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Abstrak :
Koefisien perpindahan kalor dan penurunan tekanan didapat dari pengujian pada kanal mini horizontal berukuran diameter luar 5 mm, diameter dalam 3mm dan panjang 1 m dengan material stainless steel 316L. Nilai koefisien perpindahan kalor dihitung pada kisaran nilai fluks massa 50 hingga 250 kg m-2 s-1 , fluks panas 1 hingga 8 kW m-2, temperatur saturasi hingga 100C, kualitas uap hingga 1 dan menggunakan fluida kerja Propane dan Iso-butane. Kalor diaplikasikan pada kanal mini horizontal dengan menggunakan lilitan kawat nikel yang dihubungkan ke sumber daya yang dapat diatur daya nya. Hasil dari eksperimen ini dibandingkan dengan beberapa korelasi yang sudah ada sebelumnya dan dilihat perbandingannya. Korelasi koefisien perpindahan kalor dan penurunan tekanan dikembangkan dari data hasil ekperimen ini. ...... The coefficient of heat transfer and pressure drop obtained from an experiment on a horizontal mini channel with outer diameter of 5 mm, inner diameter of 3mm and a length of 1 m using 316L stainless steel material. Heat transfer coefficient calculated in the range of mass flux value from 50 to 250 kg m-2 s-1, a heat flux of up to 8 kW m-2, the saturation temperature up to 100C, quality up to 1 and use Propane and iso-butane as the working fluid. Heat was applied to the horizontal mini channel using nickel wire coil which is connected to a power source. The results of this experiment compared with some pre-existing correlations and see the comparison. The correlation coefficient of heat transfer and pressure drop were developed from the results of this experiment.

Abstrak :
Penelitian ini membahas tentang karakteristik perpindahan kalor aliran dua fasa yang didapat berdasarkan pengujian dan dibandingkan dengan prediksi korelasi yang terdapat pada literatur. Percobaan ini dilakukan dengan menggunakan refrijeran R-22 dan R-290 yang dilakukan dalam pipa konvesional berdiameter 7,6 mm dengan bahan stainless steel (SS 316) dan panjang 1,07 m. Pengujian dilakukan dengan variasi fluks kalor (q), fluks massa (G), dan temperatur saturasi. Hasil yang didapat pada penelitian ini adalah nilai fluks massa yang tinggi cenderung memiliki nilai koefisien perpindahan kalor yang tinggi pada awal evaporasi dan jika diberikan fluks kalor yang tinggi maka nilai koefisien perpindahan kalor juga akan naik, dan sistem dengan nilai temperatur saturasi yang tinggi maka akan dipengaruhi oleh koefisien perpindahan panas nucleat boiling. Perbandingan refrijeran mengindikasikan bahwa nilai koefisien perpindahan kalor R-290 lebih tinggi daripada R-22. ...... This study discusses about the characteristics of two-phase flow which obtained by experiment and the data is compared with predictions data of correlations in the literature. This experiment was conducted using refrijeran R-22 and R-290 in a conventional 7,6 mm pipe with stainless steel (SS 316) material and length of 1,07 m. Tests carried out with variations of heat flux (q), mass flux (G), and the saturation temperature. The result of this study is high value of the mass flux values tend to have a high coefficient of heat transfer at the beginning of evaporation and high heat flux will increase the heat transfer coefficient value. Systems with a high value of the saturation temperature will be influenced by nucleat boiling heat transfer coefficient. Refrijeran comparison indicates that the value of heat transfer coefficient of R-290 is higher than R-22.

Abstrak :
Research to nanofluida have a lot of conducted to indicate that nanofluida has a great potency for better heat transfer. Nanofluida is mixture between solid particle of nanosize with the based-fluid. Nano particle suspended in based-fluid permanently which is because of eristence of Brownian eject. Before nanofluida can be applied in commercial purpose, the furthermore experiment is needed. In this research conducted the measurement of heat transfer coefficient jilm condensation which used vertical condenser and nanofluids Al2O3-water as cooling fluids With variation of flow rote of cooling fluid and volume concentration of nanofluid as well, the experimental result shows the enhancement of condensation heat transfer coefficient with nanofluid compared to base fluids : 12- 19% for 1% particles concentration and 23-33 % for 4% particles concentration.