STUDI EKSPERIMENTAL DAN NUMERIK INTERFASIAL LAPISAN FILM PADA ALIRAN DUA FASE ANNULAR AIR � UDARA SEARAH KE BAWAH PIPA VERTIKAL

• Main Authors: , Barlian, , Ir. Samsul Kamal, M.Sc., Ph.D.
• 格式: Theses and Dissertations NonPeerReviewed
• 出版: [Yogyakarta] : Universitas Gadjah Mada 2013
• 主題: ETD
• 在線閱讀: https://repository.ugm.ac.id/123416/; http://etd.ugm.ac.id/index.php?mod=penelitian_detail&sub=PenelitianDetail&act=view&typ=html&buku_id=63527
• 機構: Universitas Gadjah Mada

Gas�liquid annular flow is a very commonly encountered two phase flow pattern. The liquid flows as a thin film forming an annular ��ring�� attached onto the channel wall. This flow configuration can be found in many industrial processes such as reactor core of nuclear power plant, U-tubes in steam generators and gas�oil transportation through long pipes. Presently, downward two-phase flow in vertical pipe has not been studied extensively in many literatures when compared to the horizontal and vertical upward flows. For that, there needs to be more research to find out more details about the interfacial phenomena that occur in annular downward two-phase flow on vertical pipe. The present work used digital image processing to provide non-intrusive direct visualization measurements of the liquid film in downward vertical air�water annular flow conditions in 19,1 mm ID tube and total pipe length of 8 meters. The images were processed to produce the distribution of film heights. The standard deviation and average film thickness have been determined experimentally with liquid and gas flow Reynolds numbers in ranges 2000 � 14.000 and 2000 � 13.000, respectively. Another important aspect of this investigation was wave frequency information that obtained by analysing the time-dependent image of film thickness for each of the two axial positions recorded. Wave velocities were calculated from the cross-correlating of the amplitude wave from the two axial positions. In addition, the pressure gradient was also measured to complement the data in calculating the friction coefficient and the interfacial shear stress. Finally, CFD validation was conducted for the average liquid film thickness. The results that shown variations of the gas-liquid Reynolds number for the minimum value on the average film thickness was 0,675 mm and the maximum value on the average film thickness was 1,727 mm. The results of CFD validation against experimental data were error results for liquid film thickness ± 15%.