RANCANG BANGUN DAN ANALISIS KINERJA PROPULSI ROKET PADAT BERBAHAN KNO₃-SUKROSA DENGAN VARIASI RASIO KOMPOSISI

Penelitian ini bertujuan untuk merancang dan menganalisis kinerja propulsi roket padat berbahan potassium nitrat (KNO₃) dan sukrosa dengan variasi rasio komposisi 70%:30% dan 60%:40%. Variasi komposisi dilakukan untuk mengetahui pengaruh perbandingan oksidator dan bahan bakar terhadap gaya dorong (thrust), karakteristik pembakaran, dan kestabilan performa propulsi. Penelitian menggunakan metode eksperimen kuantitatif dengan pembuatan propelan melalui Heat/Melt-Cast Method. Propelan ditempatkan pada combustion chamber berbahan stainless steel dan diuji secara statis menggunakan timbangan digital sebagai alat ukur gaya dorong. Masing-masing komposisi diuji sebanyak dua kali, kemudian dianalisis berdasarkan nilai rata-rata hasil pengujian.
Hasil penelitian menunjukkan bahwa komposisi 70% KNO₃ dan 30% sukrosa menghasilkan performa propulsi yang lebih baik dibandingkan komposisi 60% KNO₃ dan 40% sukrosa. Komposisi 70%:30% menghasilkan gaya dorong maksimum rata-rata sebesar 49,91 N, sedangkan komposisi 60%:40% menghasilkan gaya dorong maksimum rata-rata sebesar 34,97 N. Selain menghasilkan gaya dorong yang lebih tinggi, komposisi 70%:30% menunjukkan proses pembakaran yang lebih stabil dengan residu pembakaran yang lebih sedikit. Hal ini menunjukkan bahwa peningkatan fraksi oksidator meningkatkan efisiensi pembakaran sehingga energi yang dihasilkan lebih optimal.
Berdasarkan hasil penelitian dapat disimpulkan bahwa variasi rasio komposisi propelan berpengaruh signifikan terhadap performa propulsi roket padat. Komposisi 70% KNO₃ dan 30% sukrosa merupakan komposisi yang memberikan kinerja terbaik pada rancangan motor roket yang digunakan dalam penelitian ini.

Kata kunci: propulsi roket padat, potassium nitrat, sukrosa, gaya dorong, KNO₃, Heat/Melt-Cast Method.

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This study aims to design and analyze the performance of a solid rocket propulsion system using potassium nitrate (KNO₃) and glucose propellant with composition ratios of 70:30 and 60:40. The variation in propellant composition was conducted to determine the effect of oxidizer-to-fuel ratio on thrust, combustion characteristics, and propulsion performance stability. An experimental quantitative method was employed, in which the propellant was fabricated using the Heat/Melt-Cast Method. The propellant was placed inside a stainless-steel combustion chamber and tested through a static firing test using a digital scale to measure the generated thrust. Each propellant composition was tested twice, and the average values were used for data analysis.
The results indicate that the propellant composition containing 70% potassium nitrate and 30% glucose produced superior propulsion performance compared to the 60% potassium nitrate and 40% glucose composition. The 70:30 composition generated an average maximum thrust of 49.91 N, while the 60:40 composition produced an average maximum thrust of 34.97 N. In addition to generating higher thrust, the 70:30 composition exhibited a more stable combustion process and produced less combustion residue. These findings suggest that increasing the oxidizer fraction improves combustion efficiency, resulting in greater energy release and enhanced propulsion performance.
It can be concluded that the propellant composition ratio significantly affects the performance of solid rocket propulsion. Among the tested formulations, the 70% potassium nitrate and 30% glucose composition demonstrated the best overall performance for the rocket motor developed in this study.

Keywords: solid rocket propulsion, potassium nitrate, glucose, thrust, KNO₃, Heat/Melt-Cast Method.