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In aviation, electric propulsion has long been applied, one of which is the electric ducted fan (EDF). In Indonesia, initially, EDF was mostly used for the propulsion of aeromodelling aircraft for hobby purposes. LAPAN initiated the use of EDF as a drone propulsion which flown since 2013. In addition, EDF is also used in the Indonesian Rocket and Rocket Payload Competition (KOMURINDO). KOMURINDO is an annual competition for the design of rocket payloads and Electric Ducted Fan (EDF) rockets at the university level which has been held by LAPAN since 2009. In the EDF rocket competition, EDF is a secondary part of the competition because it is not required to design and build so the participants prefer products ready to use all of which come from abroad. This limits the participants in designing the EDF rocket because, in the design, the EDF specifications must be following the initial design requirements specified. Therefore, this research needs to be carried out as a first step in understanding the design process for the development of EDF. The fan is the main part of the rotating EDF or also called the rotor. Fan plays a vital role in generating thrust through accelerating airflow, so it is necessary to design to produce a fan that suits your needs. The design method used in this research is a combination of the thrust equation for the rotor and the blade element theory. The CFD method is used to analyze the performance of the designed fan which is compared with the experimental test results with the EDF test bed. The results of the design obtained that the EDF fan geometry which produces a thrust based on CFD analysis is much smaller than an initial estimate using the analytical method, it is necessary to carry out an optimization process in the process of determining the fan geometry with a better method so that the resulting thrust is following the initial estimate. The results of the EDF test show that the thrust produced by the EDF is smaller than the results of the CFD analysis, this can be due to the less optimal distance between the fan tip and the duct wall on the EDF being tested due to manufacturing results, causing the appearance of a tip vortex which reduces fan performance. In addition, the flow resistance of the duct surface is not smooth due to the manufacturing process. The CFD method can be the first step to determine the performance of the fan or EDF before proceeding to the prototype testing process because the CFD results are close to the test results. [ABSTRACT FROM AUTHOR]

This study aims to determine the performance of 4 stroke motorcycle 100cc by variation of fuel and additional Cyclonic Air Injection (CAI). This research will show the power and torque that are produced by motorcycles using the dyno test. Dyno test is a laboratory device that can show motorcycle performance by determining engine rotation (RPM), power change, and torque change in variation of speed. CAI is an additional component applied to the vehicle, which causes the airflow initially linear to rotate (swirl) to mix fuel with air more maximally in the combustion engine to increase the combustion efficiency. CAI has 3 blades with 40o with the angle of inclination blade. CAI is placed in the air filter of the motorcycle before the air enters the carburetor. Testing of motorcycle both standard and additional CAI by dyno test with variations of fuel, gasoline RON 88, gasoline RON 92, and gasoline RON 98. According to the data analysis, a motorcycle with gasoline RON 98 can produce the maximum power and torque. Furthermore, additional CAI can also increase power, but the torque is better on a motorcycle with the standard condition. [ABSTRACT FROM AUTHOR]

The steps of rocket development require very details preparation before a flight test is carried out. The development of 200 mm caliber rockets with canards is intended to accomplish the trajectory correction mission so that the rocket flies according to the trajectory predictions that has been determined in its design. A comprehensive simulation is conducted using the Software in the Loop Simulation (SILS) method followed by Hardware in the Loop Simulation (HILS), then utilize one of the optimal types of control, Model Predictive Control (MPC) so that canard control on trajectory correction can be achieved. The simulation was carried out in 2 steps, first step based on the original thrust profile of the 200 mm caliber rocket motor design, and the second step optimized with 2 times of the thrust profile. This is intended to get a longer control time because in this simulation the control range is only limited to speed Mach 1. With 144 s (93.5% total flight time), the MPC can freely and successfully control the trajectory correction, even being able to maneuver to get a shorter or longer flight distance than the original trajectory. Also maneuver to turn right or left, according to the control roll. And it is possible to become a guided missile if adds an outer loop program for navigation. [ABSTRACT FROM AUTHOR]

This research aims to design and manufacture turbo cyclone and intake manifold spacer (IMS) to increase the performance of 4 strokes of motorcycle. Turbo cyclone and intake manifold spacer (IMS) are additional components applied to the vehicle, which causes the airflow initially linear to rotate (swirl) to mix fuel with air more maximally in the combustion engine to increase the combustion efficiency. Turbo cyclone was designed in two different blades (3 and 4 blades) with a 40o with the angle of inclination blade. Intake manifold spacer designed with 24 grooves with a 40o angle. In this study, a turbo cyclone was applied in the air filter before air entered the carburetor. On the other hand, IMS was placed on the manifold to make mixed fuel flow enter the combustion chamber. This research proves that a combination of both turbo cyclone and IMS increased the performance combustion engine of a 4-stroke motorcycle. [ABSTRACT FROM AUTHOR]

