Karakteristik Perpindahan Panas Konveksi Alamiah Aliran Nanofluida Al2o3-Air Di Dalam Pipa Anulus Vertikal

Abstract

ABSTRAKKARAKTERISTIK PERPINDAHAN PANAS KONVEKSI ALAMIAH ALIRAN NANOFLUIDA AL 2 O 3 -AIR DI DALAM PIPA ANULUS VERTIKAL. Hasil beberapa penelitian menunjukkan bahwa nanofluida memiliki karakteristik termal yang lebih baik dibandingkan dengan fluida konvensional (air). Berkaitan dengan hal tersebut, saat ini sedang berkembang pemikiran untuk menggunakan nanofluida sebagai fluida perpindahan panas alternatif pada sistem pendingin reaktor. Sementara itu, konveksi alamiah di dalam pipa anulus vertikal merupakan salah satu mekanisme perpindahan panas yang penting dan banyak ditemukan pada reaktor riset TRIGA, reaktor daya generasi baru dan alat konversi energi lainnya. Namun di sisi lain karakteristik perpindahan panas nanofluida di dalam pipa anulus vertikal belum banyak diketahui. Oleh karena itu penting dilakukan secara berkesinambungan penelitian-penelitian untuk menganalisis perpindahan panas nanofluida di dalam pipa anulus vertikal. Pada penelitian ini telah dilakukan analisis numerik menggunakan program computer CFD (computational of fluids dynamic) terhadap karakteristik perpindahan panas konveksi alamiah aliran nanofluida Al 2 O 3 -air konsentrasi 2% volume di dalam pipa anulus vertikal. Hasil kajian ini menunjukkan terjadi peningkatan kinerja perpindahan panas (bilangan Nuselt-N U ) sebesar 20,5% -35%. Pada moda konveksi alamiah dengan bilangan 2,471e +09 ≤ R a ≤ 1,955e ABSTRACT THE CHARACTERISTICS OF NATURAL CONVECTION HEAT TRANSFER OF AL 2 O 3 -WATER NANOFLUID FLOW IN A VERTICAL ANNULUS PIPE. Results of several researches have shown that nanofluids have better thermal characteristics than conventional fluid (water). In this regard, ideas for using nanofluids as an alternative heat transfer fluid in the reactor coolant system have been well developed. Meanwhile the natural convection in a vertical annulus pipe is one of the important mechanisms of heat transfer and is found at the TRIGA research reactor, the new generation nuclear power plants and other energy conversion devices. On the other hand, the heat transfer characteristics of nanofluids in a vertical

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