105,346 research outputs found
Simulation of Roughness and Surface Texture Evolution at Macroscopic Scale During Cylinder Honing Process
Full text linkThe honing process produces surface liners with specific functional properties. Engine performances and life expectancy are directly impacted by the quality of honed surface. The form quality, the roughness and the surface appearance manufactured by honing determine the friction of the piston in the liner. The process is however mechanically complex and the selection of the process parameters is currently based on empirical methods. The aim of this paper is thus to develop a macroscopic simulation environment which will help end-users during this setting-up stage. The development of this virtual tool is based on a space-time discretization and a macroscopic cutting model taking into account local contacts between the workpiece and the abrasive stones. The space-time discretization allows representing the machine environment including the tool, the workpiece and the machine kinematics. The cutting model allows converting kinematics and abrasive contacts in dynamic data and material removal rate by calculation. The cutting model is initially adjusted based on simple experiments. The stock removal equation is then extrapolated to the whole range of stone cutting conditions. This approximation allows simulating the real process and a whole honing cycle. Results are validated by comparison with industrial context experiments. The simulation of the whole honing cycle allows predicting the form quality, one of the roughness criteria and the surface appearance. Moreover, simulation results are represented by means of maps that allow looking at quality criteria for each point of the surface
Mutual influence of cross hatch angle and superficial roughness of honed surfaces on friction in ring-pack tribo-system
Full text linkThe cylinder bore surface texture, widely produced by the honing technique, is an essential factor for a good engine performance (friction, oil consumption, running-in, wear etc.). This explains the improvement and development of various new honing techniques. These different honing processes generate surfaces with various texture features characteristics (roughness, valleys depth, cross hatch angle, etc.). This paper addresses a comparison of ring-pack friction for cylinder surfaces produced by plateau honing and helical slide honing. It takes in consideration the mutual effect of superficial plateau roughness amplitude and honing angle. A numerical model is developed to predict friction within the cylinder ring-pack system in mixed lubrication regime. The results show the effectiveness of helical slide honed surface texture in comparison to plateau honed bore surface
Running-in wear modeling of honed surface for combustion engine cylinder liners
Full text linkThe texture change during running-in alters the performance and efficiency of a tribo-mechanical system. During mass production of cylinder liners, a final finishing stage known as ‘‘plateau honing’’ is commonly added to reduce the running-in wear process of the liner surface. The majority of researchers think that this operation improves the engine efficiency and decreases oil consumption. It was believed that there are close links between the surface topography of honed cylinders change and their wear resistance during running-in. However, these interactions have not yet been established. Some running-in wear models were developed in the open literature to predict topographical surface changes without considering the running-in conditions. The present paper thus investigates the various aspects of the wear modeling that caused running- in problems in honed surfaces and its implications on ring-pack friction performance. To illustrate this, plateau honing experiments under different conditions were first carried out on an instrumented vertical honing machine. The plateau honing experiments characterize the surface modifications during running-in wear of cast-iron engine bores using advanced characterization method. Based on the experimental evidence, a running-in wear model was developed. Finally, a numerical extension of the developed model was applied to solve the Reynolds equation by taking into account the real surface topographies of the engine bore. This enables us to predict realistic friction performance within the cylinder ring-pack tribosystem
Integrated Analytical Strategies for Drug Discovery
Full text linkIrth, H. [Promotor]Niessen, W.M.A. [Promotor]Honing, M. [Copromotor
The effect of groove texture patterns on piston-ring pack friction
Full text linkA cylinder liner possesses fairly intricate surface requirements due to its complicated functions. It needs to provide adequate surface roughness to resist wear as well as to store and retain lubricants during high temperatures. The liner surface texture is anisotropic, produced by the honing process, with resultant deep visible scratches left on it [1]. The prominence of the honing grooves observed suggests that surface texture significantly affects ring-pack performance, although this effect is not clearly understood. In this paper, a numerical model was developed to investigate the effects of groove characteristics on the lubrication condition and friction at the interface between the piston ring and cylinder liner. This model aims to solve the average Reynolds equation, which depends on the real surface topographies of the cylinder liner, and describes the influence of surface irregularities on the lubricant flow under hydrodynamic lubrication conditions, considering lubricant film rupture and cavitations. Numerical results help to determine the optimum lateral groove characteristics to reduce friction and then noxious emissions
Computational modeling of music cognition: a case study on model selection
Full text linkContains fulltext :
74746.pdf (Publisher’s version ) (Open Access)Published as: Honing, H. (2006). Computational modeling of music cognition: a case study on model selection. Music Perception. 23 (5), 365-37612 p
High-resolution screening of metabolite-like lead libraries
Full text linkIrth, H. [Promotor]Niessen, W.M.A. [Promotor]Honing, M. [Promotor]Kool, J. [Copromotor
Aap slaat maat: Op zoek naar de oorsprong van muzikaliteit bij mens en dier
No full textVolgens Henkjan Honing is iedereen die melodieën uit elkaar kan houden en maatgevoel heeft muzikaal. In essentie is de mens een muzikale diersoort, en waarom zou hij de enige zijn? Is muzikaliteit niet juist een eigenschap van álle dieren, een vermogen met een duidelijke biologische basis, zoals Charles Darwin vermoedde? De laatste jaren worden meer en meer dieren gevonden met muzikale trekjes. Een wetenschappelijke mijlpaal was de geelkuifkaketoe Snowball, het eerste dier waarbij maatgevoel werd vastgesteld. Ook Ronan, een Californische zeeleeuw, bleek na training op de maat van muziek te kunnen bewegen. Honing doet in dit boek op spannende wijze verslag van zijn fascinerende onderzoek naar wat ons mensen tot muzikale dieren maakt
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