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COMPUTATIONAL FLUID DYNAMICS ANALYSIS BASED ON THE FLUID FLOW SEPARATION POINT ON THE UPPER SIDE OF THE NACA 0015 AIRFOIL WITH THE COEFFICIENT OF FRICTION James Julian; Waridho Iskandar; Fitri Wahyuni; Ferdyanto Ferdyanto
Media Mesin: Majalah Teknik Mesin Vol 23, No 2 (2022)
Publisher : Program Studi Teknik Mesin, Universitas Muhammadiyah Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23917/mesin.v23i2.18217

Abstract

A new method that is more practical, efficient and applicable is proposed to track the position of fluid flow separation on the upper side of NACA 0015. The proposed method is the coefficient of friction curve (Cf) method on the airfoil's upper side. The approach used is a computational fluid dynamics (CFD) approach. The governing equation used is the Reynolds Averaged Navier-Stokes (RANS) equation.  is the turbulence model implemented in this study. The research is conducted on the low Reynolds number category. The low Reynolds number is in the range of values from 104 to 3Í105. Cf can predict the location of fluid flow separation more practically, efficiently, and applicable than the fluid flow velocity profile method. Flow separation begins to form at  =8° at position x/c=0.8. The location of the fluid flow separation continues to move closer to the leading edge as the  airfoil increases. Through the Cf curve, the location of the fluid flow separation is when the Cf curve experiences a sudden decrease and approaches the x-axis. If the separation points are described in the form of velocity profiles and fluid flow velocity contours, it will form an extreme decrease.
Effect of Single Slat and Double Slat on Aerodynamic Performance of NACA 4415 James Julian; Waridho Iskandar; Fitri Wahyuni; Armansyah Armansyah; Ferdyanto Ferdyanto
International Journal of Marine Engineering Innovation and Research Vol 7, No 2 (2022)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1410.49 KB) | DOI: 10.12962/j25481479.v7i2.12875

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.
Characterization of the Co-Flow Jet Effect as One of the Flow Control Devices James Julian; Waridho Iskandar; Fitri Wahyuni; Ferdyanto; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa & Inovasi Volume 4 Nomor 2 Tahun 2022
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v4i1.3437

Abstract

The computational study discusses the application of the co-flow jet technique as a fluid flow control device on the NACA 0015 airfoil. The numerical equation used is the RANS equation with the k-ε turbulence model. There are three variations of the mesh proposed in this paper. The first variation is a fine mesh with 100,000 elements. The second variation is a medium mesh with 50,000 elements. Meanwhile, the third variation is coarse mesh with 25,000 elements. Based on the mesh independence test results, the mesh with the lowest error value is the fine mesh. Co-flow jet is proven to control fluid flow on the upper side of NACA 0015. Co-flow jet can also improve the aerodynamic performance of NACA 0015 by increasing Cl and decreasing Cd. The increase in Cl was 114% and the decrease in Cd was 24%. The fluid flow separation on the upper side of the airfoil can also be handled well by the co-flow jet.
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 : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25481479.v7i4.14898

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. 
The effect of curvature ratio towards the fluid flow characteristics in bend pipe based on numerical methods James Julian; Fitri Wahyuni; Waridho Iskandar; Rifqi Ramadhani
TURBO [Tulisan Riset Berbasis Online] Vol 12, No 1 (2023): Jurnal TURBO
Publisher : Universitas Muhammadiyah Metro

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24127/trb.v12i1.2564

Abstract

Internal flows in pipes are studied in greater depth and comprehensiveness in research. The computation done by using RANS equation. In particular, this study uses two equations turbulence model which is k-ε turbulence model. Mesh with 2×106 element is used because it is a mesh with lowest error. The research focuses on the effect of the curvature ratio (Rc) at the bend on changes in fluid flow characteristics. The Rc variations chosen in this study were 0.01, 0.02, and 0.03. The pipe diameter is 0.01 m, resulting in Rc/D=1, Rc/D=2, and Rc/D=3. At Rc/D=1, the maximum fluid flow velocity is in an area closer to the inner core than the outer core. The fluid velocity distribution is also more even if Rc/D=1 is enlarged. The fluid flow separation appears in the pipe with Rc/D=1, but the fluid flow separation in Rc/D=2 and Rc/D=3 is not visible. The separation is at α=75.96º, while the reattachment location is at x/D=0.014.
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 : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25481479.v8i2.16432

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-ε 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.
Aerodynamic Performance Improvement on NACA 4415 Airfoil by Using Cavity James Julian; Waridho Iskandar; Fitri Wahyuni; Nely Toding Bunga
Jurnal Asiimetrik: Jurnal Ilmiah Rekayasa Dan Inovasi Volume 5 Nomor 1 Tahun 2023
Publisher : Fakultas Teknik Universitas Pancasila

