Claim Missing Document
Check
Articles

Found 5 Documents
Search

Fenomena Kontrol Aliran Secara Pasif Pada Konfigurasi Ahmed Body Menggunakan Segitiga Kendali Yamin, Mohamad; Nashirudin, Hamzah Ali; Firmansyah, Riyan
AME (Aplikasi Mekanika dan Energi): Jurnal Ilmiah Teknik Mesin Vol. 10 No. 2 (2024)
Publisher : Universitas Ibn Khaldun Bogor

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Penelitian ini melibatkan analisis numerik aliran dengan pengendalian pasif menggunakan segitiga kendali pada Ahmed Body dengan sudut kemiringan 25⁰. Ahmed Body adalah model standar yang sering digunakan dalam studi aerodinamika untuk mensimulasikan aliran udara di sekitar kendaraan. Salah satu tantangan utama dalam aerodinamika otomotif adalah mereduksi gaya hambat (drag) yang dapat meningkatkan efisiensi bahan bakar dan performa kendaraan. Tujuan penelitian ini adalah untuk mereduksi drag aerodinamik dengan pendekatan pengendalian aliran pasif. Pendekatan ini menggunakan segitiga kendali yang belum pernah diterapkan sebelumnya, dimana segitiga kendali dengan sisi hipotenusa 20 mm, adjacent 8,45 mm, dan opposite 18,13 mm diletakkan pada posisi tak berdimensi x/c = 0. Penelitian ini merupakan contoh baru dalam penerapan pengendalian aliran pasif pada Ahmed Body. Penelitian ini diselesaikan menggunakan metode Computational Fluid Dynamics (CFD) dengan model turbulensi k-ꞷ SST dan software ANSYS FLUENT  untuk menganalisis fenomena aliran turbulen. Validasi dilakukan dengan membandingkan hasil numerik pada model baseline dengan data eksperimen yang telah dilaporkan dalam literatur. Hasilnya disajikan secara visual dalam bentuk gambar dan nilai koefisien drag. Hasil penelitian menunjukkan bahwa segitiga kendali mampu mengurangi drag secara signifikan sebesar 5,07%. Visualisasi aliran menunjukkan bahwa segitiga kendali berhasil memanipulasi aliran wake di belakang Ahmed Body, mengurangi tekanan negatif dan drag.
2D CFD Simulation on the Aerodynamic Performance Enhancement of H-Darrieus VAWT Utilized with Flaps Yamin, Mohamad; Putra, Andrian; Firmansyah, Riyan
Engineering Science Letter Vol. 3 No. 03 (2024): Engineering Science Letter
Publisher : The Indonesian Institute of Science and Technology Research

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56741/esl.v3i03.564

Abstract

This research aims to enhance the aerodynamic performance of the H-Darrieus Vertical Axis Wind Turbine (VAWT) consisting of 3 main blades with the addition of flaps on each blade. Performance evaluation and geometry optimization are conducted by varying the gap distance between the main blades and flaps and altering the deflection angle of the flaps. A numerical approach using Computational Fluid Dynamics (CFD) is employed to analyze the performance of VAWT turbines and optimize the gap distance between the blades and flaps. NACA 0018 profiles are utilized for the main blades, while NACA 0015 profiles are used for the flaps. A two-dimensional CFD model of the VAWT turbine is analyzed using the Unsteady Reynolds Averaged Navier-Stokes (URANS) method with the k-ω Shear Stress Transport (SST k-ω) turbulence model. Simulations are conducted using ANSYS Fluent software, encompassing turbine models with and without flaps—validation of simulation results for turbines with and without flaps through experimental and numerical approaches. Simulation variations with flaps are carried out by considering the parameter of gap distance between the blades and flaps at various Tip Speed Ratio (TSR) values. The research results indicate an optimal distance between the main blades and flaps at a specific flap deflection angle where the power coefficient reaches its maximum value. Overall, the addition of flaps and deflection angle variations positively contribute to the aerodynamic performance of VAWT turbines.
HUBUNGAN TINGKAT PENGETAHUAN PATIENT SAFETY TERHADAP SIKAP PATIENT SAFETY PADA TENAGA KESEHATAN DI RUANG OPERASI RS PKU MUHAMMADIYAH GAMPING Firmansyah, Riyan; Tri Hapsari Listyaningrum
Jurnal Kesehatan Masyarakat Indonesia (JKMI) Vol. 2 No. 1 (2024): Oktober
Publisher : Publikasi Inspirasi Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.62017/jkmi.v2i1.2258

