Claim Missing Document
Check
Articles

Found 6 Documents
Search

PENGARUH TEKANAN BOILER DAN VARIASI PANJANG THROAT TERHADAP PERFORMA STEAM EJECTOR Fahris, Mohamad; Utomo, Tony Suryo; Syaiful, Syaiful
Simetris: Jurnal Teknik Mesin, Elektro dan Ilmu Komputer Vol 5, No 1 (2014): Jurnal Simetris
Publisher : Universitas Muria Kudus

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (324.472 KB) | DOI: 10.24176/simet.v5i1.137

Abstract

ABSTRAK Siklus steam ejector refrigeration memiliki kontrsuksi yang sederhana, sedikit bagian yang bergerak sehingga lebih ekonomis, dibanding dengan siklus kompresi uap lainya. Siklus ini juga sangat ramah lingkungan karena menggunakan air sebagai fluida refrigerant. Ejector merupakan bagian yang sangat berpengaruh pada siklus ini, kinerja ejector dapat dilihat dari besar kecilnya nilai entrainment rationya, yaitu perbandingan laju aliran masa dari boiler dengan laju aliran masa dari evaporator. Dalam siklus ini melakukan eksperimen dengan memvariasikan kondisi operasi tekanan boiler 5kg/cm2, 4kg/cm2, 3kg/cm2, dan modifikasi panjang throat steam ejector. Panjang throat yang digunakan yaitu 2D, 3D, 4D, dan 5D. 2D artinya 2 kali diameter throat, dimana diameter throat adalah 18 mm. Hasil eksperimen menunjukkan panjang throat optimal adalah 72 mm (4D) pada tekanan 5kg/cm2 dengan nilai entraiment ratio 0.17543 dan yang paling rendah adalah pada panjang throat 2D pada tekanan boiler 3kg/cm2. Kata kunci: steam ejector, entrainment ratio, throat.
ANALISA PENGARUH POSISI KELUARAN NOSEL PRIMER TERHADAP PERFORMA STEAM EJECTOR MENGGUNAKAN CFD Utomo, Tony Suryo; Nugroho, Sri; Yohana, Eflita
ROTASI VOLUME 13, NOMOR 2, APRIL 2011
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (463.725 KB) | DOI: 10.14710/rotasi.13.2.22-26

Abstract

Steam ejector refrigerasi merupakan sistem refrigerasi dengan memanfaatkan panas buangan sebagai inputnya. Steam ejector berperan sebagai pengganti kompresor pada siklus kompresi uap. Steam ejector refrigerasi memiliki COP (Coefficient of Performance) yang rendah, sehingga perlu dilakukan penelitian untuk mengoptimalkan kinerja dari steam ejector. Kinerja steam ejector dapat dilihat dari besarnya nilai entrainment ratio yaitu perbandingan laju aliran massa suction dengan laju aliran massa motive. Peningkatan nilai entrainment ratio pada steam ejector dapat meningkatkan COP dari sistem refrigerasi tersebut. Dalam penelitian ini, Computational Fluid Dynamics (CFD) digunakan untuk memprediksi fenomena aliran dan performansi steam ejector. Simulasi dilakukan dengan memodifikasi posisi keluaran nosel primer yaitu jarak nosel dengan constant-area section steam ejector. Jarak nosel dengan constant-area (throat) section steam ejector divariasikan dari 0.1 sampai 5 kali diameter constant-area section. Hasil simulasi menunjukkan performansi optimum diperoleh pada jarak nosel antara 1.5 sampai 4 kali diameter constant-area section. Semakin besar diameter throat nosel maka nilai entrainment ratio semakin menurun.
SIMULASI AERODINAMIKA PADA MODEL SIMPLIFIED BUS MENGGUNAKAN PROGRAM COMPUTATIONAL FLUID DYNAMICS Utomo, Tony Suryo
ROTASI Volume 8, Nomor 1, Januari 2006
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (606.129 KB) | DOI: 10.14710/rotasi.8.1.34-37

