STUDI EKSPERIMENTAL KARAKTERISTIK ALIRAN DUA FASA FLUIDA NON-NEWTONIAN CARBOXYMETHYL CELLULOSE (CMC) KONSENTRASI 0,2% DAN NITROGEN PADA PENAMPANG PERSEGI SALURAN MICROCHANNEL

M.RIAN ALIF MADANI, Prof. Dr. Eng. Deendarlianto, S.T., M.Eng.

2022 | Skripsi | S1 TEKNIK MESIN

Studi eksperimental aliran dua fasa pada saluran microchannel dilakukan terhadap karakteristik pola aliran untuk fluida newtonian dan perbandingannya secara spesifik dengan fluida non-newtonian untuk karakteristik pola aliran yang terbentuk. Setelah itu, dilakukan pengamatan pada karakteristik pola aliran yang terbentuk pada fluida non-newtonian yang sama namun dibedakan konsentrasinya hingga mempunyai variasi properties reologi signifikan. Saluran microchannel berpenampang persegi dengan ukuran 0,8 mm x 0,8 mm dilewati oleh fluida kerja cairan newtonian berupa Air dan non-newtonian berupa Carboxymethyl Cellulose (CMC) konsentrasi 0,2% serta 0,4% dengan nitrogen sebagai fluida kerja gas. Kecepatan superfisial cairan yang digunakan adalah pada rentang JL= 0,05 � 1 m/s dan gas JG = 0,07 � 8,594 m/s. Karakteristik pola aliran yang terbentuk dianalisis menggunakan high speed camera serta mendapatkan pola aliran bubbly, slug, slug-churn, churn, wavy-annular, dan slug-annular. Peta pola aliran yang dihasilkan memiliki kesesuaian yang cukup baik terhadap penelitian terdahulu. Karakteristik slug seperti frekuensi kemunculan, panjang, dan kecepatan dianalisa dengan membandingkan fluida kerja Air dan CMC (0,2% dan 0,4%) serta pengaruh variasi JG dan JL menggunakan metode image processing dengan aplikasi MATLAB R2021a. Pola aliran yang teridentifikasi adalah bubbly, slug, slug-churn, churn, wavy-annular, dan slug-annular. Karakteristik slug seperti geometri dan waktu pembentukan dianalisa dengan membandingkan fluida kerja Air, CMC 0,2%, dan CMC 0,4% serta pengaruh variasi JG dan JL. JL memiliki pengaruh yang lebih signifikan dibandingkan JG pada gradien penurunan tekanan. Konstanta korelasi (C) akan memberikan persentase eror berbeda dalam memprediksi gradien penurunan tekanan aliran dua fasa sesuai dengan parameter yang mempengaruhinya.

Experimental studies of two-phase flow in microchannels were carried out on the characteristics of the flow pattern for Newtonian Fluids and their specific comparison with non-Newtonian Fluids for the characteristics of the formed flow patterns. After that, observations were made on the characteristics of the flow pattern formed in the same non-Newtonian fluid but differing in concentration so that it had significant variations in rheological properties. The microchannel with a square cross section with a size of 0.8 mm x 0.8 mm is passed by the Newtonian fluid working fluid in the form of water and non-Newtonian in the form of Carboxymethyl Cellulose (CMC) with 0.2% concentration and 0.4% with nitrogen as the gas working fluid. The superficial velocity of the liquid used is in the range of JL= 0.05 � 1 m/s and gas JG = 0.07 8.594 m/s. The characteristics of the flow pattern formed were analyzed using a high-speed camera and obtained the flow patterns of bubbly, slug, slug-churn, churn, wavy-annular, and slug-annular. The resulting flow pattern map has a good match with previous research. Slug characteristics such as frequency of occurrence, length, and speed were analyzed by comparing the working fluids of water and CMC (0.2% and 0.4%) and the effect of JG and JL variations using the image processing method with MATLAB R2021a. The identified flow patterns are bubbly, slug, slug-churn, churn, wavy-annular, and slug-annular. Slug characteristics such as geometry and formation time were analyzed by comparing the working fluids of Water, CMC 0.2%, and CMC 0.4% and the effect of JG and JL variations. JL has a more significant effect than JG on the pressure drop gradient. The correlation constant (C) will give a different percentage of error in predicting the pressure drop gradient of the two-phase flow according to the parameters that affect it.

Kata Kunci : Two-Phase Flow, Microchannel, Flow Pattern, Newtonian Fluid, Non-Newtonian Fluid, Rheological Properties, Viscosity.