Combustion and pollutant characteristics of IC engines fueled with hydrogen and diesel/hydrogen mixtures using 3D computations with detailed chemical kinetics

In order to develop design guidelines for optimum operations of internal combustion engines fueled with alternative fuels, a comprehensive understanding combustion behavior and the pollutant formation inside the cylinder are needed. The first part of this thesis aimed to numerically study the engine performance and in-cylinder pollutant formation in a spark ignition engine fueled with hydrogen. Advanced simulations were performed using multi- dimensional software AVL FIRE coupled with CHEMKIN. The detailed chemical reactions with 29 steps of hydrogen oxidation with additional nitrogen oxidation reactions were also employed. Formation rates of nitrogen oxides (NOx) within the engine were accurately predicted using the extended Zeldovich mechanism with parameters adjusted for a carbon-free fuel. The computational results were first validated against experimental results with different equivalence ratios and then employed to examine a spark-ignition engine fueled with hydrogen under different operating conditions. Strategies that could have significant effects on the engine performance and emissions, such as exhaust gas recirculation (EGR) and ignition timing were also investigated. Furthermore, the maximization of engine power and minimization of NOx emissions were considered as conflicting objectives for preliminary optimization. Finally, a skeletal reaction mechanism was developed to include the reaction kinetics of diesel and hydrogen fuel mixtures to investigate in-cylinder combustion processes of such a dual fuel compression-ignition engine. The model was then employed to examine the effects of exhaust gas recirculation (EGR) and N2 dilution on NOx emissions --Abstract, page iii

Robotics Control Using Active Disturbance Rejection Control

Conventional robotics control has been set in stone since the sixties. The world has been waiting too long for a new age of control to change the world of Robotics. Active Disturbance Rejection Control (ADRC) is a newly reformed Control methodology. It has been used, in very limited applications, as a replacement for PID control. In this thesis, I will cover the different aspects of the kinematics and dynamics of a robotic manipulator. I will also examine the feasibility of using ADRC to control a robotic manipulator. To explain ADRC, a simple example that demonstrates the concepts and theory of Active Disturbance Rejection Control will be discussed. Using this example, the establishment of relevance to the mathematical module of a rotary prismatic robotic manipulator will be accomplished. A control system for the module using Matlab software and mathematical computations will be implemente

Robotics Control Using Active Disturbance Rejection Control

Conventional robotics control has been set in stone since the sixties. The world has been waiting too long for a new age of control to change the world of Robotics. Active Disturbance Rejection Control (ADRC) is a newly reformed Control methodology. It has been used, in very limited applications, as a replacement for PID control. In this thesis, I will cover the different aspects of the kinematics and dynamics of a robotic manipulator. I will also examine the feasibility of using ADRC to control a robotic manipulator. To explain ADRC, a simple example that demonstrates the concepts and theory of Active Disturbance Rejection Control will be discussed. Using this example, the establishment of relevance to the mathematical module of a rotary prismatic robotic manipulator will be accomplished. A control system for the module using Matlab software and mathematical computations will be implemente

Robotics Control Using Active Disturbance Rejection Control

Conventional robotics control has been set in stone since the sixties. The world has been waiting too long for a new age of control to change the world of Robotics. Active Disturbance Rejection Control (ADRC) is a newly reformed Control methodology. It has been used, in very limited applications, as a replacement for PID control. In this thesis, I will cover the different aspects of the kinematics and dynamics of a robotic manipulator. I will also examine the feasibility of using ADRC to control a robotic manipulator. To explain ADRC, a simple example that demonstrates the concepts and theory of Active Disturbance Rejection Control will be discussed. Using this example, the establishment of relevance to the mathematical module of a rotary prismatic robotic manipulator will be accomplished. A control system for the module using Matlab software and mathematical computations will be implemente

Superfluidity of Dense 4^4He in Vycor

We calculate properties of a model of $^4$He in Vycor using the Path Integral Monte Carlo method. We find that $^4$He forms a distinct layered structure with a highly localized first layer, a disordered second layer with some atoms delocalized and able to give rise to the observed superfluid response, and higher layers nearly perfect crystals. The addition of a single $^3$He atom was enough to bring down the total superfluidity by blocking the exchange in the second layer. Our results are consistent with the persistent liquid layer model to explain the observations. Such a model may be relevant to the experiments on bulk solid $^4$He, if there is a fine network of grain boundaries in those systems.Comment: 4 pages, 4 figure