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The development of 3D printing is now widely used for various purposes. This technology has developed rapidly and is quite promising in its use. One of the uses was food printing with a 3d printer technique. 3D printers to print chocolate food will increase food product innovation because food can be printed based on certain customizations. In 3D food printing, the printout results were expected to match its size, shape, and smoothness. In order for the 3D printed food prints to reach the expected shape, it is necessary to set the right parameters. There are several influential parameters, including printing speed, extrusion capacity, and nozzle diameter. Each of these parameters is interrelated and influences each other. In this study, the parameters of extrusion capacity and printing speed have been varied to determine the effect of each parameter on the quality of chocolate printing. Movement speed variations have been set to 100 mm/min, 350 mm/min, and 600 mm/min. The chocolate extrusion capacity is set based on the percentage of the machine's default condition. The test was carried out with a temperature maintained at 33°C-37°C. The results of the study obtained a relationship between movement speed and flow. The faster the speed of movement will require a larger extrusion capacity as well. [ABSTRACT FROM AUTHOR]

Water tunnel (WaTu) visualization techniques have been in high demand to analyze aerodynamic characters in the delta-aircraft model because of clearer and more detailed results. The visualization was used to observe the aerodynamic characteristic of the rolled-up vortex phenomenon on delta-wing. The difference in fluid and flow parameters became an issue of the accuracy of the results. Therefore, testing parameters need to be analyzed so that the results of the WaTu test have been able to represent the real conditions. This research has varied the velocity to investigate the delta-wing aerodynamic characteristics using GAMA water tunnel. The results were compared with computational fluid dynamics (CFD) results based on WaTu and real (subsonic) conditions, as well as several other references. The results showed a similarity in the vortex breakdown location (VBL) at all flow rates in the WaTu and CFD. The CFD results also showed that the coefficient of pressure (Cp) on the wing had the same results in all tests, both based on WaTu and real conditions. Likewise, for a lift and drag coefficient (Cl-Cd), values for all states approached the same amount with a difference of less than 5%. Finally, the uses of the WaTu method has been able to represent the actual conditions in vortex dynamics cases in delta aircraft with the optimum velocity to produce the best visualization around 0.1 m/s. [ABSTRACT FROM AUTHOR]

The improvement of the performance of fighter aircraft is always made by engineering the flow around the fuselage; one way is by the addition of a canard. The addition of a canard with delta configuration will bring about the appearance of a roll-up vortex, with a vortex core that has a speed higher than its free velocity, from the canard to the main wing. This vortex core, which keeps the flow above the main wing, remains streamlined and delays a stall, thus increasing the aircraft's maneuverability. The interaction of the vortex core from the canard with the airflow over the main wing is strongly influenced by the canard position against the main wing. Investigations needed to be done to see the effectiveness of the flow interactions. A visualization method using a water tunnel gave the advantages of a detailed flow review due to the density and mass diffusion being greater than air, yielding a better visualization. However, this suffered from limitations in getting quantitative data in detail, so that there was a need for computational fluid dynamics (CFD) techniques. The results of this study indicated the effectiveness of canard position on the flow interaction, having a good lift coefficient (Cl) for the canard position on the top and front side of the main wing, with the Cl increased by up to 5%-12.1%. While at a high angle of attack (AoA), the canard position that was closer or coincides with the wings was capable of delaying the stall to 5-10 deg of AoA. [ABSTRACT FROM AUTHOR]

The use of delta wings is widely used for high-speed aircraft such as fighter aircraft. In the delta wing, there is a pressure difference that causes the vortex flow and forms a vortex core with a very low pressure that will lead to the addition of lift force. Increased angle of attack will raise the vortex core speed so that the force will also rise, but under certain conditions, the vortex core structure will be destroyed, or there is a vortex breakdown that will remove the lift force. The analysis of the occurrence of vortex breakdown becomes very important to maintain lift force on the wing. Vortex breakdown analysis can be done through visualization techniques. The use of water tunnel as a visualization test facility has been widely used and has advantages in detail visualization. This research will be testing the character of vortex breakdown on delta wing by using GAMA water tunnel facility. For comparison and validation would be used computational fluid dynamics (CFD) technique. The results of the research show that the GAMA water tunnel facility can show the vortex breakdown phenomenon and the aerodynamic forces that occur on the delta wing. These results have conformity with the test using CFD and other references where the vortex breakdown was affected by the angle of attack and the change of the sweep angle. [ABSTRACT FROM AUTHOR]

This paper presents field performance measurement of a small scale 3-D wind turbine rotor blade design and a standard straight rotor blade design. The measurements were conducted at a point located 10 m from the shoreline in Yogyakarta, Indonesia. The rotors were mounted on a tower as high as 7 m. The rotors and an anemometer were installed at the same height and the distance between the anemometer and the tower is 4.5 m. Bin method with bin speed of 0.5 m/s is applied to analyze the recorded data.4th order polynomial trend line is used to characterize the calculated mean powers. The results show that 3-D wind turbine blade design yields higher power output and better performance than the standard blade design. [ABSTRACT FROM AUTHOR]