Abstract

Keselamatan pasien (patient safety) adalah dasar dari pelayanan kesehatan yang baik. Keselamatan pasien juga menjadi salah satu indikator dalam menilai akreditas institusi pelayanan kesehatan, oleh karena itu keselamatan pasien sangat penting. Namun, jika ditinjau dari insiden keselamatan pasien, keselamatan pasien di berbagai tingkat pelayanan kesehatan masih buruk, baik secara global maupun nasional. Penelitian ini untuk mengetahui Hubungan Tingkat Pengetahuan Patient Safety Terhadap Sikap Patient Safety Pada Tenaga Kesehatan di Ruang Operasi RS PKU Muhammadiyah Gamping.  Penelitian ini menggunakan metode kuantitatif dengan desain korelasi, yaitu penelitian hubungan antara dua variabel. Teknik pengambilan sampel menggunakan total sampling, berjumlah 30 responden. Alat yang digunakan dalam pengumpulan data berupa kuesioner analisis data menggunakan uji statistik spearman rank. Penelitian ini menunjukan hasil uji korelasi yang positif hasil uji korelasi yang telah dilakukan, diketahui bahwa nilai signifikansi atau Sig (2-tailed) ialah sebesar 0,000< 0,05 dengan nilai koefisien sebesar 0.711**. Ada hubungan pengetahuan patient safety dengan sikap patient safety pada tenaga kesehatan di ruang operasi RS PKU Muhammadiyah Gamping.
Handling and Stability Analysis of an Autonomous Vehicle Using Model Predictive Control in a CarSim–Simulink Co-Simulation Environment Yamin, Mohamad; Mumtaz, Mega Maulida; Firmansyah, Riyan
International Journal of Innovation in Mechanical Engineering and Advanced Materials Vol 7, No 2 (2025)
Publisher : Universitas Mercu Buana

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22441/ijimeam.v7i2.31812

Abstract

Cars are a prevalent mode of transportation for both people and goods, with B-class hatchbacks being particularly popular in Indonesia. However, road traffic crashes remain a major concern, contributing millions of deaths annually, primarily due to human error. Autonomous vehicles offer a promising solution to mitigate these issues by reducing reliance on human control. In particular, Level 3 autonomous vehicles enhance road safety, enable independent mobility, reduce traffic congestion, and allow drivers to engage in non-driving tasks. This study proposes an autonomous vehicle model that employs a trajectory tracking approach using Model Predictive Control (MPC), a robust and widely adopted control strategy in autonomous systems. A three-degree-of-freedom (3-DOF) vehicle dynamic model was developed and analyzed through co-simulation using CarSim and Simulink to evaluate its performance during a double-lane change maneuver. The simulation results demonstrate that the vehicle accurately follows the reference trajectory and exhibits excellent dynamic performance. The roll angle remained consistently low, ranging between 0.024 and 0.026 radians—well below the rollover threshold of 0.14 radians—demonstrating strong roll stability. The slip angle varied between –0.013 and 0.0135 radians, nearly 12 times lower than the critical limit, indicating optimal traction and directional control. Lateral acceleration ranged from –3.59 m/s² to 3.41 m/s², and yaw rate remained within –7.78°/s to 7.25°/s, both well within safe operational bounds. These findings confirm that the proposed MPC-based control framework enables precise path tracking, robust stability, and reliable handling performance in dynamic driving scenarios.
PRESTASI POMPA SENTRIFUGAL TIPE OVERHUNG UNTUK APLIKASI INDUSTRI DENGAN METODE REVERSE ENGINEERING DAN CFD Yamin, Mohamad; Irawan, Rudi; Mahandari, Cokorda Prapti; Ariandi, Rian Dwi; Firmansyah, Riyan; Alfasha, Muhammad Zidan; Suharto, Suharto
Machine : Jurnal Teknik Mesin Vol 11 No 1 (2025): Machine : Jurnal Teknik Mesin
Publisher : Jurusan Teknik Mesin Fakultas Sains dan Teknik Universitas Bangka Belitung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33019/jm.v11i1.5623

Abstract

Indonesia faces various challenges in achieving net zero emissions, energy crises, and urgent agricultural irrigation needs. In this context, centrifugal pumps play a crucial role in various industrial applications and irrigation systems. However, performance curve data for pumps is often unavailable, particularly for older pumps or those with lost documentation. This study aims to develop new performance curves for centrifugal pumps using Reverse Engineering (RE) based on 3D scanning and Computational Fluid Dynamics (CFD) simulation. The process begins with geometric modeling of the pump using 3D scanning to obtain accurate data regarding the pump’s physical shape. The model is then used in CFD simulations with the k-epsilon (k-ε) turbulence model and SIMPLE method to analyze flow characteristics and pump performance. Simulation results show that the deviation in efficiency and power compared to existing experimental data is below 2%, with a mesh size of 0.00005 mm providing optimal results in terms of accuracy and computational efficiency. This research demonstrates that developing performance curves using RE and CFD methods can address issues of missing data and provide a solid foundation for design improvements and efficient operation of centrifugal pumps. The findings have the potential to enhance operational efficiency of pump systems and support environmental impact mitigation efforts through pump technology optimization.