Search

Your search keyword '"Syariefatunnisa"' showing total 8 results
Start Over Author "Syariefatunnisa"
8 results on '"Syariefatunnisa"'

1. Pemodelan Numerik Aliran Angin di Sekitar Gedung Tinggi Menggunakan Metode RANS Standard K-ε dengan Program OpenFOAM

Author

Yongky Sanjaya, Doni Priambodo, Prasanti Widyasih Sarli, Herlien Dwiarti Setio, and Syariefatunnisa Syariefatunnisa

Subjects
cfd, openfoam, rans, domain komputasi, meshing, Engineering (General). Civil engineering (General), TA1-2040
Abstract

Beban angin di sekitar bangunan dapat mengalami amplifikasi yang mungkin menyebabkan kegagalan struktur, sehingga penting untuk memahami perilaku aliran fluida di antara bangunan. Dalam studi ini dilakukan pemodelan fluida dengan menggunakan RANS, sebuah metode computational fluid dynamics (CFD) yang memiliki waktu komputasi lebih cepat dari metode lain. Dalam studi ini digunakan program OpenFOAM yang merupakan program open source. Pemodelan dilakukan dengan menggunakan structured mesh dan untuk pemodelan turbulensi yang terjadi menggunakan metode RANS standard k-ε. Model dari kasus yang dipelajari merupakan 4 bangunan simetris dengan skala 1:420. Pemodelan numerik dilakukan dengan mengubah ukuran domain komputasi dan tingkat kehalusan meshing yang berbeda. Hasil penelitian menunjukkan domain komputasi memiliki pengaruh yang signifikan dalam melakukan CFD dimana nilai eror pada daerah aliran yang memiliki ratio kecepatan aliran yang tinggi ( >1) sehingga masuk dalam batasan eror yang dapat diterima. Sedangkan untuk perubahan tingkat meshing tidak memberikan perubahan eror yang signifikan, di mana dengan meshing relatif kasar dan memiliki waktu komputasi yang lebih cepat dapat menghasilkan hasil yang mirip dengan pemodelan yang menggunakan meshing lebih halus dan membutuhkan waktu komputasi yang besar.

Published
2022
Full Text
View/download PDF

2. Aeroelastic Optimization Using Laminate Fiber Orientation on a Composite Wing Structure

Author

Saputra, Angga Dwi, Satriya, Ilham Akbar A., Purabaya, R. Wibawa, Syariefatunnisa, Masfuri, Zuhdhy, Sangaji, Dimas, Ali, Farhan Muzzammil, Chaari, Fakher, Series Editor, Gherardini, Francesco, Series Editor, Ivanov, Vitalii, Series Editor, Haddar, Mohamed, Series Editor, Cavas-Martínez, Francisco, Editorial Board Member, di Mare, Francesca, Editorial Board Member, Kwon, Young W., Editorial Board Member, Trojanowska, Justyna, Editorial Board Member, Xu, Jinyang, Editorial Board Member, Nik Mohd., Nik Ahmad Ridhwan, editor, and Mat, Shabudin, editor

Published
2024
Full Text
View/download PDF

3. Numerical flutter analysis of composite wing structure on an unmanned aerial vehicle (UAV).

Author

Satriya, Ilham Akbar Adi, Saputra, Angga Dwi, Masfuri, Zuhdhy, Sangaji, Dimas, Muzzammil Ali, Farhan, Syariefatunnisa, and Purabaya, Raden Wibawa

Subjects
DRONE aircraft, COMPOSITE structures, NUMERICAL analysis, AIRPLANE wings, FLEXIBLE structures, COMPOSITE materials
Abstract

Wings on medium-altitude long-endurance (MALE) unmanned aerial vehicles (UAV) are lightweight with high aspect ratios and highly flexible. They may undergo large deformation. However, this can be improved using composite materials where the stiffness-to-weight ratio and structural stiffness of composite materials can be modified to optimize the flight envelope without compromising the aircraft's weight. Nevertheless, modern UAV design has brought new challenges for structural engineers. The increasing use of light and slender wings leads to structural configurations featuring low natural frequencies, which can easily experience aeroelastic instability. The most important aeroelastic phenomenon is flutter. Flutter is a dynamic instability of a flexible structure associated with the interaction of aerodynamic, elastic, and inertial forces and might cause potentially catastrophic failure. The main objective of this study is to identify the flutter boundary of the composite wing structure. An efficient computation approach and a detailed representation of the wing structural model are required to evaluate the wing structure's dynamic behavior accurately. The aeroelastic and structural analyses of the wing model are performed using MSC. Nastran/Patran. Following the results of the flutter analysis, the wing's structure can be stated that it is safe from the flutter phenomenon. Even though the flutter speed could not be found, the numerical analysis has been carried out exceeded the designed operational range, and there is no indication that the flutter would happen below two times the maximum diving speed. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

