The in-cylinder pressure is an important signal that gives information about the combustion process. To further improve engine performance, this information can be used as a feedback signal in a control system. Usually a pressure sensor is mounted in the cylinder to extract this information. A drawback with pressure sensors is that they are expensive and have issues with aging. This master’s thesis investigates the possibility to create a virtual sensor to estimate in-cylinder pressure based on crank angle degree sensor (CAD-sensor) data and physical models of the heavy-duty engine. Instead of using the standard mounted CAD-sensor an optical high-precision sensor measures the elapsed time between equidistant angles. Based on this signal the instantaneous angular acceleration was estimated. Together with the inertia of the crankshaft, connecting rods and pistons, an estimation of the engine torque was calculated. To be able to extract in-cylinder pressure from the estimated torque, knowledge about how the in-cylinder pressure signal propagates in the drivetrain to accelerate the flywheel needs to be known. Two engine models based on the torque balance on the crankshaft are presented. The fundamental difference between them is how the crankshaft is modeled, rigid body or spring-mass-damper system. The latter captures torsional effects of the crankshaft. Comparisons between the estimated torque from sensor data and the two engine models are presented. It is found that torsional effects of the crankshaft is present at normal engine speeds and has a significant influence on the flywheel torque. A separation of the gas torque contribution from one cylinder is done with CAD-sensor data together with the rigid body engine model. The in-cylinder pressure is then estimated by using the inverse crank-slider function and a Kalman filter estimator. The estimated pressure captures part of the compression and most of the expansion at engine speeds below 1200 RPM. Due to the crank-slider geometry the pressure signal disappears at TDC. The torsional effects perturb the estimated pressure during the gas exchange cycle. Further development must be made if this method is to be used on heavy-duty applications in the future.

Call number: LD2668 .T4 1935 H31

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Doctor of Philosophy / The ancient region of Elam (southwestern Iran) has produced a significant assemblage of cylinder seals across a considerable chronological span. Unlike the glyptic material from the related and neighbouring region Mesopotamia, the Elamite cylinder seals have not previously been studied in detailed reference to one another, nor has there been an established paradigm of stylistic development articulated. This study addresses this lacuna by compiling all the published cylinder seals from Elam (as defined here, thus incorporating the historical provinces of Khuzistan, Luristan and Fars), from their earliest appearance (c.3500 BC), throughout the era of their typological dominance (over stamp seals, thus this study departs c.1000 BC). This compilation is presented in the Elamite Cylinder Seal Catalogue (Volume II), and is annotated and described through the annunciation of eighteen chronologically defined developmental styles (with another two non-chronological type classifications and four miscellaneous groups). Through the further analysis of this data, including the newly formulated and articulated styles, several facets and problems of Elamite glyptic material have been addressed (and thus the reliance upon assumed similarity in type and function with the Mesopotamian glyptic material is abandoned). These problems particularly pertain to the function of cylinder seals in Elam and the type and form of the Elamite-Mesopotamian glyptic interaction. In regards to function, a standard administrative function can be discerned, though of varying types and forms across the region and the period of study. Other, non-standard, symbolic glyptic functions can also be demonstrated in the Corpus, including the apparent proliferation of a form known as the ‘votive’ seal, perhaps a specifically Elamite form. The analysis of the style type (whether ‘Elamite’, ‘Mesopotamian Related’ or ‘Shared Elamite-Mesopotamian’), in association with their relative geographical and chronological distribution, has also enabled the discussion of the nature of Elamite-Mesopotamian glyptic interaction, and thereby the constitution of Elamite civilisation (especially in regards to Mesopotamian cultural impact and influence, and thus the testing of several previously presented paradigms [Amiet 1979a; 1979b; Miroschedji 2003]).

<p>The cylinder liners’ surface is really important in an engine because it corresponds with piston rings to a tribologic system indispensable to know for reasons of wear, of oil consumption and engine’s life time. For these reasons, it is important to measure and characterize these surfaces.</p><p>The first part of the project is the observation of the impact of the number of strokes of the plateau honing on the surface of the cylinder liners. It is interesting to observe the impact of the variation of the number of strokes of the plateau honing on the peaks, plateaus and valleys of the surface.</p><p>The second part of the project is the simulation of the oil flow on the surface to observe the links between the roughness parameters and the oil flow and the shear stress.</p><p>The results are interesting, we will observe that the number of strokes of honing as a good impact on the quality of the surface.</p><p>In the second part of the project, the results show a correlation between the machining parameters and the roughness and functional parameters.</p><p>It could be interesting to mix the two parts of the project to see the correlation among machining, roughness and functional parameters for the samples made in the first of the project.</p>

The cylinder liners’ surface is really important in an engine because it corresponds with piston rings to a tribologic system indispensable to know for reasons of wear, of oil consumption and engine’s life time. For these reasons, it is important to measure and characterize these surfaces. The first part of the project is the observation of the impact of the number of strokes of the plateau honing on the surface of the cylinder liners. It is interesting to observe the impact of the variation of the number of strokes of the plateau honing on the peaks, plateaus and valleys of the surface. The second part of the project is the simulation of the oil flow on the surface to observe the links between the roughness parameters and the oil flow and the shear stress. The results are interesting, we will observe that the number of strokes of honing as a good impact on the quality of the surface. In the second part of the project, the results show a correlation between the machining parameters and the roughness and functional parameters. It could be interesting to mix the two parts of the project to see the correlation among machining, roughness and functional parameters for the samples made in the first of the project.

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