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SHOCKWAVE STUDY ON THE WINGS NACA 0012, NACA 64 - 206, AND NASA SC (2) - 0706 WITH Λ = 15O AT 0.85 MACH NUMBER Dewi Puspitasari; Kasyful Warist Kiat
Indonesian Journal of Engineering and Science (IJES) Vol. 2 No. 1 (2021): Table of Contents
Publisher : Asosiasi Peneliti Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51630/ijes.v2i1.10

Abstract

Airfoil is used as a basic form on aircraft wings. Airfoil on the wing of the aircraft is used to produce lift that will lift the fuselage into the air. Lifting force results from the difference in pressure between the upper surface and the lower surface of an aircraft wings. In high speed flights shockwave will occur at certain parts of the wing which will adversely affect the aerodynamic performance of the wing. Wing aerodynamic performance at high speeds can be improved in various ways, one of which is by giving a angle to the wing span called a swept angle. This study will use 3D CFD simulation methods using Ansys Fluent. The airfoil used are NACA 0012, NACA 64-206, and NASA SC (2) -0706 with a chord length of 1 m, AR = 5, and λ = 1 with backward swept angle Λ = 15 °. Free stream flow is air flowing with Mach Number = 0,85 at sea level and steady conditions. Based on the simulation results, shock occurs on the upper and lower surfaces for NACA 0012 with Cl = 0 due to symmetric airfoil, whereas shock occurs only on the upper surface for NACA 64-206 and NASA SC (2) - 0706 with a Cl / Cd value of 18.55 ( NACA 64-206) and 20.78 (NASA SC (2) - 0706). This simulation also provides a visual representation of Mach Number contour plots in the middle stretch (Midspan) of the wing and Cl and Cd data.
The Effect of Argon Flow Rate on Mechanical Properties and Microstructures in Titanium Welding Dewi Puspita Sari; Amir Arifin; Gunawan Gunawan; Dendy Adanta; Ihsan Asura; Imam Syofii
JEMMME (Journal of Energy, Mechanical, Material, and Manufacturing Engineering) Vol. 6 No. 3 (2021): In Progress
Publisher : University of Muhammadiyah Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22219/jemmme.v6i3.19082

Abstract

In the past of developing technology, the need for welding techniques to connect the structures of the component is increasing, especially tungsten inert gas (TIG). Several factors are considered in selecting material to be welded: toughness, density, and corrosion resistance. Titanium is a metal with a low density, has good heat transfer, and high melting point hence widely used for various purposes, such as petrochemicals, spacecraft, medical devices, and reactors. However, the titanium welding process is difficult because no absence of protection against air during the welding process results in high absorption of oxygen from free air (which causes carbon and hydrogen contamination). As a result, the mechanical properties quality of commercially pure titanium decreases. The main parameters of TIG welding to overcome high absorption of oxygen are arc length, welding current, welding travel speed, and flow rate of shielding gas (argon). For this case, this study investigates the effect of argon flow rate on mechanical properties and microstructures in titanium welding. Based on the results, the argon flow rate significantly affects the welding results; a high argon flow rate protects the welding from oxygen so that the hardness is not too high increased compared to low flow rates. Furthermore, it increases the hardness and decreases the strength of the material and ductility when fractured. Based on metallographic testing, the main metal area of commercially pure titanium has a uniform grain size with a hexagonal closed packed (HCP) phase. In contrast, the grain forms become elongated like straw, called platelet and acicular alpha in the HAZ and weld metal.
Application of Computational Fluid Dynamics Method for Cross-flow Turbine in Pico Scale Imam Syofi'i; Dendy Adanta; Aji Putro Prakoso; Dewi Puspita Sari
JEMMME (Journal of Energy, Mechanical, Material, and Manufacturing Engineering) Vol. 6 No. 1 (2021)
Publisher : University of Muhammadiyah Malang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22219/jemmme.v6i1.12813

