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Journal : JURNAL TEKNOLOGI TECHNOSCIENTIA

ANALISIS FAKTOR GESEKAN PADA PIPA LURUS DENGAN VARIASI DEBIT ALIRAN Subagyo, Rachmat
JURNAL TEKNOLOGI TECHNOSCIENTIA Technoscientia Vol 3 No 2 Februari 2011
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v3i2.483

Abstract

Distribution of laminar or turbulent flow is strongly influenced by the Reynolds number, Viscosity, pressure gradient and surface roughness. High coefficient of friction affect directly to a substantial reduction in pressure and eventually to the energy needed to push the fluid. Because of the role of the coefficient of friction is very important in the flow, so study has been conducted on the straight pipe, and friction factor with the variation of flow rate, by measuring pressure at two particular points to determine the loss. From the experimental results it can be concluded that the friction factor will be smaller in value with increasing Reynolds number and with the increase of Re, the friction factor value will be more stable. In the first experiment the highest friction factor occurs at Re = 4,30 x 104 with a value of f = 2,195 x 10-2 for the second experiment at Re = 1,41 x 104 with a value of f = 2,462 x 10-2 and the third experiment at Re = 2,39 x 104 with a value of f = 2,461 x 10-2. And for the lowest value occurred at Re = 1,91 x 105 with a value of f = 1,513 x 10-2, Re = 1,86 x 105 with a value of f = 1,521 x 10-2 and Re = 1,75 x 105 with a value of f = 1,544 x 10-2. At Re numbers began to 1,50 x 104 - 2 x 104 value of the friction factor tends to be stable (unchanged). The difference calculation from the experimental to the theoretical friction factor is 1,37% and to the moody diagram is = 1,14%.
KAJI EKSPERIMENTAL KARAKTERISTIK ALIRAN EKSTERNAL PADA BENDA TUMPUL SEGIEMPAT DENGAN UJUNG MUKA ELLIPS Subagyo, Rachmat
JURNAL TEKNOLOGI TECHNOSCIENTIA Technoscientia Vol 4 No 2 Februari 2012
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v4i2.519

Abstract

Aerodynamic equilibrium at the vehicle can not be separated from the presence of flow separation and drag force that occurs, and is a great loss that can affect the use of waste fuels. Many ways to minimize the drag force that arises when a body drained of fluid flow, one of which is to control the boundary layer on the surface of the object or to modify the shape of the object. In this research using wind tunnel aerofoil as a tool to tes while the test object is made using teak wood in the form of ellipse as much as 5 pieces. The surface of the test object is made smooth and varnished.The results are: AlphaThe smaller the drag coefficient with the increasing Reynolds number and variety of the major axis (a) on the test object, and conversely the smaller the value of the Reynolds number and variety of the major axis is smaller drag coefficient. With different Reynolds numbers show almost the same pressure distribution of the five test specimens except the specimen 75 mm major axis variation of this happens because the influence of the capillary tube. The greater the radius of curvature or the greater variation the separasion nough major axis can be delayed can be seen in the figure based separasi point (b / a) for the fifth test object that the separation point can be delayed due to the fluid flowing in the test specimen experienced less resistance because of its shape more taper than another test.
ANALISIS KARAKTERISTIK POMPA SENTRIFUGAL DENGAN SISTEM SERI DAN PARALEL Subagyo, Rachmat; -, Muchsin; Aulia, Rezky
JURNAL TEKNOLOGI TECHNOSCIENTIA Technoscientia Vol 5 No 2 Februari 2013
Publisher : Lembaga Penelitian & Pengabdian Kepada Masyarakat (LPPM), IST AKPRIND Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.34151/technoscientia.v5i2.546

Abstract

The pump is a device for providing mechanical energy to the fluid. At the pump, the fluid density is constant and large. The pump is intended for the transport fluid (horizontal and vertical), raising the pressure and increase speed. The main weakness of the centrifugal pump is located on the limitation of the pressure blower (delivery presure) and not able to provoke their own. For that use multi-level which is usually the same wheelbase and driven by the motor. Various circuits can be used to satisfy a certain condition. Namely series and parallel systems, where a parallel system to increase the pump head and the series system To increase the flow rate.To overcome these problems the research conducted on the characteristics of the pump between the pump with series and parallel systems. To find out the advantages of each characteristic. In this activity, carried out research using the dependent variable valve opening, the load and the volume of water comprising: valve openings ¼, ½, ¾ and 1 and for loading performed at a load 0.25 kg, 0.5 kg, 0.75 kg and 1kg and to use as much water 5 litre, while independent variables are used, namely engine speed of 2980 rpm most of the worth of the smallest worth up to 2945 rpm, the pressure at the pump in and out and the time spent to reach the volume of water by 5 litre. From the test results shows that the comparison between series and parallel pumps each have advantages, further increase in the pump head series and parallel pump further improve the discharge, the pump power and highest efficiency in parallel with 112.79 worth of watts and 65% and the power series highest pump valued at 113.00 watts and the highest efficiency of 53%.