Studi Eksperimental Aliran Dua Fasa Fluida Non-Newtonian Carboxymethyl Cellulose (CMC) Konsentrasi 0,2% dan Nitrogen pada Microchannel Penampang Persegi dengan Perubahan Luas Penampang

MUHAMMAD ASHIF N U, Prof. Dr. Eng. Ir. Deendarlianto, S.T., M.Eng.

2022 | Skripsi | S1 TEKNIK MESIN

Studi eksperimental terhadap aliran dua fasa fluida non-newtonian dilakukan pada sebuah microchannel penampang persegi dengan fitur perubahan luas penampang. Aliran dua fasa non-newtonian berupa Carboxymethyl cellulose (CMC) - 0,2% - Nitrogen, dialirkan pada microchannel dengan DH= 0,8 mm pada bagian upstream dan DH= 0,5 mm pada bagian downstream. Variasi kecepatan superfisial gas (JG) memiliki rentang JG= 0,26 - 7,81 m/s dan kecepatan superfisial likuid memiliki rentang JL=0,05 - 1 m/s Aliran dua fasa newtonian berupa akuades - Nitrogen digunakan sebagai pembanding. Fenomena pressure drop, pola aliran, dan karakteristik slug diamati pada penelitian ini. Beberapa pola aliran yang terbentuk antara lain slug flow, elongated slug - flow, slug - annular flow, dan churn flow. Dari pola aliran yang terbentuk, dibuat peta pola aliran dan dibandingkan dengan penelitian terdahulu.. Untuk segi karakteristik slug, perubahan luas penampang mengakibatkan meningkatnya panjang dan kecepatan slug dari bagian upstream ke downstream microchannel. Karakteristik slug berupa panjang slug lebih tinggi pada fluida newtonian akuades. Kecepatan slug lebih tinggi pada fluida non-newtonian CMC 0,2%. Karakteristik slug tersebut dipengaruhi oleh perbedan viskositas pada kedua fluida uji. Di sisi lain, perubahan luas penampang menyebabkan pressure drop yang terjadi pada downstream microchannel meningkat lebih signifikan. Selain itu, meningkatnya nilai kecepatan superfisial likuid (JL) diikuti dengan meningkatnya pressure drop. Fluida non-newtonian CMC 0,2% memiliki pressure drop yang lebih tinggi dibanding fluida newtonian akuades.

Experimental studies on the two-phase flow of non-Newtonian fluids were carried out on a rectangular cross-sectional microchannel with the feature of cross-sectional area changes. Two-phase non-Newtonian flow in the form of Carboxymethyl cellulose (CMC) 0.2% concentration - Nitrogen, flowed in a microchannel with DH= 0.8 mm in the upstream and DH = 0.5 mm in the downstream. Variations in superficial gas velocity (JG) has a range of JG= 0.26 -7.81 m/s and the superficial liquid velocity has a range of JL= 0.05 - 1 m/s. Two-phase Newtonian flow in the form of aquadest - Nitrogen is used as a comparison. The phenomena of pressure drop, flow pattern, and slug characteristics were observed in this study. Some of the flow patterns formed include slug flow, elongated-slug flow, slug-annular flow, and churn flow. Based on the flow pattern formed, a flow pattern map is made and compared with previous research. In terms of slug characteristics, changes in cross-sectional area result in an increase in the slug length and slug velocity from the upstream to the downstream microchannel. Slug characteristics in the form of higher slug length is found on Newtonian aquadest fluid. The slug velocity is higher in the non-Newtonian CMC 0.2% fluid. The characteristics of the slug are influenced by the difference in viscosity of the two test fluids. On the other hand, the change in cross-sectional area causes the pressure drop that occurs in the downstream microchannel to increase significantly. In addition, the increase in the value of the liquid superficial velocity (JL) is followed by an increase in the pressure drop. Non-Newtonian CMC 0.2% fluid has a higher pressure drop than aquadest Newtonian fluid.

Kata Kunci : Aliran Dua Fasa, Microchannel, Non-Newtonian, Perubahan Luas, Kontraksi, Pola Aliran, Karakteristik Slug, Penurunan Tekanan,Two-Phase Flow, Microchannel, Non-Newtonian, Change of Area, Contraction, Flow Pattern, Slug Characteristics, Pressure Drop