Otopro

INVESTIGASI EFEK SOLIDITAS RUNNER TERHADAP PERFORMA TURBIN CROSSFLOW

Abdul Muis Rifai — Tue, 28 Nov 2023 00:00:00 +0700

The crossflow turbine is a popular type of hydropower generator used to convert water energy into electricity. It offers several advantages, including a simple design, reliable performance, and suitability for low-head water flows. This study investigates the effect of runner solidity on the performance of a crossflow turbine. The designed turbine will operate at a three-meter head with a flow rate of 41.55 litters and a runner speed of 300 rpm. The runner design is straightforward, using blades made from four-inch pipes for easy availability and simple manufacturing and repair processes. Variations in runner solidity are achieved by adjusting the number of blades. The investigation uses runners with 15, 20, 25, 30, and 33 blades, representing solidities of 11.7%, 14.6%, 17.5%, and 19.2%, respectively. The results show that the runner developed from a set of blades produced by four-inch pipes, operating under the designed conditions, achieves maximum performance with an efficiency of 81.42% at a solidity of 17.5%, or 30 blades

PENGARUH JUMLAH DAN ARAH SAYATAN TERHADAP HASIL MILLING ALUMINIUM

Nurlia Sari, Akhmad Faizin, Muhammad Fakhruddin, Agus Dani — Tue, 28 Nov 2023 00:00:00 +0700

The quality of production goods, especially milling on aluminum material, is considered good if it is characterized by good surface quality of the components and efficient (short) machining time. There are various factors that affect this. This study investigated the CNC milling machining parameters, namely depth of cut and step over, which were written as the influence of the number and direction of cuts on the surface quality and machining time of aluminum materials. The purpose was to obtain the appropriate parameters so that the machining process is more efficient and with the appropriate quality. The CNC milling used was CNC Dahlih with a 6mm diameter tool, feed rate of 460 mm/min, and rotational speed of 2800 RPM. The variables were vertical cutting direction (depth of cut 5mm) with variations in step over of 0.5 mm, 1 mm, and 2 mm, and horizontal cutting direction (step over 5mm) with variations in depth of cut of 0.5mm, 1mm, and 2mm. So that the number of cuts can be equalized to 4, 6, and 12 in the vertical and horizontal cutting directions. The results showed that the more cuts, the lower the surface roughness, but it increased the machining time.

PENGARUH VARIASI TRAVEL SPEED TERHADAP KEKUATAN TARIK PADA PENGELASAN DISIMILAR METAL DENGAN MIG ROBOTIC WELDING

Kris Witono, Talifatim Machfuroh, Sarjiyana Sarjiyana, Elka Faizal — Tue, 28 Nov 2023 00:00:00 +0700

Welding using dissimilar metals is a new phenomenon in the industrial world. Some studies have already addressed dissimilar metal welding, but they are limited to variations in welding current strength and voltage. None have yet explored welding travel speed, mainly due to the difficulty in controlling it in manual welding. Because of this background, the researcher conducted a study on welding by varying the travel speed. The aim of this research is to elucidate the influence of travel speed on tensile strength in dissimilar metal welding using MIG robotic welding. The study involved joining dissimilar metals, namely low carbon steel and stainless steel (SS 304), using the MIG Robotic Welding process with travel speed variations of 50 cm/second, 60 cm/second, and 70 cm/second. The welding results were then subjected to tensile testing and macrostructure observation of the fracture surfaces. The research findings indicate that the highest tensile strength was achieved at a travel speed of 50 cm/minute, with a maximum tensile strength of 839.8879 MPa.

ANALISIS SUDUT SERANG TERHADAP KARAKTERISTIK AERODINAMIKA PADA BILAH 4412 RPM RENDAH DENGAN METODE CFD 6DOF

Danang Febriyanto, Hangga Wicaksono, Bayu Pranoto, Mochamad Muzaki — Tue, 28 Nov 2023 00:00:00 +0700

At this time the power plant still uses a lot of coal fuel, so it is necessary to look for alternative energy, one of which is wind energy. Wind turbines are devices that can convert kinetic energy in the wind into mechanical energy which is then converted into electrical energy through a generator. The analysis method in this research uses Computational Fluid Dynamics (CFD), Qblade, and experimental validation testing using a wind tunnel. The simulated airfoil types consist of 3 types, namely, NACA 4412, NACA 4415, and FX-60 100 (126). The simulation results show that, the most optimal airfoil is NACA 4412 with an angle of attack of 25° and a wind speed of 8 m/s can produce a torque of 3.55503 Nm, a pressure of 45 Pa, a tangential velocity of 55.495 m/s, and a rotational speed of 529. 94 rpm, while the smallest simulation results are on the FX-60 100 (126) airfoil with an angle of attack of 15° and the same wind speed of 8m/s can produce a torque of 1.60390 Nm, a pressure of 40 Pa, a tangential velocity of 9.06592 m/s, and a rotational speed of 108.2164 rpm. The results of experimental testing of wind turbines where the wind turbine used uses the geometry of NACA 4412 show that an angle of attack of 25 ° and a wind speed of 8m / s produces a large electrical power and rpm with a value of 7.98 Watt and 482.2 rpm respectively

PERBAIKAN PERFORMA MESIN AUTOMATIC VEHICLE DENGAN FUEL-BOOSTER RACING

Sukendro Sasongko, Titik Arlisa, Hery Irawan — Tue, 28 Nov 2023 00:00:00 +0700

The performance enhancing engine of automatic vehicle experimentally investigated by adding a fuel-booster. The study aims to improve the combustion matic engine Honda by adding the fuel addictive reactant. The existence of fuel-addictive reactants enhances engine combustion. Besides that, the high octane number of fuel could be optimized during chemical reactions. Thus, the study investigates the matic motorcycle engine at steady operation. The experiment methods vary the fuel additive concentration. The fuel addictive varied is Eco racing to percentile. Thus, the engine performed by varying sparks (racing spark and standard spark). The engine of matic motorcycle is investigated. The engine performance is studied at the stand dyno test. The specific fuel consumption is scaled by a litre of Pertalite. The gas emissions were probed by a gas analyser. The investigation is conducted by three time replication. The result shows the fuel-addictive reactant (Eco racing) performs the best contributions during an iridium spark installed at the engine. Thus, the engine power was detected at 7,5 Hp. Torque resulted by 26,68 Nm; specific fuel consumption was at 0,048 gram,/Hp.s. Engine-Rpm of 6000 emits CO 0,27%, HC 147 ppm, CO₂ 12,0 %, dan O₂ 20,84 %. Those gas concentrations are still lower and acceptable due to their concentration being lower than that in the national emissions standard.