Abstract

Pada penelitian ini simulasi aerodinamika menggunakan program CFD (Computational Fluid Dynamics)dilakukan pada model kendaraan simplified bus berdasarkan eksperimen Duell dan George [1999] yang disimulasikanpula oleh Krajnovic dan Davidson [2001]. Pada simulasi ini, digunakan model turbulen k-ε standard dengan berbagaivariasi model diskretisasi pada Pressure, Pressure-Velocity coupling, Momentum, Turbulence Kinetic Energy, danTurbulence Dissipation rate. Tujuannya adalah untuk mencari metode diskretisasi yang terbaik pada kasus simulasiaerodinamika ini. Dalam hal ini, hasil simulasi dari berbagai variasi metode diskretisasi tersebut dibandingkan denganhasil ekseperimen [Duell & George, 1999] dan hasil simulasi menggunakan model LES [Krajnovic & Davidson, 2001].Dari hasil simulasi diperoleh data-data karakteristik aerodinamika berupa drag coefficient (CD) dan liftcoefficient (CL) yang sesuai dengan data eksperimen maupun hasil simulasi LES. Disamping itu visualisasi pola aliranudara disekeliling model simplified bus juga dilakukan untuk divalidasi terhadap hasil simulasi LES. Dari sinididapatkan kode-kode simulasi yang terbaik yaitu model turbulen standard k - e (standard wall function) denganmetode diskretisasi Standard Pressure, SIMPLE Pressure-Velocity coupling, 2nd order Upwind Scheme untukMomentum dan Turbulence Kinetic Energy, serta 1st order Upwind Scheme Turbulence Dissipation Rate.
SIMULASI EFEK TURBO CYCLONE TERHADAP KARAKTERISTIK ALIRAN UDARA PADA SALURAN UDARA SUATU MOTOR BAKAR MENGGUNAKAN COMPUTATIONAL FLUID DYNAMICS Utomo, Tony Suryo
ROTASI Volume 8, Nomor 2, April 2006
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (460.498 KB) | DOI: 10.14710/rotasi.8.2.30-36

Abstract

Turbo Cyclone is an additional device for an internal combustion engine, which can be used to create swirledflows of air in the intake channel. Swirling flow has abilities to improve fuel/air mixing efficiency, increasingcombustion intensity and stabilizing the combustion flame and also raising the flame propagation speed thus theeffective combustion can be achieved. Turbo Cyclone installation will affect its airflow characteristics, e.g. turbulenceintensity and pressure drop. The blade design has a great effect to the magnitude of turbulence intensity and pressuredrop. The CFD simulation shows that turbo cyclone installation does have effect to the turbulence intensity andpressure drop. Further analysis with blade design variation gives the results that the wider blade angle the bigger itsturbulence intensity and so does the pressure drop. Turbo Cyclone without holes on its blades also has morecontribution in raising those two parameters than Turbo Cyclone with holes on its blades. In this case model 7 has thelargest turbulence intensity and pressure drop at all air inlet velocity, that is 105,32 Pa and 1,52 at air inlet 6,099 m/s,570,45 Pa and 3,62 at air inlet 14,52 m/s, and also 937,73 Pa and 4,64 at air inlet 18,634 m/s.
KAJI EKSPERIMENTAL PENGARUH TEMPERATUR BIODIESEL MINYAK SAWIT TERHADAP PERFORMANSI MESIN DIESEL DIRECT INJECTION PUTARAN KONSTAN Fajar, Berkah; Utomo, Tony Suryo; Murni, Murni
ROTASI Volume 11, Nomor 3, Juli 2009
Publisher : Departemen Teknik Mesin, Fakultas Teknik, Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (143.674 KB) | DOI: 10.14710/rotasi.11.3.28-31

Abstract

The imperfect combustion process will be a problem in the development effort of diesel engine’sperformance. Nonhomogen air–fuel mixing process is one of the factors which cause the imperfectcombustion.By heating up the diesel biodiesel up to a certain temperature before it goes through thehigh pressure injection pump will lower its density and viscosity. Therefore, when injected in thecombustion chamber, it will formed smaller droplets of fuel spray which result in a morehomogenious air–fuel mixture. Also by using higher temperature will make the diesel fuel easier toignite in order to compensate the limited time which is available in high speed operating conditions.Diesel engine Dong Feng 1 cylinder direct injection at constant speed was used in this research. Thefuel used are biodiesel with temperature variations in the range from 33oC to 90oC . The best thermalefficiency for biodiesel fuel is 25.3 % at 70oC with 28 % BSFC. In this condition, the fuelconsumption was decreased 8 % by comparing with that at 33oC.
Use Of Machine Learning With The Long Short Term Memories Method As The Basis For Cleaning And Performance Of Steam Turbine Condensers For Gas And Steam Power Plants Utomo, Tony Suryo; Christwardana, Marcelinus; Syachrir, Guntur
Journal of World Science Vol. 4 No. 5 (2025): Journal of World Science
Publisher : Riviera Publishing

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.58344/jws.v4i5.1411

Abstract

This research focuses on the design of a bidirectional reinforced concrete slab for a 5-storey apartment building located on Jalan Pemuda, Semarang, following SNI 1726:2019 standards. The objective is to compare the results of the direct design method (DDM) using Excel with ETABS v18 software, analyzing the accuracy of traditional methods in modern structural designs. The study employed a practical approach, incorporating various design parameters such as beam dimensions, span length, dead and live loads, and material strengths (f'c and fy). The results indicate that although there is a slight difference between the methods, they exhibit similar trends. The study found that increased load leads to higher moments, while larger beams and higher concrete strength reduce reinforcement requirements. However, discrepancies between the methods were observed due to rounding errors in the DDM. The research suggests refining moment calculation techniques and enhancing software tools for more accurate slab designs. The findings are essential for improving design accuracy in both academic and professional practice, particularly for earthquake-resistant structures.