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The Visualization Study on the Slug Flow Mechanisms of the Air-Water Two-Phase in a 50 mm Horizontal Pipe Dinaryanto, Okto; Hudaya, Akhmad Zidni; Deendarlianto, Deendarlianto; Indarto, Indarto
SENATIK STT Adisutjipto Vol 4 (2018): Transformasi Teknologi untuk Mendukung Ketahanan Nasional [ ISBN 978-602-52742-0-6 ]
Publisher : Sekolah Tinggi Teknologi Adisutjipto

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (560.273 KB) | DOI: 10.28989/senatik.v4i0.171

Abstract

The slug flow phenomena are often encountered in various industrial applications such as petroleum, process, and power plant. The presence of slug flow should be avoided as it causes structural damage due to resonance, corrosion and pipes blast. From the view point of multiphase flow, the understanding of the slug initiation mechanism is very important in pipeline design. This research is conducted using horizontal transparent acrylic pipes with diameters of 50 mm with a variation on the superficial velocity of water between 0,1 m/s and 0,77 m/s and superficial velocity of air between 0,31 m/s and 6,2 m/s. In the present experimental study, the slug initiation mechanisms was explained by visual observation by using high speed video cameras. As the results, the slug flow initiation mechanism were clarified. Furthermore, the proposed of flow initiation map was introduced.
PEMISAHAN ALIRAN KEROSEN-AIR (Pada Variasi Sudut Kemiringan Side Arm vertikal keatas) Puspitasari, Dewi; Indarto, Indarto; Purnomo, Purnomo; Khasani, Khasani
ROTASI VOLUME 14, NOMOR 2, APRIL 2012
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1340.945 KB) | DOI: 10.14710/rotasi.14.2.11-16

Abstract

Penelitian mengenai pemisahan fase air-kerosen yang melewati T-junction telah dilakukan. Hasil pemisahan fase akan diamati dengan mengubah sudut kemiringan side arm (branch) dimulai dari posisi vertical keatas 90o, ,60o dan 30o dengan radius belokan 15 mm.Untuk mengamati pengaruh sudut kemiringan side arm terhadap pemisahan fase yang dihasilkan maka dibuatlah seksi uji T-junction dengan diameter pipa horisontal 36 mm, diameter side arm 26 mm (rasio diameter 0,7), bahan pipa adalah acrylic dengan variasi water cut 49% - 70%, kecepatan superfisial air 0,20 ~ 0,39 m/s, kecepatan superfisial kerosene 0,15 ~ 0,25 m/s pada tiga variasi hambatan downstream. Berdasarkan data hasil eksperimen dan visualisasi aliran pada seksi uji, hasil pemisahan fase terbaik dicapai pada sudut kemiringan branch 90o dengan tekanan downstream 107843,5 Pa, watercut 49% yang menghasilkan fraksi kerosene di branch Fk = 94,7% dan fraksi air di branch Fw = 3,4% dengan efisiensi pemisahan fase sebesar η = 95%. Kondisi terbaik diatas diperoleh pada Jw = 0,20 m/s, Jk = 0,22 m/s pada pola aliran Three Layer (3L-2).
Study on The Physical Characteristics and Hydrology of 15 Watershed in East Java Indarto, Indarto
Forum Geografi Vol 27, No 2 (2013): December 2013
Publisher : Universitas Muhammadiyah Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23917/forgeo.v27i2.2374

Abstract

The study demonstrated the application of statistical method to describe physical and hydro-meteorological characteristics by means of time series analysis.  Fifteen(15) watersheds in East Java were selected for this study. Data input for the analysis include: physical data, rainfall and discharge. Physical data of the watershed (topography, river network, land use, and soil type) are extracted from existing database and treated using GIS Software. Daily rainfall data were collected from existing pluviometers around the region. Daily discharge data were obtained from measurement station located at the outlet of each watershed. Areal Rainfall for each watershed was determined using average value of existing pluviometers around the watershed and determined using simple arithmetic method. These time series data are then imported to RAP (River Analysis Package).  Analysis on the RAP, include: general statistical, flow duration curve (FDC), and baseflow analysis. The result then presented in graphic and tables. Research shows that among the watersheds have different physical and hydrological characteristics.
FLUKTUASI BEDA TEKANAN DARI POLA ALIRAN SLUG AIR-UDARA PADA ALIRAN DUA FASE SEARAH PIPA HORIZONTAL Santoso, Budi; Indarto, Indarto; Deendarlianto, Deendarlianto; W., Thomas S.
ROTASI VOLUME 14, NOMOR 2, APRIL 2012
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (659.869 KB) | DOI: 10.14710/rotasi.14.2.1-6