Sintered bodies of rice husk ash (RHA) silica/alumina had been made under the pressureless sintering method. This study aimed to improve the properties of the sintered bodies by adding alumina powder as a reinforcing material. First of all, RHA silica powder was ground using a centrifugal hammer mill (CHM) and then, together with the alumina added, sieved at 400 mesh. The composite RHA silica/alumina was subsequently mixed with various ratios of 100:0 wt% to 75:25 wt%, using a rotary drum mixer (RDM) for 1 h. Each ratio was added with 10 wt% Polyvinyl alcohol (PVA) as a binder and mixed in the RDM for 1 h. The green body with a diameter of 8 mm and a thickness of 5 mm is made by the uniaxial pressing method using a mold made of stainless steel. The sintering process was carried out by preheating at 700°C with a holding time of 1 h to remove PVA. The temperature was increased to 1200°C with a holding time of 2 h, and the heating rate was 5°C/min during the sintering process. The characterization of the sintered bodies of the composite was done by observing the microstructure and testing the linear shrinkage, density, and compressive strength. The results showed that the highest mechanical properties, especially compressive strength, were obtained at the composite ratio of 80:20 wt%. This finding was supported by the data on relative density, which was also maximum at that ratio. SEM image shows that the density of the sintered body increased along with the addition of alumina as a reinforcing material. [ABSTRACT FROM AUTHOR]

Bamboo is a material that can grow quickly, cheap and widely available. Its material properties are lightweight but harder and stronger than wood or glass fibre composites. The purpose of this study was to determine the effect of the direction arrangement of petung bamboo blades on the interface of the laminated bamboo fibre matrix. The benefits of this research can contribute to knowledge and innovation to the development of science in the field of ship material technology in the world of education, especially in the shipping field. This research was conducted with a compressive test, tensile test, and shear test on the interface of petung bamboo laminate blade matrix with tangential or radial test direction (x, y, and z axis) using ASTM D143 standard. After testing, it can be concluded that the shear strength and compressive strength are better with perpendicular arrangement, while for tensile strength it is better paired with woven arrangement. The average results obtained for the tensile test was 41.29 kg / cm2 (4,049 MPa), the shear test was 39.98 kg / cm2 (3.92 MPa), and the compressive test was 311.24 kg / cm2 (30 For the average compressive strength of these results can be classified into Class III on BKI Wooden Ship For the best tensile test direction on the Y axis, the best shear test direction on the Z axis, and the best compressive test direction on the X axis. The greater the glue interface in each cm2, the greater the bond strength, because the level of homogeneity increases and the strength of petung bamboo is stronger than the PVAc glue used. [ABSTRACT FROM AUTHOR]

In this work, the effect of the Ni underlayer with different thicknesses on the mechanical properties of Cu surface was studied. A laminated structure of Ni/Cu layer was prepared using electroplating on carbon steel substrates. The nickel layer was firstly plated on the steel using a current voltage of 2.3 V and varied plating times using 30, 60, 90, 120 and 150 minutes. The copper layer was subsequently electroplated on the nickel surface using a fixed current voltage of 1.9 V and plating time of 30 minutes. The result showed that XRD pattern observed on the surface of Ni/Cu coating indicates the formation of Cu single phase instead of Ni/Cu alloy. Application of plating time variations on the Ni underlayer using 30, 60, 90, 120 and 150 minutes produced an average thickness of Ni underlayer with 19.9, 48.4, 50.1, 62.1 and 64.9 µm, respectively. The thickness of Cu as the outer layer for different thickness of Ni was kept constant at approximately 23.66 µm. The hardness measurement on the Cu underlayed by Ni deposited using different plating times indicated that the hardness of Cu was 91.63, 93.20, 97.93, 102.60 and 106.1 HV, respectively. Whereas, the specific wear rates of Cu were 6.59 × 10-6, 6.11 × 10-6, 5.99 × 10-6, 3.63 × 10-6 and 3.55 × 10-6 mm3/kg.m, respectively. The present study showed that the mechanical properties of Cu layer surface with a fixed layer thickness were influenced by the application Ni underlayer with different thicknesses. An increase of Ni underlayer thickness has increased the hardness and specific wear rate of the Cu layer. [ABSTRACT FROM AUTHOR]

Traffic accidents are terrible scourge that occurs in many countries, for developing countries where transportation problems seem like a tangled yarn. Besides its function as an engine compartment cover, the hood of modern compact SUV can also help to manage the impact energy of pedestrian's head in a vehicle-pedestrian impact. This paper presents a compact SUV's outer hood design that has a potential to improve hood ability and also to absorb the impact energy of a pedestrian's head. The developed methodology for the design of a hood configuration aims to provide a compatible design and stress distribution for the left side impact position at WAD 1000 with three different thicknesses (1.25 mm, 1.30 mm and 1.50 mm) of outer hood panel of local compact SUV, taking into consideration the limited space available for deformation. Finite Element Modeling (FEM) software was used in this research to simulate the ANCAP for child pedestrian head impact testing procedures. The results show that the minimum deformation space and meet the requirement for stress (von Mises) value are required to obtain a sturdy design. Moreover, the hood thickness and materials are the main factors that influence stress and deformation value. Finally, 1.25 thickness aluminum alloy is recommended for vehicle hood component and the pedestrian safety. [ABSTRACT FROM AUTHOR]