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35814/asiimetrik.v5i1.4259

Abstract

This study uses a numerical method to analyze the cavity's use on the airfoil's trailing edge and the aerodynamic effects it generates. The type of airfoil used is NACA 4415. The variations in the Reynolds number examined in this study are 2×105 and 3×105. The governing equation is the Reynolds Averaged Navier-Stokes paired with the k-ε turbulence model. This study concludes that the cavity can increase Cl in the airfoil but cannot delay the stall. The increase in Cd is also a negative effect of using a cavity in the airfoil. The cavity can increase Cl by increasing the pressure on the lower side near the trailing edge. Meanwhile, the cavity increases Cd because it creates a separation of the fluid flow, forming a vortex when viewed in a streamlined form of fluid flow.
ANALYSIS OF AERODYNAMIC PERFORMANCE OF EROSION AIRFOIL WITH REYNOLDS NUMBER VARIATIONS James Julian; Waridho Iskandar; Fitri Wahyuni
Jurnal Ilmiah Teknologi dan Rekayasa Vol 28, No 2 (2023)
Publisher : Universitas Gunadarma

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35760/tr.2023.v28i2.8299

Abstract

Erosion on airfoil was investigated using computational methods to investigate changes in the performance of the airfoil. NACA 0015 used in this study has a chord length of 1 m, which is then used as a parameter in calculating the Reynolds number. The computational process is carried out with domain C with dimensions that have been arranged in such a way as to avoid the influence of the boundary on the computational results obtained in this study. The governing equation for this study is RANS which the standard k-ω turbulence model supports. Erosion has a considerable influence on changes in the aerodynamic performance of the airfoil. Erosion can significantly reduce the Cl value of the airfoil, especially at high AoA. Erosion of the airfoil results in an increase in the value of Cd. The increase in Cl value can be explained by visualizing the pressure contour around the airfoil. The pressure contour shows a decrease in pressure in the lower but an increase in the upper. The velocity and streamline contours can explain the cause of the increase in Cd, which is very clearly caused by the separation in the erosion area and on the upper surface of the airfoil.
HYDRODYNAMICS ANALYSIS OF JANUS SPHERE AT VARIATIONS OF THE REYNOLDS NUMBER James Julian; Waridho Iskandar; Fitri Wahyuni
Jurnal Teknologi Vol 15, No 2 (2023): Jurnal Teknologi
Publisher : Fakultas Teknik Universitas Muhammadiyah Jakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24853/jurtek.15.2.315-324

Abstract

The hydrodynamics of the homogeneous and Janus spheres were compared computationally at various Reynolds number variations. The Janus sphere is divided into two parts: slippery, which is set as a free-slip wall, and sticky, which is arranged as a free-slip wall. The equation used is the RANS equation for laminar fluid flow. Research focuses more on hydrodynamic forces and visualization of fluid flow by using velocity contours and streamlines. The domains of computational processes are arranged in a rectangular shape. The Richardson Extrapolation method verifies the mesh and gives the result that the meh variation is within the convergence range. Mesh with 105 elements is used for further computation because it only gives the lowest error of 0.129%. Meanwhile, the validation results show that the computational process can follow the experimental results at 0°≤θ≤80°. The Janus sphere is hydrodynamically better than the homogeneous sphere, where the Cl produced is larger and the Cd produced is smaller. The Janus sphere can prevent separation at a Reynolds number of 20 and reduce the recirculation area at a Reynolds number of 50.
The Influence of Mounting Angle on Gurney Flap on The Aerodynamics Performance of NACA 0015 Using CFD Method Mirza Fauzan Lukiano; James Julian; Fitri Wahyuni; Waridho Iskandar
International Journal of Marine Engineering Innovation and Research Vol 8, No 4 (2023)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j25481479.v8i4.18891

Abstract

Improving the airfoil aerodynamics is quite an essential aspect of the aviation industry. One method for improving airfoil aerodynamics involves applying passive flow control techniques. The effect of using the gurney flap as passive flow control was explored through the CFD approach with the RANS control equation and incorporating k-epsilon as a turbulence model. The airfoil model utilized in this study was the NACA 0015 airfoil operating at a Reynolds number of 1×106. This study explored three different mounting angles of the gurney flap, namely 45°, 60°, and 90°. The outcomes show that adding the gurney flap has positive results in increasing the lift and drag of the NACA 0015. An airfoil with a mounting angle flap of 45° has an average percentage increase in Cl of 23%, followed by a mounting angle flap of 60°, which is 28%, and a percentage Cl of 45% for a mounting angle flap of 90°. Meanwhile, Gurney flaps with a mounting angle of 45° can increase Cd by an average percentage of 3%, while mounting angle flap at 60° increases the Cd percentage by 4% and 5% for a mounting angle of 90°. Moreover, fluid flow visualization with pressure and velocity contours was given at AoA 10º to determine its effect on increasing lift and drag on the NACA 0015 airfoil.