Studi Numerik Optimasi Analisis Aerodinamika dengan Memvariasikan Jumlah Grid dan kecepatan

Thatip Nur Khafid; Hisyam Ma’mun; Muhammad Syafii

Authors

Thatip Nur Khafid Universitas Persatuan Guru Republik Indonesia
Hisyam Ma’mun Universitas Persatuan Guru Republik Indonesia
Muhammad Syafii Universitas Persatuan Guru Republik Indonesia

Keywords:

Computational Fluid Dynamics (CFD), Distribusi Tekanan, Aerodinamis, Drag Force, Lift Force, Grid Independence

Abstract

Penelitian ini menganalisis karakteristik aerodinamika bus menggunakan simulasi Computational Fluid Dynamics (CFD) melalui variasi jumlah grid dan variasi kecepatan aliran. Uji independensi grid dilakukan pada kecepatan 100 km/jam dengan jumlah grid 500.000, 1.000.000, 1.500.000, dan 2.000.000 sel untuk mengevaluasi kestabilan koefisien aerodinamika. Hasil uji menunjukkan koefisien drag (Cd) menurun dari 0,943 pada grid 500 menjadi 0,743 pada grid 2.000.000, sedangkan koefisien lift (Cl) relatif stabil pada rentang 0,118–0,127, sehingga grid 2.000.000 dipilih untuk simulasi lanjutan. Validasi numerik terhadap data eksperimen pada variasi kecepatan 100–140 km/jam menunjukkan Cd numerik berada pada rentang 0,703–0,743, sementara Cd eksperimen berada pada rentang 0,608–0,664. Nilai Cl numerik berada pada rentang 0,121–0,127, sedangkan Cl eksperimen berada pada rentang 0,107–0,112. Secara umum, hasil simulasi menghasilkan Cd dan Cl yang cenderung lebih tinggi dibanding eksperimen, namun deviasinya relatif konsisten pada seluruh variasi kecepatan, sehingga model CFD dapat digunakan untuk analisis kecenderungan aerodinamika bus.

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