Abstract

Crisis electricity was a crucial issue in the rural area. Crossflow turbine (CFT) in pico in pico scale is the best option for electricity provider for rural areas. Due to its usefulness and development of computer technology, computational fluid dynamics method application for CFT study becomes increasingly frequent. This paper compiles the implementation of the computational fluid dynamic (CFD) approach for CFT on a pico scale. Based on the literature, the Renormalization Group (RNG)  turbulence model is recommended to predict the flow field that occurs in CFT because its error is lower than others turbulence models, the RNG  error of 3.08%, standard  of 3.19%, and transitional SST of 3.10%. Furthermore, six-degrees of freedom (6-DoF) is recommended because it has an error of 3.1% than a moving mesh of 9.5% for the unsteady approach. Thus, based on the review, the RNG  turbulence model and 6-DoF are recommended for the CFT on the pico scale.
Pengembangan Modul Elektronik Berbasis Website Mobile Friendly pada Mata Kuliah Elemen Mesin Dewi Puspita Sari; Darlius; Harlin
Jurnal Rekayasa Mesin Vol. 20 No. 1 (2020): Jurnal Rekayasa Mesin
Publisher : Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36706/jrm.v20i1.209

Abstract

Studi ini bertujuan untuk menghasilkan media pembelajaran berupa modul elektronik mata kuliah Elemen Mesin berbasis website mobile friendly yang valid, praktis dan efektif. Metode pengembangan yang digunakan adalah Model FourD. Model FourD dipilih karena memiliki tahapan yang lebih lengkap dibandingkan model lainnya. Berdasarkan hasil, penilaian materi dan media modul masing-masing sebesar 92% dan 93%, dimana ini dikategorikan valid. Lebih lanjut, berdasarkan hasil one to one, small group dan field test, modul elektronik Elemen Mesin ini dikategorikan praktis. Efektivitas modul dan materinya diuji dan dianalisis menggunakan standar gain. Hasil perhitungan menggunakan standar gain, modul dan materinya adalah efektif. Dengan demikian, modul dan materinya dapat dikatakan valid, praktis dan efektif untuk digunakan.
HISTORY OF UTILIZATION OF THE COMPUTATIONAL FLUID DYNAMICS METHOD FOR STUDY PICO HYDRO TYPE CROSS-FLOW Dendy Adanta; Dewi Puspita Sari; Nura Muaz Muhammad; Aji Putro Prakoso
Indonesian Journal of Engineering and Science (IJES) Vol. 2 No. 1 (2021): Table of Contents
Publisher : Asosiasi Peneliti Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.51630/ijes.v2i1.11

Abstract

Energy crisis in particular, electricity in the isolated rural areas of Indonesia is a very crucial issue that needs to be resolve through electrification . Compared to other options, pico hydro cross-flow turbine (CFT) is the better option to provides electrical power for the isolated rural areas. Studies to improve CFT performance can be undertaken analytically, numerically, experimentally, or a combination of those methods. However, the development of computer technology makes numerical simulation studies have become increasingly frequent. This paper describes the utilization of the computational fluid dynamic (CFD) approach in the pico hydro CFT method. This review has resulted that the recommended Renormalization Group (RNG) k-ε turbulence model for CFT CFD simulation because its absolute relative error is lower than standard k-ε and transitional Shear Stress Transport (SST). The absolute relative error for the RNG k-ε turbulence model of 3.08%, standard k-ε of 3.19%, and transitional SST of 3.10%. While for the unsteady approach, the six-degrees of freedom (6-DoF) are considered because more accurate than moving mesh. The absolute relative error for 6-DoF of 3.1% and moving mesh of 9.5%. Thus, based on the review, the RNG k-ε turbulence model and 6-DoF are proposed for the pico hydro CFT CFD study.
PRODUCTION OF BIOGAS BASED ON HUMAN FESSES AS AN ALTERNATIVE ENERGY FOR REMOTE AREAS APPLICATION Imam Syofii; Dewi Puspita Sari
Indonesian Journal of Engineering and Science (IJES) Vol. 3 No. 1 (2022): Table of Contents
Publisher : Asosiasi Peneliti Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (371.007 KB) | DOI: 10.51630/ijes.v3i1.29

Abstract

The utilise of biogas for remote areas is a problem because it is challenging to supply hydrogen. Hence a study of the utilisation of human fesses as biogas raw material for biogas production is proposed. Due to high investment costs to build miniature power plants, modified gasoline engines are used as mini power plants even though it is a laboratory scale. Based on results, human fesses can be used as raw material for biogas production. Performance engine using biogas derived from human fesses is 9% different from LPG. The maximum efficiency of the biogas system is 32%, and that of the LPG is 41%.