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Numerous works have been carried out in the design and analysis of Heat Sink, however hardly any work have been reported with studies on dimples and protrusions being added to the heat sink geometries. This paper aims to find the worthiness for addition of dimples and protrusions to the common plate fin heat sink geometries for heat transfer enhancement. Analysis was carried out in forced convention environment for 9 different velocities computationally for 12 heat sink geometries at constant heat flux boundary condition applied to base of heat sink. Decrease in base temperature and thermal resistance of heat sink was considered as the performance factors. Further these computational results were validated experimentally. The results obtained from computational analysis were in good agreement with experimental results. The research outcome show that addition of dimples has proved its worthiness at slightly higher velocity regime with thermal performance being increased for a dimpled heat sink as compared to non-dimpled heat sink. Therefore, currently developed dimpled heat sinks can be a potential model that can be used in forced convection environment for better thermal performance and economy. [ABSTRACT FROM AUTHOR]

This paper presents the results of an experimental study to evaluate the possibility of using SLM additive technology to produce structures with specific surface morphological features. Qualitative and quantitative tests were conducted on samples fabricated by 3D printing from titanium (Ti6Al4V)-powder-based material and analysed in direct relation to the possibility of their use in medicine for the construction of femoral stem and models with a specific degree of porosity predicted by process-control in the self-decision-making 3D printing machine. This paper presents the results of the study, limitations of the method, recommendations that should be used in the design of finished products, and design proposals to support the fabrication process of 3D printers. Furthermore, the study contains an evaluation of how the printing direction affects the formation of certain structures on the printed surface. The research can be used in the development of 3D printing standardization, particularly in the consideration of process control and surface control. [ABSTRACT FROM AUTHOR]

This paper described unique hysteresis phenomena that appear in the hydrodynamic lubrication properties of dimpled thrust bearings. A seal-type thrust bearing specimen was textured with dimples. The load-carrying capacity and frictional torque were measured with a constant film thickness and compared to those of a dimple-free specimen. For examining the size of cavitation bubbles that occurred in various conditions, the lubricating area was observed during experiments. The used dimpled specimen produced the load-carrying capacity, and it exhibited an interesting hysteresis phenomenon, the difference in the values in the increasing and decreasing processes of rotational speed. The visualization test results revealed that the size of cavitation bubbles occurring within the dimples strongly affected this phenomenon. In addition, the dimpled specimen was able to reduce the frictional torque compared to the dimple-free specimen. However, the frictional torque did not show the hysteresis loop similar to that shown in the load-carrying capacity. [ABSTRACT FROM AUTHOR]

In this paper, the influence of occurrence of surface texture features on the values of surface topography parameters calculated after the application of various data processing techniques was presented. Different types of surface topographies were considered, as follows: cylinder liners, some with additionally burnished dimples, turned, ground, milled, laser-textured, composite, ceramic, or isotropic in general. The effects of feature size on the areal form removal, noise suppressions, or end-effect reducing in surface texture measurements were studied. The variations of the ISO 25178 standard surface topography parameters were taken into consideration in detail. It was assumed that some of the feature sizes, distributions, and densities have a substantial impact on the values of surface topography parameters calculated after applications of regular (commonly used) algorithms and procedures, defined as basic operations, provided for raw surface texture data obtained directly from the measurement process. In the end, some of the practical applications for receiving the relevant values of surface topography parameters were proposed. [ABSTRACT FROM AUTHOR]