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All Journal JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI Makara Journal of Technology JURNAL REKAYASA KIMIA & LINGKUNGAN
Cindy Dianita, Cindy
Universitas Indonesia
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Civil Engineering, Building, Construction & Architecture Computer Science & IT Electrical & Electronics Engineering Energy Engineering Industrial & Manufacturing Engineering Materials Science & Nanotechnology Mechanical Engineering Public Health

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A Comparison of American, Norwegian, and Russian Standards in Calculating the Wall Thickness of Submarine Gas Pipeline Dianita, Cindy; Dmitrieva, Tatyana Vladimirovna
Makara Journal of Technology Vol. 20, No. 1
Publisher : UI Scholars Hub

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

Abstract

One of the key issues in the pipeline design is wall thickness calculation. This paper highlights a comparison of wall thickness calculation methods of submarine gas pipeline based on Norwegian Standard (DNV-OS-F101), Indonesian Standard SNI 3474 which refers to American Standard (ASME B31.8), and Russian Standard (VN39-1.9-005-98). A calculation of wall thickness for a submarine gas pipeline in Indonesia (pressure 12 MPa, external diameter 668 mm) gives the results of 18.2 mm (VN39-1.9-005-98), 16 mm (ASME B31.8), and 13.5 mm (DNV-OS-F101).The design formula of hoop stress due to internal pressure is interpreted in different ways for every standard. Only Norwegian Standard requires calculating hoop stresses in the inner surface, which leads to a decreased value of the wall thickness. Furthermore, the calculation of collapse factor due to external pressure is only regulated in American and Norwegian Standards while Russian Standard uses that factor as an intermediate parameter in calculating local buckling. For propagation buckling, either Russian or American Standard explains empirical formula of critical hydrostatics pressure as the input in propagation buckling calculation. This formula is almost similar to the empirical formula of Norwegian Standard. From the comparison of these standards, DNV OS-F101 gives more stringent requirements than others.
CFD Simulation and Statistical Analysis of Experimental Designs for Blood Flow in T-Junction Vessels Dianita, Cindy; Nastasya, Catherine
JURNAL Al-AZHAR INDONESIA SERI SAINS DAN TEKNOLOGI Vol 10, No 1 (2025): January 2025
Publisher : Universitas Al Azhar Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.36722/sst.v10i1.2874

Abstract

The blood vessel area that has the greatest chance of atherosclerotic plaque deposition is the bifurcation zone (branching) in the carotid artery. The non-Newtonian fluid of blood has the characteristics of a shear-thinning fluid. Computational Fluid Dynamics (CFD) simulation is used in this study to analyse hemodynamic in carotid artery flow with variations of vessel geometry. The branching geometry of the arteries is represented by a T-junction model which is the ideal simplified blood vessel geometry model to exhibit the most common behaviour in arterial bifurcations. The geometry of the T branch is varied into 4 different combinations of diameter size. Thus, the 2k factorial experimental design method is also used to investigate the effect of the inflow and outflow domain sizes on the response variables in the form of velocity values, Wall Shear Stress (WSS), and Oscillatory Shear Index (OSI). The results of this simulation can greatly help medical scientists to more easily predict areas that have the potential to form atherosclerotic plaques in the circulatory system.Keywords - Atherosclerotic Plaque, Blood Vessel, Computational Fluid Dynamics Non-Newtonian Fluid, 2k Factorial Method.
The Effect of Heat Tracing Installation for Wax Prevention on Onshore Buried Swampy Pipelines Santoso, Samuel Bagas Wahyu; Sommeng, Andy Noorsaman; Dianita, Cindy
Jurnal Rekayasa Kimia & Lingkungan Vol 19, No 1 (2024): Jurnal Rekayasa Kimia & Lingkungan (June 2024 )
Publisher : Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23955/rkl.v19i1.37754

Abstract

Transporting crude oil using pipelines is a widely adopted method globally. In one segment owned by PT. XYZ, especially in swampy areas, the fluid temperature tends to drop below the wax appearance temperature (WAT) during oil transportation. This is due to the relatively low temperature in swamp areas caused by heat loss to the environment. The solubility of paraffin in crude oil drastically decreases as fluid temperature drops, causing wax molecules to precipitate and deposit on the cold pipe walls. PT. XYZ employs chemical treatment by adding a pour point depressant (PPD) to lower the pour point temperature (PPT). However, PPD is effective only at certain temperatures, necessitating a study for alternative treatments. Another method involves installing heaters on the pipeline to reduce the viscosity of transported crude oil and enhance its flowability, either through direct heating or heat tracing using insulation with low thermal conductivity. Therefore, in PT. XYZ's case, an analysis is required to identify locations where fluid temperature decreases occur to ensure precise heater installation. Various software tools, including OLGA, have been developed to predict and describe wax deposition phenomena and temperature decreases along the pipeline. OLGA software can simulate locations of fluid temperature decreases in the pipeline, estimate heat loss along the pipeline, and simulate heat tracing technologies to prevent wax deposition. Simulation results indicate that wax deposition can be prevented by installing skin effect heat tracing with a heating power of 15 W/m and insulated with 2-inch aerogel, maintaining the oil temperature downstream at 157.34F, well above the desired 115F threshold.
Simulation of Drag Reducer Polymer (DRP) for Single and Annular Two Phase Flow in Horizontal Pipe Dianita, Cindy; Saputra, Asep Handaya; Khairunissa, Puteri Amelia
Jurnal Rekayasa Kimia & Lingkungan Vol 13, No 2 (2018): Jurnal Rekayasa Kimia & Lingkungan (December, 2018)
Publisher : Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23955/rkl.v13i2.11784

Abstract

Drag reducing polymers (DRP) is one of drag reducer types that is widely used in industry as an additive to improve fluid flow efficiency in pipes. This study is conducted to analyze the parameters that influence the efficiency of DRP through developing equation model, and to see the phenomenon of drag reduction that occurs in fluid flow through computational fluid dynamic (CFD) simulation. The data used are obtained from experiments by Vancko (1997) for a single phase flow of water. As for two-phase annular flow, four experiments data are used namely by Vancko (1997), Al-Sarkhi and Hanratty (2001a,b) and Fernandes et al. (2004). Parameters such as fluid velocity and pipe diameter are analyzed based on the model equations proposed in this study. The final single phase flow equation model as the output of this study gives a value for onset drag reduction i.e 4.00 with an error up to 18%. While the proposed annular flow equation with and without drag reduction effect is only suitable when the condition of fluid film distribution is uniform and symmetrical with the error around 20%, i.e. for smaller diameter pipes. The CFD simulation results shows a change in the fluid velocity profile; becoming more parabolic, indicating an increase in the mean fluid velocity up to 0.43%, as the effect of DRP.
Co-Authors Asep Handaya Saputra Khairunissa, Puteri Amelia Mardianza, Andi Nastasya, Catherine Santoso, Samuel Bagas Wahyu Sommeng, Andy Noorsaman Tatyana Vladimirovna Dmitrieva, Tatyana Vladimirovna