Evrimata: Journal of Mechanical Engineering

The Effect of Different Octane Number on Power and Specific Fuel Consumption in Gasoline Compression Ignition Engine

2024-06-27T15:50:06+07:00

Internal combustion motors are a type of engine used as the main source of power for transportation equipment. This engine functions to convert heat energy into kinetic or motion energy. Compression ignition (CI) utilizes the increase in temperature and pressure during compression to ignite the fuel. The octane number or research octane number (RON) indicates the maximum pressure that can be received before gasoline burns itself. A lower octane number increases the likelihood of detonation of the fuel. Gasoline with a higher octane number is basically designed to prevent premature ignition or auto ignition of the gasoline in the engine. This research focuses on the power and specific fuel consumption of gasoline compression ignition engine at each variation in fuel octane number and engine speed. The fuel used is a mixture of 94% gasoline and 6% diesel fuel. The highest average power results at an engine speed of 1900rpm from 90, 92 and 95 octane fuel respectively are 0.475 kW, 0.728 kW and 0.764 kW. The average results of specific fuel consumption at 1900 engine revolutions were obtained for fuel with octane numbers of 90, 92, and 95 respectively at 0.92 L/kWh, 0.91 L/kWh, and 0.65 L/kWh.

The Effect of Root Face Height and Width of Hot-Gas Welding Plate Heater on Tensile Strength of HDPE Sheet

2023-12-14T12:52:06+07:00

Hot-Gas Welding is a welding process that is widely used in plastic materials. In previous studies, there was a phenomenon that occurred, namely the early connection of the parent material before the welding process which affected the tensile strength of HDPE sheets. The purpose of this study was to determine the effect of variations in root face height and width of the anvil heating plate on tensile strength, and also to determine the interaction of the two variables. The welding process of Hot-Gas Welding, by varying two independent variables namely root face height 0 mm, 0.8 mm, 1.6 mm, 2.4 mm and the width of the anvil heating plate 10 mm, 15 mm, and 20 mm. The controlled variables include HDPE material 5 mm thick, HDPE filler 4 mm thick, hot gas temperature 250 ℃, single v bevel shape, anvil plate temperature 150 ℃ and v grove angle 60º. The results of this study indicate that the root face height and anvil plate width affect the tensile strength of hot-gas welding HDPE sheets. The maximum value of tensile strength is 27.09 Mpa or 85.32% of the tensile strength of the parent material. The maximum tensile strength value is obtained from the interaction of the root face height of 2.4 mm and the width of the heating plate of 15 mm. Distortion and linear misalignment weld defects at the highest tensile strength results were identified the least.

Analysis of the Fin Incline Angle on Aerodynamic Stability of 60 mm Caliber Komando Asap Mortgarena Using Computational Fluid Dynamics Simulation Method

2025-05-25T09:49:45+07:00

This study aims to analyze and simulate the aerodynamic performance of the design of a training weapon grenade using the Computational Fluid Dynamics (CFD) method. CFD simulation allows the analysis of airflow around the grenade to identify the distribution of pressure, drag, and aerodynamic coefficients that play an important role in the efficiency of the grenade flight. The grenade design was tested under various conditions of speed and fin angle to understand their effects on stability and flight efficiency. The results of the simulation show that the variation of the mortar grenade with the fin position parallel to the launch angle has a fluid flow velocity of 84.1 m / s, the mortar grenade with the fin position tilted 2.5 has a fluid flow velocity of 82.7 m / s, and the mortar grenade with the fin position tilted 5 has a fluid flow velocity of 85.8 m / s from the data obtained, the inclination of the fin angle significantly affects the aerodynamic performance of the mortar grenade. This study provides insight that shifting the fin angle on the grenade can increase stability and minimize air resistance during flight.

Geometry Optimization of PET Regrind Plastic Dust Separator Machine

2025-05-25T09:47:55+07:00

This study aims to analyze the effect of various operational factors on the weight of dust collected by a dust collector machine. Using a multilevel factorial design, this study evaluates the interaction between frequency (Hz), hose length (m), and tube height (m). Analysis of variance shows that all three factors have a significant effect on the dust weight response (P-Value <0.05). The regression model with an R² of 99.15% shows a very high prediction accuracy. Parameter optimization was carried out to maximize the weight of dust collected, resulting in optimal conditions at a frequency of 50 Hz, a hose length of 2 m, and a tube height of 0.3 m with a dust weight of 72.75 g.