Dissimilar welding of aluminum is an innovation used to increase the effectiveness and efficiency in making a product or component. It has been applied on the automotive industry, aerospace, and shipbuilding. Aluminum has low weldability in compared with steel material because of the oxide layer on the surface of aluminum. The welding problems of aluminum can be overcome by using a solid state welding such as friction stir welding (FSW). The objective of this study was to determine the strength of the welding joint and the microstructure of dissimilar welding joint with different series of aluminum. The tensile testing was performed with the weld directions of 0° and 45° to assess the formability, hardness testing, and microstructure of FSW. In this study, welding process was conducted to combine aluminum 1100 series (low strength aluminum) and aluminum 6061-T6 series (high strength aluminum) in the 2 mm thickness of aluminum sheet. The analysis was done by making comparison of the strength between dissimilar and similar aluminum series. The results showed that the dissimilar weld types, both in angle orientation of 0° and of 45° had fracture location on the HAZ area of 1100 aluminum series. The highest results of tensile strength were 78.07 MPa and 75.26 MPa for weld angle orientation of 0° and 45°, respectively. Weld angle orientation had significant effect to the strain where value of the welding direction of 0° was 10.99% and of 45° was 13.8%. Hardness test in the weld zone generated diverse values because the material stirring was not homogenous, whereas the similar welding was more stable in the welding area. Microstructure investigation on the dissimilar aluminum welding found a hook defects in the weld nugget. In the HAZ area, the grain size of 6061-T6 increased while of 1100 material decreased. It might be affected by the temperature and the aluminum characteristic. Meanwhile, in weld nugget, the grain size increased due to the stirring tool joint and heating during the welding process. [ABSTRACT FROM AUTHOR]

The objective of the present work was to investigate the mechanical properties of NiCr-Al coating deposited by plasma sputtering technique. NiCr was firstly deposited on a carbon steel surface using sputtering times of 60, 90, 120, 180 and 240 minutes, whereas Al was subsequently deposited using a time of 30 minutes for all specimens. The results showed that the structure of the surface observed by SEM indicates a good density. The structure formation of NiCr-Al was clarified by XRD. The hardness test of the product surface conducted by a Vickers indentation tester indicates that the average hardness of uncoated steel substrate was 172.512 HV. The hardness of NiCr surface was 191.256 HV. Further layer addition using Al on NiCr indicates that the hardness of NiCr-Al surface sputtered by NiCr for 60, 120, 180 and 240 minutes, followed by Al for 30 minutes, were 279.912, 253.056, 231.264 and 213.888 HV, respectively. The reduced hardness of NiCr-Al with the increased sputtering time was attributed to the higher diffusion of Al into NiCr. [ABSTRACT FROM AUTHOR]

The aim of the research work describe in this paper was to design and optimize a permanent magnet linear generator for renewable energy power plants. It is cover of first stage of designing stator and rotor permanent magnet linear generator. Stator design involves determining dimensions, number of slots, diameter of wire, and the number of winding in each slot. The design of the rotor includes rotor manufacture of PVC pipe material, 10 pieces of permanent magnet type ferrite 271 mikroweber, and resin. The second stage was to assemble the stator and rotor that has been done in the first stage to be a permanent magnet linear generator. The third stage was to install a permanent magnet linear generator with induction motors. Further stage was to test performance of a permanent magnet linear generator by utilizing of induction motor as a prime mover experimentally. In this study, permanent magnet linear generator with a rotor consists of five pairs of permanent magnets. The stator consists of 6 slots of the stator frame, each slot mounted stator coil of 200, 300, 400, 500, and 800 windings, and dimensions of wire used was 0.4 mm. The stator frame was made from acrylic. Results of the experiment that, permanent magnet linear generator when no load was able to generate a DC voltage of 14.5 volts at 300 rpm, and at the output of the linear generator when it is connected to the DC fan as a load only generated of 6.7 volts. It concludes that permanent magnet linear generator output can be used as an input device hybrid system. Data obtained from this experiment in laboratory scale can be developed in a larger scale by varying the type of magnet being used, the number of windings, and the speed used to generate more power. [ABSTRACT FROM AUTHOR]

The aim of the research work describe in this paper was to model and simulate aerodynamic behaviour airfoil NACA 2410 completed with flap and slat using CFD. The work was also to distinguish between NACA 2410 using and without flap and slat in term of lift and drag coefficient quality. Simulation was carried out in various angles of attack. NACA 2410 was modelled by mean of design-Foil software and adjust the size geometry related to chord length within Auto Cad software that which would be converted into SolidWork to add flap and slat also angle of attack. Further simulation was undertaken in Ansys 14.5 by adjusting boundary condition. Parameters produced were coefficient of lift, drag, as well as pressure distribution and its velocity. The results showed that increasing angle of attack increased lift and drag coefficient. The use of flap and slat in the airfoil investigated produced much higher lift and drag coefficient. Maximum lift was achieved when airfoil set in 17° and 55° angle of attack without and with flap and slat, and flap deflexion angle of 30° as well as slat distance in x-direction of 4% from the chord in a slat angle of -2°. [ABSTRACT FROM AUTHOR]