Hasil Pencarian  ::  Simpan CSV :: Kembali

Abstrak :
ABSTRAK
Microbubble merupakan gelembung udara dengan diameter kurang dari 200 m di dalam air. Karakteristik unik yang dimiliki microbubble menyebabkan maraknya penggunaan microbubble dalam dunia industri. Penelitian mengenai performa dari generator microbubble dengan tabung silinder telah dilakukan. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh debit air, debit udara masuk, void fraction, pressure drop, dan jumlah lubang udara terhadap performa dari microbubble generator. Penelitian dilakukan dengan menerapkan sistem water loop dan menggunakan dua tipe microbubble generator. Tipe-tipe microbubble generator tersebut adalah tipe dengan 12 lubang udara dan 48 lubang udara pada set up alat uji. Setelah dilakukan penelitian, ukuran bubble yang dihasilkan serta tipe microbubble generator yang tepat ditemukan. Tipe 2 48 lubang menghasilkan persentase microbubble yang lebih banyak. Hal ini terbukti paling optimum pada keadaan Qa= 30 lpm dan Qu=0,6 lpm.

---

ABSTRACT
Microbubbles are bubbles with the diameter size smaller than 200 m. The unique characteristics of microbubbles enhance its industrial utilization. The research about Microbubble Generator with a Spherical Body has been done. The objection of this research is to find the relevance between water flow rate, air flow rate, void fraction, pressure drop, and the number of air suction holes with the performance of microbubble generator. The research is done by applying water loop system and two types of microbubble generator. The types of microbubble generator are microbubble generator with 12 air suction holes and 48 air suction holes for the experimental set up. The results of this research are the size of bubbles which are generated and the recommended microbubble generator type. Microbubble generator with 48 air suction holes is the optimum generator of this research. The optimum condition is 30 lpm for the water flow value and 0,6 lpm for the air flow.

Abstrak :
An investigation into flow boiling void fraction was conducted to observe its characteristics and to develop a new correlation of void fraction based on the separated model. The study used a natural refrigerant of R-290, flowed in a horizontal tube of 7.6 mm inner diameter under experimental conditions of 3.7 to 9.6oC saturation temperature, 10 to 25 kW/m2 heat flux, and 185 to 445 kg/m2s mass flux. The void fraction, calculated by the present experimental data, was used for comparison with 31 existing correlations, including model types as follows: homogeneous, slip ratio, K?h correlation, drift flux, and a model based on the Lockhart-Martinelli correlation (Xtt). A new void fraction correlation, as a function of liquid and vapor Reynolds numbers, was proposed, based on the data. The measured pressure drop was compared with some pressure drop correlations that use the newly developed void fraction combination. The best prediction was shown by the homogeneous model.