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Leading Edge Modification of NACA 0015 and NACA 4415 Inspired by Beluga Whale James Julian; Waridho Iskandar; Fitri Wahyuni
International Journal of Marine Engineering Innovation and Research Vol. 8 No. 2 (2023)
Publisher : Department of Marine Engineering, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25481479.v8i2.5447

Abstract

This research modifies the leading-edge structure of NACA 0015 and NACA 4415 to resemble the nose of a beluga whale. The focus of this modification is to improve the airfoil's aerodynamic performance and investigate the changing fluid flow patterns. Numerical equation used is RANS combined with the k-epsilon turbulence model. Mesh independence test shows that mesh with 200 elements is the best mesh. Validation results reveal that CFD data can follow the trend of experimental data, especially on the AoA before the stall. There was a significant increase in Cl from NACA 0015 and NACA 4415 at AoA>9°. On the other hand, the modification also had a positive effect by lowering the Cd value. The modification also provides an advantage by increasing the maximum Cl/Cd value. Furthermore, the separation point data shows that the modification can delay the separation of the fluid flow in the airfoil. Modifications can cause an increase in pressure on the lower side and a decrease in pressure on the upper side. Through velocity contours and streamlines, the modifications can reduce the recirculation area. Overall, modifying the leading edge has positive impacts on the NACA 0015 and NACA 4415 airfoils.
Aerodynamics Improvement of NACA 0015 by Using Co-Flow Jet James Julian; Waridho Iskandar; Fitri Wahyuni
International Journal of Marine Engineering Innovation and Research Vol. 7 No. 4 (2022)
Publisher : Department of Marine Engineering, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25481479.v7i4.5557

Abstract

This study analyzes co-flow as active flow control in the object of the airfoil. NACA 0015 is the airfoil used in this study. The airfoil was then modified to add co-flow jet features. Co-flow jet was placed on the upper chamber to analyze its effect on airfoil performance. Further, the Co-flow jet was studied by varying the injected mass flow rate () in the injection slot. The variation of is 0.15, 0.20, and 0.25 kg/s. The study used CFD with the governing equation RANS. Reynolds Averaged Navier Stokes combined with turbulence model to solve all equations. Two equations for the turbulence model are used in this study. Specifically, this study discusses the aerodynamics of the airfoil, i.e., lift force, drag force, and fluid flow visualization, such as pressure contour and velocity contour. Co-flow jets can improve the aerodynamics of airfoils. The bigger the injected, the higher the lift coefficient increases. On the other hand, the drag force will be reduced as the number of injected fluid flow increases. Because of that, the airfoil efficiency will be better if using a co-flow jet. However, the Cl/Cdcurve peak shifts to smaller as the injection fluid flow are bigger. The fluid flow visualization by velocity contour on AoA=20° revealed that the co-flow jet could overcome separation.
Effect of Single Slat and Double Slat on Aerodynamic Performance of NACA 4415 James Julian; Waridho Iskandar; Fitri Wahyuni; Armansyah; Ferdyanto
International Journal of Marine Engineering Innovation and Research Vol. 7 No. 2 (2022)
Publisher : Department of Marine Engineering, Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25481479.v7i2.5626

Abstract

This study uses a Computational Fluid Dynamics (CFD) approach. The main object in this study is NACA 4415 with slat variations. The airfoil used as the slat is Eppler 421. Reynolds number in this study is 3Í106. This study uses an unstructured mesh with a triangular cell shape with 137824 elements. The use of slats can improve the aerodynamic performance of NACA 4415. NACA 4415 without slat stalled at AoA=16º. Stall on airfoils with a single slat and double slat occurred at AoA=20º. Slat can increase Cl in NACA 4415; however, the difference in Cl increase is not much different when using a single slat or double slat. An airfoil with a single slat, on average, can increase Cl by 20.9129%. The average increase in Cl for an airfoil with a double slat is 25.6878%. Single slat and double slat increase Cd. A single slat increased Cd with an average increase of 26.1109%, and the average increase in Cd for airfoils with double slat was 54.6152%. Single slat can produce a better Cl to Cd ratio than double slat, but the optimum AoA of double slat is 1º higher than single slat. Visualization of fluid flow at AoA=16° shows the fluid flow separation in the airfoil without a slat. The fluid flow separation can be handled well when NACA 4415 is given a single slat or double slat.