Abstract

Karakteristik fluktuasi beda tekanan aliran slug dua fase udara-air diselidiki dalam pipa horisontal dengan panjang 10 m dan diameter dalam 24 mm. Tujuan penelitian ini adalah mengidentifikasi karakteristik dari fluktuasi beda tekanan pola aliran slug menggunakan analisis statistik, probability density function (pdf), autokorelasi dan power spectral density (psd). Sebuah sensor Differential Pressure Tansducer (DPT) dipasang untuk merekam fluktuasi beda tekanan aliran slug. Sinyal beda tekanan dikondisikan oleh pressure amplifier/signal conditioning dan diubah menjadi sinyal digital menggunakan peralatan Analog to Digital Converter (ADC). Karakteristik dari fluktuasi beda tekanan aliran slug sangat dipengaruhi oleh kecepatan superfisial fluida. Perubahan kecepatan superfisial udara dan kecepatan superfisial air dapat dibedakan dengan jelas menggunakan analisis statistik, PDF, autokorelasi dan PSD.
Karakterisasi Aliran Uap-Kondensat pada Saluran Mendatar Berdasarkan Pengukuran Temperatur Sukamta, Sukamta; Indarto, Indarto; Purnomo, Purnomo; Rokhmat, Tri Agung
Jurnal Semesta Teknika Vol 17, No 1 (2014): MEI 2014
Publisher : Jurnal Semesta Teknika

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Abstract

The objective of the current investigation is to find out temperature distribution regimes in a horizontal pipe when condensation process is happened.  The research was conducted at Pusat Studi Ilmu Teknik Universitas Gadjah Mada. The experiment apparatus consists of an inner annulus pipe made from copper (din = 17.2 mm, do = 19 mm) with the length of 1.8 m. The outer annulus pipe is a galvanized iron pipe (din = 108.3 mm, do = 114.3 mm) with the length of 1.6 m. Thermocouples type K 36 TT OMEGA with chromel (+) and alumel (-) materials were used as temperature sensors, to detect the spread of temperature in radial or axial direction along the pipe. The measurement ranged from -50 to 260 oC, with an accuracy of 0.01 °C. A data logger of RX 40 serial (OMRON, 20 Channels) was used to read and record temperature data with the sampling rate of 5 Hz. In the experiment, the water (H2O)was heated using a boiler to generate steam which was then flowed and condensed inside the annulus pipe to form a steam-condensate two-phase flow in horizontal pipe. On the other hand, the water was used as a coolant in the outer of annulus pipe. The results indicated that the temperature distribution regimes are influenced by axial posisition.The farther distances from the inlet the lower the temperatures being recorded which indicate the increase of film condensate thickness. Such phenomena can affect slugging in the location.
Identifikasi Pola Aliran Dua Fasa Uap-Kondensat Berdasarkan Pengukuran Beda Tekanan pada Pipa Horisontal Sukamta, Sukamta; Indarto, Indarto; Purnomo, Purnomo; Rohmat, Tri Agung
Jurnal Semesta Teknika Vol 13, No 1 (2010): MEI 2010
Publisher : Jurnal Semesta Teknika

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Abstract

An experiment of two-phase flow patterns of steam-condensate based on differential pressure measurement in horizontal tube was conducted by varying the flow rate of the steam. The experiment utilised annulus pipe with inner section test pipe was made from copper and outer section was made from Galvanized Iron Pipe (GIP) wrapped with a 10-mm-thick insulation. The pipe was 1.6 meter length, and 4 inch outer diameter and 17 mm inner diameter. The two-phase flow regime was investigated based on pressure gradien between its inlet and outlet. In order to support the result, visualition was conducted using a ¾ inch diameter and 1.3 m length of transparent pipe connected with the test pipe section. Five variations of steam flow rate ranging from 0.00211361 m3/s to 0.007078511 m3/s were selected. The results show that for lowest steam flow rate, stratified flow pattern was identified while for the ot her variations, stratified, wavy, plug and slug flow pattern were observed. Wavy flow pattern occured on transition of stratified to slug or plug. Annular flow pattern was not observed in this experiment. Generally speaking, an increase in steam flow rate resulted in a more significant pressure gradient signals.
Study on The Physical Characteristics and Hydrology of 15 Watershed in East Java Indarto, Indarto
Forum Geografi Vol 27, No 2 (2013): December 2013
Publisher : Universitas Muhammadiyah Surakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

