dynamics
- Nuclear Physics and Applications
- Granular flow and fluidized beds
- Vehicle emissions and performance
- Thermochemical Biomass Conversion Processes
- Nonlinear Dynamics and Pattern Formation
- Chaos control and synchronization
- Heat transfer and supercritical fluids
- Nuclear reactor physics and engineering
- Biodiesel Production and Applications
- Complex Systems and Time Series Analysis
- Combustion and Detonation Processes
- Catalytic Processes in Materials Science
- Mineral Processing and Grinding
- Fluid Dynamics and Mixing
- Coal Properties and Utilization
- Thermography and Photoacoustic Techniques
- Time Series Analysis and Forecasting
- Advanced Thermodynamic Systems and Engines
- Particle Dynamics in Fluid Flows
- Real-time simulation and control systems
- Radiation Detection and Scintillator Technologies
- stochastic dynamics and bifurcation
- Advanced Power Generation Technologies
Oak Ridge National Laboratory
2015-2024
University of Southampton
2024
Natural Resources Conservation Service
2023
National Transportation Research Center
2002-2022
Government of the United States of America
2022
GE Global Research (United States)
2017
University of Science and Technology
2017
Google (United States)
2014
Environmental Energy & Engineering
2006
University of Tennessee at Knoxville
1995-2000
We propose a low-dimensional, physically motivated, nonlinear map as model for cyclic combustion variation in spark-ignited internal engines. A key feature is the interaction between stochastic, small-scale fluctuations engine parameters and deterministic coupling successive cycles. Residual cylinder gas from each cycle alters in-cylinder fuel-air ratio thus efficiency succeeding The model's simplicity allows rapid simulation of thousands cycles, permitting statistical studies...
We describe a symbolic approach for measuring temporal "irreversibility" in time-series measurements. Temporal irreversibility is important because it excludes Gaussian linear dynamics and static transformations of such from the set possible generating processes. A method attractive computationally efficient, robust to noise, simplifies statistical analysis confidence limits. propose specific algorithm, called "false flipped symbols," establishing presence without need surrogate data....
We propose a simple model that explains important characteristics of cyclic combustion variations in spark-ignited engines. A key feature is the interaction between stochastic, small-scale fluctuations engine parameters and nonlinear deterministic coupling successive cycles. Prior-cycle effects are produced by residual cylinder gas which alters mean in-cylinder equivalence ratio subsequent efficiency. The model`s simplicity allows rapid simulation thousands cycles, permitting in-depth...
We present experimental evidence that a complex system of particles suspended by upward-moving gas can exhibit low-dimensional bulk behavior. Specifically, we describe large-scale collective particle motion referred to as slugging in an industrial device known fluidized bed. As flow increases from zero, the evolves fixed point periodic oscillations intermittently punctuated ``stutters,'' which become more frequent further. At highest tested, behavior becomes extremely (``turbulent'').
We present techniques of symbolic time-series analysis which are useful for analyzing temporal patterns in dynamic measurements engine combustion variables. focus primarily on that characterize predictability and the occurrence repeating patterns. These methods can be applied to standard, cycle-resolved measurements, such as IMEP heat release. The especially cases with high levels measurement and/or noise. illustrate their application experimental data from a production V8 laboratory...
Abstract We describe simulation studies of the dynamics spouted beds used for CVD coating nuclear fuel particles. Our principal modeling tool is Multiphase Flow with Interphase eXchanges (MFIX) code that was originally developed by National Energy Technology Laboratory (NETL) fossil energy process applications. In addition to standard MFIX features allow coupling transient hydrodynamics, heat and mass transfer, chemical kinetics, we employ special post‐processing tools track particle mixing...
Maritime shipping is an essential and growing component of international trade, with over 90% all the world's goods being transported on large ocean-going vessels. The sector also among last to reduce criteria pollutants responsible for up 3% global CO2 emissions. For first time, maritime facing regulatory action multiple fronts: reductions in fuel sulfur content, emissions, NOx as well expected upcoming limits black carbon Decarbonizing requires development new sources that do not compete...
The Oak Ridge National Laboratory is planning to build the Second Target Station (STS) at Spallation Neutron Source (SNS). STS will host a suite of novel instruments that complement First Station's beamline capabilities by offering an increased flux for cold neutrons and broader wavelength bandwidth. A neutron imaging beamline, named Complex, Unique, Powerful Imaging Instrument Dynamics (CUPI2D), among first eight be commissioned as part construction project. CUPI2D designed broad range...
We describe a method for detecting and quantifying time irreversibility in experimental engine data. apply this to heat-release measurements from four sparkignited engines under leaning fueling conditions. demonstrate that the observed behavior is inconsistent with linear Gaussian random process more appropriately described as noisy nonlinear dynamical process.
We report experimental observations of the dynamic behavior single, magnetically tagged 3–4 mm particles varying in density from 0.55 g/cm3 to 1.2 as they migrate freely a bubbling air-fluidized bed 177–250 μm glass beads 2.5 over range air flows. The densities tracer (made by imbedding small magnets wooden particles) were chosen span typical for many biomass materials and exhibited both segregated well-mixed behavior. Using high-speed measurements externally mounted magnetic probes, we able...
<div class="section abstract"><div class="htmlview paragraph">Interest in operational cost reduction is driving engine manufacturers to consider low-cost fuel substitution heavy-duty diesel engines. These dual-fuel (DF) engines could be operated either diesel-only mode or with premixed natural gas (NG) ignited by a pilot flame of compression-ignited direct-injected fuel. Under certain conditions, operation can result increased cycle-to-cycle variability (CCV) during combustion. CFD greatly...
Prior studies examining the nonlinear material properties of 6000 series aluminum alloys have predominantly concentrated on analyzing stress–strain characteristics these materials under monotonic tensile loading. Limited research has been conducted their behavior cyclic loading conditions. To address gaps, a and variable increasing amplitude tests was coupons made from 6082-T6, 6063-T6, 6060-T5 alloys. The experimental results revealed that as strain increased showed isotropic hardening....
We describe a CHEMKIN-based multi-zone model that simulates the expected combustion variations in single-cylinder engine fueled with iso-octane as transitions from spark-ignited (SI) to homogenous charge compression ignition (HCCI) combustion. The includes 63-species reaction mechanism and mass energy balances for cylinder exhaust flow. For this study we assumed SI-to-HCCI transition is implemented by means of increasing internal gas recirculation (EGR) at constant speed. This scenario...