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GEOMETRIC MORPHOMETRIC BANANA LEAF MIDRIB AS WIND TURBINE AIRFOIL PROFILE Rosa, Firlya; Sutikno, Priyono; Suweca, I Wayan; Moelyadi, Mochammad Agoes
Jurnal Mekanova : Mekanikal, Inovasi dan Teknologi Vol 8, No 2 (2022): Oktober
Publisher : universitas teuku umar

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (26.898 KB) | DOI: 10.35308/jmkn.v8i2.6095

Abstract

Profil airfoil merupakan salah satu faktor yang mempengaruhi kinerja turbin angin sumbu horizontal. Sejumlah penelitian telah mengadopsi bentuk dan gerak binatang baik binatang air maupun binatang yang terbang. Anatomi alami pelepah daun pisang menjadi salah satu inspirasi untuk pemodelan profil airfoil. Profil pelepah dari tujuh sampel daun pisang dipetakan dengan menggunakan teknik morfometri geometrik berbasis landmark. Analisis sampel menggunakan metode statistik dan analisis aerodinamis airfoil menggunakan perangkat lunak QBLADE dengan perubahan bilangan Reynolds mulai dari 3E5 hingga 7E5 pada interval 1E5. Ada tujuh sampel dengan variasi profil dan variasi aerodinamis yang konstan. Dari hasil penelitian didapatkan bahwa semua model memiliki koefisien angkat tinggi, koefisien hambat rendah, dan glide ratio tinggi. Sampel 1 pada bilangan Reynolds 7E5 memiliki glide ratio tertinggi dengan nilai 123,07. Dari hasil analisa aerodinamis didapatkan bahwa dalam kondisi kecepatan angin rendah, profil airfoil berdasarkan morfologi pelepah pisang dapat diterima untuk turbin angin.
Simulasi Numerik Aeroelastik Model Seksional 2D Jembatan Bentang Panjang untuk Mengetahui Karakteristik Ketidakstabilan Flutter sulistiya, sulistiya; Moelyadi, Mochammad Agoes; Kusni, Muhammad; Akbar, Mahesa
MEDIA KOMUNIKASI TEKNIK SIPIL Volume 30, Nomor 1, JULI 2024
Publisher : Department of Civil Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/mkts.v30i1.52401

Abstract

Flutter is an aerodynamic instability on a long span bridge that can cause damage to the entire bridge deck structure. The interaction between wind and structure in long span bridges can be investigated by numerical simulation. In this study, an aeroelastic simulation was performed on a 2 DoFs sectional model of a long-span bridge deck with free vibration techniques to analyze flutter speed and determine the effect of deck shape on flutter instability characteristics using ANSYS software. The simulation result data was then extracted using the Modified Ibrahim Time-Domain Method (MITD) identification method to obtain the damping ratio and flutter derivatives coefficients. The damping ratio value is used to determine the critical flutter speed, whereas the coefficient flutter derivatives is used to determine the characteristics of flutter instability and the flutter mechanism that occurs in the bridge. The results showed that the rectangular shape (bluff body) is more susceptible to flutter instability than the streamlined shape, and has a lower flutter speed value than the other shapes. The flutter mechanism that occurs is torsional flutter, whereas in the streamline body is coupling flutter.
Velocity and wall shear stress of 18% EDTA irrigation solution flow in the removal of Ca(OH)2 with computational fluid dynamic analysis Muryani, Anna; Dharsono, Hendra Dian Adhita; Zuleika, Zuleika; Moelyadi, Mochammad Agoes; Fatriadi, Fajar
Padjadjaran Journal of Dentistry Vol 31, No 1 (2019): March 2019
Publisher : Faculty of Dentistry Universitas Padjadjaran

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (316.499 KB) | DOI: 10.24198/pjd.vol31no1.19280

Abstract

Introduction: Ethylene Diamine Tetra Acetic Acid (EDTA) 18% irrigation solution is one of the chelating agents that able to remove calcium hydroxide (Ca(OH)2) from the root canal wall. Failure of root canal treatment can be caused by the presence of residual calcium hydroxide in the root canal wall, thus blocking the bond between the medication and root canal filling material with the root canal wall. This study was aimed to observe the EDTA 18% flow in removing the Ca(OH)2 using CFD analysis. Methods: This research was descriptive. Cleanliness of the root canal wall from Ca(OH)2 medicament using EDTA 18% irrigation was analysed using the CFD method with test specimens in the form of resin blocks made according to the characteristics of the root canal. The irrigation needle used was side-vented with a position of 3 mm from the apical tooth. Stage analysis of root canal geometry was performed using Computational Fluid Dynamics (CFD) analysis to observe the characteristics of irrigation solutions in root canals in 3D. Results: The streamlined characteristics of EDTA 18% irrigation solution showed a unique behaviour due to the features of the side-vent shaped irrigation needle. Irrigation flow in the crown area of the inlet (side-vented irrigation needle) showed low velocity so that the fluid flow when exiting the inlet was more towards the apical than the outlet (root canal orifice). Conclusion: Velocity and wall shear stress of EDTA 18% showed the results validation conformity between experimental and CFD, that the maximum velocity of EDTA 18% is 19 ms-1 and EDTA 18% wall shear stress is 1.56 KPa for calcium hydroxide removal observed from the CFD study. Keywords: Computational fluid dynamics, EDTA 18%, calcium hydroxide (Ca(OH)2), velocity, wall shear stress