The study demonstrated the application of statistical method to describe physical and hydro-meteorological characteristics by means of time series analysis.  Fifteen(15) watersheds in East Java were selected for this study. Data input for the analysis include: physical data, rainfall and discharge. Physical data of the watershed (topography, river network, land use, and soil type) are extracted from existing database and treated using GIS Software. Daily rainfall data were collected from existing pluviometers around the region. Daily discharge data were obtained from measurement station located at the outlet of each watershed. Areal Rainfall for each watershed was determined using average value of existing pluviometers around the watershed and determined using simple arithmetic method. These time series data are then imported to RAP (River Analysis Package).  Analysis on the RAP, include: general statistical, flow duration curve (FDC), and baseflow analysis. The result then presented in graphic and tables. Research shows that among the watersheds have different physical and hydrological characteristics.
Prosedur Kalibrasi dan Validasi Model SMAR untuk Mendeskripsikan Proses Hujan Aliran di Sub-DAS Rawatamtu Indarto, Indarto
Jurnal Teknik Sipil Vol 19, No 3 (2012)
Publisher : Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (675.943 KB)

Abstract

Abstrak. Model SMAR (Soil Moisture Accounting Rainfall Model) merupakan salah satu model hidrologi pada RRL (Rainfall Runoff Library) yang dapat digunakan untuk menghitung aliran permukaan (Run Off) dari suatu DAS. Data masukan utama untuk model adalah data hujan dan evapotranspirasi. Artikel ini membahas prosedur kalibrasi dan validasi model untuk mendeskripsikan proses hujan - aliran pada skala harian. Artikel juga memaparkan tentang manfaat user-interface dan visualisasi yang ada pada software (model) tersebut. Model dikalibrasi menggunakan data debit yang diperoleh dari sub-DAS Rawatamtu (Jawa Timur). Kombinasi dua metode (generic dan manual) digunakan selama proses kalibrasi dan validasi. Kalibrasi dilakukan pada separuh periode rekaman yang tersedia, sedangkan validasi dilakukan pada separuh periode yang ke dua. Hasil kalibrasi dan validasi dievaluasi menggunakan kriteria: Koefisien Nash-Sutcliffe, Koefisien korelasi (correlation coefficient) danperbedaan Run Off (difference in Run Off). Kalibrasi dan validasi menggunakan metode generic maupun manual menunjukkan bahwa model mampu mereproduksi proses utama dari Hujan menjadi Aliran (debit terhitung) pada sub-DAS tersebut. Hasil juga menunjukkan bahwa performance model kurang optimal pada periode validasi, hal ini dikarenakan keterbatasan data yang digunakan. Data yang lebih lengkap diperlukan untuk mengevaluasi performance model.Abstract. The Soil Moisture Accounting Rainfall Model (SMAR) is one of Rainfall Runoff Library Models (RRL) used to calculate Run-Off from rainfall and evapotranspiration data. This article shows the procedure to calibrate the model. Furthermore, this article also show the benefit of software fitur and user interface. Model is calibrated and validated using discharge data otained from Rawatamtu sub-Watershed (East Java). Two methodes (generic and manual) were exploited for the calibration and validation procceses. The result was evaluated by using the criteria of: Nash-Sutcliffe Coefficient, Coefficient of Correlation and difference in run-off. Calibration is conducted at the first half of recording periods, while validation is conducted at the second half of recording periods. The result shows that both generic and manual method can describe Rainfall to Run-Off process of the watershed, during calibration periode. However, during validation period model performance is not satisfied, due to the limit of data used. More data is needed to evaluate the model performance.
Variabilitas Spasial Hujan Harian di Jawa Timur Indarto, Indarto
Jurnal Teknik Sipil Vol 20, No 2 (2013)
Publisher : Institut Teknologi Bandung

