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EFFECTS OF CONTINUOUS AND FRACTURED RIBS PLACED AT THE ENDWALL SURFACE UPSTREAM OF THE TURBINE-VANE LEADING-EDGE

Total pressure loss, chaotic and heavy flow downstream of the turbine passage exit area are a few effects of the desired increase in inlet temperature input at the upstream part of the turbine vane passage. Huge amount of energy from the cross-flows near the middle of the vane actual chord are transported downstream by this chaotic flow which often results in aerodynamic loss and differential heat penalties. To compare the different arrangement, comparisons of the two geometries, the impact of adding various rib configurations upstream are studied for heat augmentation efficacies. The leading-edge rib(s) effects at the mid-stream of the vane passage are quantitatively examined in this work using computational fluid dynamics (CFD) technique. With the employment of Reynolds Averaged Navier-Stoke energy equations, the geometries are modelled choosing the appropriate boundary conditions. Polyhedral mesh is used with fifteen prism layer mesh at the endwall and vane surfaces to capture the flow physics close to the endwall area. Although the two configurations employed showed relative reduction in the total pressure loss coefficient, however, the fractured ribs produced superior outcomes of Nusselt number reduction of over 10% along the passage exit region. The data demonstrate a considerable difference in the overall pressure loss between the two configurations.

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THE EFFECT OF ZNO/CUO-WATER- HYBRID NANOFLUID CONCENTRATION RATIO ON HEAT TRANSFER CHARACTERISTICS IN ELECTRONIC EQUIPMENT COOLING SYSTEMS

The use of hybrid nanofluids CuO-ZnO /distilled water as a cooling medium was tested in this study to determine the characteristics of convection heat transfer. The hybrid nanofluids preparation process was carried out first by dispersing the CuO and ZnO nanofluids using an ultrasonic cleaner for 3 hours and then allowed to settle for 24 hours. Furthermore, the CuO and ZnO nanofluids were mixed based on the stipulated ration of CuO:ZnO (25%:75%), (50%:50%) and (75%:25) with a volume fraction of 0.5% and agitated for 1 hour. Testing of the hybrid nanofluids CuO-ZnO/distilled water was carried out using a water block as an electronic cooling device with a flow rate variation of 0.7 – 1.9 l/min. From experimental results, the convection coefficient, as one of performance parameters of cooling device, and its relation to Reynolds numbers was able to be determined. Overall, the results show that the rate of heat transfer with the hybrid nanofluids is higher compared to distilled water. At a particular configuration of flowrate and nanoparticle ratio, the hybrid nanofluid has more than 2.5 times higher coefficient of convection than distilled water. In addition, the experiment revealed that the synthesized nanofluid created a temperature drop of around 40ᵒC across the water block at a heater power of 10 W.

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COMPARATIVE ANALYSIS OF PRESSURE AND FLOW CHARACTERISTICS IN BASIC AND MODIFIED AIR COMPRESSOR PIPELINE USING COMPUTATIONAL FLUID DYNAMICS IN POWER PLANT TANJUNG ENIM 3X10 MW

Air compressor plays a crucial role by converting electrical energy into kinetic energy in the form of compressed air. This study specifically concentrates on assessing the performance of two compressors that operate alternately, with one compressor in standby mode. Unfortunately, compressor unit #1 faced issues with its drying system, rendering it unable to function within the current pipe network. In order to rectify this, proposed modifications to the pipeline network are introduced and scrutinized. To analyze these modifications, Computational Fluid Dynamics (CFD) is employed to evaluate and compare pressure and flow characteristics in both the existing and modified pipe configurations. The CFD analysis utilizes computer engineering software, with SolidWorks serving as the primary modeling and simulation tool. The assumption is made that the Reynolds number corresponds to laminar flow, factoring in pipe diameter and compressor volume rate.The resulting CFD data offers valuable insights into pressure and velocity distributions within the existing and modified pipeline networks. During the pressure simulation, surface pressure and output on both standard and modified pipes exhibit relatively similar pressure values at 7 bar. However, in the air velocity simulation, surfaces of standard and modified pipes maintain a consistent range of 0 – 5 mm/s. Notably, from the pipe output side, air velocity in standard and modified pipes displays distinct speed contours. Standard pipes show the highest speed between 0.25 – 0.38 mm/s, whereas modified pipes exhibit the highest speed within the range of 0.15 – 0.2 mm/s. This study aims to provide a comprehensive evaluation of the proposed modifications, seeking to enhance understanding of the fluid dynamics within air compressor systems. The outcomes of this research have the potential to contribute significantly to optimizing the performance and efficiency of these systems, thereby offering benefits across various industrial applications.

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ANALYSIS OF CUTTING FLUID ON MASS LOSS OF CARBIDE INSERT IN THE MILLING PROCESS

The Machining process is manufacturing in the world industry that is widely used. The coolant in the machining process functions to lower the temperature and lubricate and clean the gram in the cutting process. The application of coolant in the cutting process is to maintain the quality of the workpiece during the cutting process and also serves to improve tool life so that the tool does not wear out easily. This study aims to determine the effect of a chemical-based coolant based on dromus oil and vegetable CPO on tool wear in the face milling process and to determine whether or not the liquid is effective in reducing and slowing down tool wear. In this research, the face milling process used a grey cast iron specimen as the workpiece specimen used and also used a carbide insert chisel cutting tool with the TPKN 22 VC2 type. The research was carried out by varying the engine speed and also the coolant variation, the engine speed variations used were 80, 360 and 720 Rpm. In the process of administering coolant using the method, it is sprayed directly onto the workpiece area which is cut continuously, in the milling process with a response variable that can be in the form of data or tool wear values that have been observed and tested using a microscope test tool, using the weight (mass) method to see the wear value. This research aims to see how effective the use of vegetable- based coolant (CPO) during experiments as a coolant in the machining process aims to ensure that the final value of tool insert wear must be smaller with (CPO) compared to chemical coolant (dromus).

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