5. PENGUJIAN AERODINAMIKA TERHADAP MODEL UJI MASK OF CAR KERETA API DI INDONESIA LOW SPEED TUNNEL

Author

Gunawan Wijiatmoko and Syariefatunnisa Syariefatunnisa

Subjects
021103 operations research, 0211 other engineering and technologies, 020101 civil engineering, 02 engineering and technology, 0201 civil engineering
Abstract

Di dalam industri otomotif di dunia, produsen pasti menginginkan kendaraan yang aerodinamis sehingga irit dalam mengkomsumsi energi. Parameter aerodinamis ini dapat ditunjukkan secara kuantitatif melalui besaran gaya hambat. Demikian juga dengan industri kereta api. Pengujian Mask of Car Kereta api ini bertujuan untuk memvalidasi nilai dari koefisien gaya hambat dari salah satu bentuk Mask of Car kereta api yang sedang dalam tahap perancangan. Koefisien gaya hambat untuk benda berbentuk “bulk” seperti kereta api sekitar 1, sehingga diharapkan koefisien gaya hambat dari model uji yang diukur nilainya kurang dari 1. Model uji berupa model uji aerodinamika triple car skala 1:25 dengan Mask of Car di ujungnya. Pengujian dilakukan dengan meletakkan model uji di dalam seksi uji terowongan angin yang mempunyai penampang 4 m x 3 m, kemudian ditiup angin dengan kecepatan 44 m/s dengan variasi sudut (-) 45 derajat kurang dari sama dengan beta kurang dari sama dengan 45 derajat . Pengukuran gaya hambat dilakukan menggunakan internal balance, yang dipasang di bawah seksi uji. Di bawah model uji dipasang ground board untuk meminimalkan efek lapisan batas seksi uji. Hasil pengukuran menunjukkan koefisien gaya hambat dari mask of car yang dirancang adalah 0.84.

Published
2020
Full Text
View/download PDF

7. Kajian Eksperimental Soft Flutter Pada Model Seksional Jembatan

Author

Saputra, Angga Dwi and Syariefatunnisa, Syariefatunnisa

Abstract

Aeroelastic testing of a sectional bridge model in a wind tunnel with scale 1:20 had been conducted. The model was tested to study the characterictis of aeroelastics dynamic, such as Vortex Induced Vibration (VIV) and flutter. Based on the testing, phenomenon soft flutter was found in the test. Soft flutter has different characteristics as classical or hard flutter. In hard flutter, there are obvious divergence point, which is the point of wind speed when the amplitude increases suddenly and might be catastrophic. In soft flutter phenomenon, the vibration amplitude increases gradually as increasing of wind speed. In this paper, the characteristics of soft flutter on a model will be described and the method to determine its critical flutter speed.Keywords: Aeroelastic, flutter, divergence, critical flutter speedAbstrakPengujian aeroelastika di terowongan angin pada model seksional jembatan dengan skala 1:20 dilakukan untuk mengetahui karakteristik aeroelastika dinamik, yaitu Vortex Induced Vibration (VIV) dan flutter. Berdasarkan hasil pengujian terlihat fenomena flutter yang terjadi adalah soft flutter. Fenomena soft flutter berbeda dengan classical flutter atau hard flutter, dimana pada hard flutter terdapat titik divergen yang jelas. Pada hard flutter titik divergen ditandai dengan naiknya amplitudo menjadi sangat besar secara tiba-tiba dan dapat mengakibatkan kerusakan yang fatal. Pada soft flutter amplitudo getaran akan meningkat secara bertahap dengan bertambahnya kecepatan angin. Makalah membahas karakteristik soft flutter yang terjadi dan metode untuk menentukan kecepatan kritis flutter.Kata kunci : Aeroelastika, flutter, divergen, kecepatan kritis flutter

Published
2018

8. Wind Tunnel Test of Musi VI Bridge.

Author

Permata, Robby, Andika, Matza Gusto, Syariefatunnisa, Risdhiawan, Eri, Hermawan, Budi, and Noordiana, Indra

Subjects
IRON & steel bridges, TESTING of wind tunnels, FINITE element method, VIBRATION (Mechanics), AERODYNAMICS
Abstract

Musi VI Bridge is planned to cross the Musi River in Palembang City, South Sumatera Province, Indonesia. The main span is a steel arch type with 200 m length and side span length is 75 m. Finite element analysis results showed that the bridge has frequency ratio for torsional and heaving mode (torsional frequency/heaving frequency) = 1.14. This close to unity value rises concern about aerodynamic behaviour and stability of the bridge deck under wind loading. Sectional static and free vibration wind tunnel test were performed to clarify this phenomena in B2TA3 facility in Serpong, Indonesia. The test followed the draft of Guide of Wind Tunnel Test for Bridges developed by Indonesian Ministry of Public Works. Results from wind tunnel testing show that the bridge is safe from flutter instability and no coupled motion vibration observed. Therefore, low value of frequency ratio has no effect to aerodynamic behaviour of the bridge deck. Vortex-induced vibration in heaving mode occurred in relatively low wind velocity with permissible maximum amplitude value. [ABSTRACT FROM AUTHOR]

Published
2017
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results