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Abstract

Abstrak. Dua variabel digunakan untuk memaparkan variabilitas spasial hujan harian di Jawa Timur, yaitu: (1) Hujan-24jam-maksimal dan (2) Hari-Hujan. Data hujan diperoleh dari 946 lokasi stasiun hujan yang tersebar merata di seluruh wilayah Provinsi. Analisis spasial dilakukan menggunakan ESDA (Exploratory Spatial Data Analysis) yang ada pada ArcGIS Geostatistical Analyst. Tool yang digunakan mencakup: Histogram dan QQ-Plot. Selanjutnya, peta distribusi spasial (hujan-24jam-maksimal dan hari-hujan) di seluruh wilayah Jawa Timur dibuat dengan menggunakan metode Interpolasi Inverse Distance Weigthing (IDW). Hasil analisa menunjukkan Histogram dan Normal QQ-Plot untuk hari-hujan mendekati distribusi normal, sedangkan untuk hujan-24jam-maksimal lebih condong ke kanan. Statistik nilai hujan-24jam-maksimal yang diperoleh adalah: minimal = 32 mm, rerata = 137 mm, maximum = 332 mm, and median = 130 mm/hari. Nilai ringkasan distribusi statistik lainnya adalah:  standar deviasai = 50,37; koefisien kemencengan = 0,99; dan koefisien kurtosis = 4,3. Statistik untuk variabel hari-hujan, menunjukkan nilai minimal = 4 hari/tahun dan maksimal = 184 hari/tahun. Sedangkan, nilai rerata = 81 hari/tahun dan nilai median = 80 hari/tahun. Histogram juga menampilkan nilai standar deviasi = 23,74; koefisien skewness = 0,28; dan koefisien curtosis = (3,6). Penelitian menunjukkan kemampuan dan manfaat ESDA untuk menggambarkan variabilitas spasial hujan harian dengan lebih detail.Abstract. Two variabel (maximum-24hour-rainfall and number of rainfall-day) were used to describe the spatial variabiity of Daily Rainfall phenomena in East Java regions. Daily rainfall data were collected from 946 pluviometres spread around the regions. Spatial analyst were exploited by means of Exploratory Spatial Data Analysis (ESDA) available at ArcGIS Geostatistical Analyst. Histogram and QQ-Plot were used for the analysist. Furthermore, thematic map visualized the spatial variability of daily rainfall data over the region was produced using Inverse Distance Weighting (IDW) interpolation method. Results shows that both Histogram and Normal QQ-Plot for number-ofrainffal-day are close to normal distribution, however spatial distribution of 24-hour rainfall data is quitely distorsed to standard normal distribution. Statistical resume obtained from 24hour-rainfall data are : minimum = 32 mm/day, average = 137 mm/day, maximum = 332 mm/day, median = 130 mm/day, standard deviation = 50,37, coefficient of skewness = 0,99, and Coefficient of Curtosis = 4,3. Other statistical value resumed from number of rainy-day are : minimum = 4 day/year, average = 81 day/year, maximum = 184 day/year, and median = 80 day/year, standard deviation = 23,74, coefficient of skewness = 0,28, and Coefficient of curtosis = 3,6. The research demonstrate the capability and benefit of those statistical tool to describe spatial variability of daily rainffal phenomenon in East Java Regions.
KARAKTERISTIK PENDIDIHAN DALAM CELAH SEMPIT REKTANGULAR VERTIKAL DENGAN VARIASI TEMPERATUR AWAL PLAT Catrawedarma, I Gusti Ngurah Bagus; Indarto, Indarto; Juarsa, Mulya
Media Mesin: Majalah Teknik Mesin Vol 18, No 1 (2017)
Publisher : Universitas Muhammadiyah Surakarta

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Abstract

Analisis perpindahan kalor pendidihan untuk mengetahui pengaruh temperatur awal plat utama terhadap karakteristik pendidihan yang meliputi waktu rewetting, pola rewetting, fluks kalor, serta Critical Heat Flux (CHF) telah dipelajari berdasarkan kurva pendidihan dan fluks kalor yang dihitung dari transien temperatur permukaan plat, yang merupakan hasil eksperimen dengan menggunakan 2 plat vertikal dengan celah sempit antar plat utama dan penutup adalah 1 mm. Debit dan temperatur air pendingin ditetapkan sebesar 0,09 lt/detik dan temperatur saturasi. Temperatur awal plat utama divariasikan dari 500oC, 550oC, dan 600oC. Hasil analisis menunjukkan bahwa waktu rewetting terendah sebesar 30 sekon dan tertinggi sebesar 290 sekon. CHF tertinggi sebesar 750 kW/m2 dan terendah sebesar 400 kW/m2. Semakin tinggi temperatur awal plat, maka semakin lama waktu rewettingnya. Perubahan temperatur awal plat utama tidak mempengaruhi pola rewetting. Semakin tinggi temperatur awal plat, maka nilai CHF-nya semakin rendah. Daerah didih film tidak sesuai dengan kasus pool boiling. Pada daerah transisi, semakin rendah temperatur awal plat, maka semakin mendekati korelasi Murase. Nilai CHF mendekati korelasi Leinhard. Titik Leidenfrost sesuai dengan korelasi Zuber. Daerah didih inti mendekati korelasi Murase untuk superheat vapor.