FTUI Doctoral Candidate Developed a Basic Dynamic Characteristic Model of Winding River

Dr. Dwinanti Rika Marthanty from Civil Engineering FTUI, presented her dissertation entitled “The Smoothed  Particle Hydrodynamics Method Development for Basic Dynamics Modeling Characteristic of Winding River” during her Doctoral Candidate Inauguration which took place on 15 June 2016 in the Cheveron Room, Dean’s Building FTUI. Acting as Head of Examiner Committee is the Dean of FTUI, Prof. Dedi Priadi, DEA with Dr-Ing Dwita Sutjiningsih as Promotor; and Co-Promotor Herr Soeryantono, Ph.D. Examiner Committee includes Prof. Iwan Kridasantausa Hadihardjaja; Dr. Ahmad Indra Siswantara and Alhadi Bustaman, Ph.D. Several France researchers are also involved in this research. They are: Prof. Erick CALIER and Prof. Isam SHAHROUR from Universite Lille 1, France and Prof. Hassan SMAOUJI from Universite Technologie de Compeigne, France.

Generally, this research is divided into two discussions: (1) the determination of basic dynamic characteristic meander using RMA, done in France; and (2) the development of SPH (Smoothed Particle Hydrodinamics) method for the helical flow in waving channel, done in Indonesia.

The main propose of this research is finding out where the pattern of helical flow from the flow simulation done with RMA is in comparison with the SPH method. The waving phenomenon is caused by turbulence and can be explained by the flow structure. The meander flow need to be simulated in 3D to sho the primary flow structure and the secondary flow, including the helical flow. One of the method used for 3D flow model is the Finite Element Method (FEM).

This research used the RMA (Resources Modeling Association) model to simulate the 3D flow simulation based on FEM. However, according to Marlin et.al (2007), FEM’s drawback is in the modeling of 3D flow surface water system, especially in limited computing ability and simple geometric limit condition. More promising and newer method is the smoothed particle hydrodynamics (SPH).

Gomez-Gesteira, et al., (2010) promoted that SPH is able and more suitable in modeling flow with atmospheric pressured surface. Based on the above reasoning, this research suggest the use of SPH method to simulate the meander flow simulation. Then, comparing the SPH result with the RMA result.

In writing the research, the development of SPH was focused on the development of similar and comparable flow pattern produced quantitatively by RMA. The result of SPH and RMA is then compared with laboratory testing results done by Wang and Liu (2015).

The SPH method is explained as the whole process from work equation, discretization method, and numeric solution. The next chapter presented the SPH algorithm which was divided into two steps: (1) 3D flow calculation, and (2) particle interaction between liquid and solid or referred to as the controlled collision between water particles and wall.

The conclusion of this research is (1) basic meander dynamic characteristic is the helical flow, (2) viscosity and vorticity plays an important role in developing the helical flow in meander channel, (3) the helical flow pattern of the SPH model by comparing with the RMA result, (4) SPH pattern consistency with the pattern from Wang and Liu trial result (2015), and (5) SPH method is able to modeling the 3D helical pattern realistically in meander channel.

As closure, the last chapter concluded from two discussions where (1) RMA can be used to simulate the basic characteristics of meanders flow and the main characteristic of meanders dynamics is the helical flow, and (2) the development of SPH method was focused on the formation of helical flow in meander channel. The form of helical flow as a result of SPH can be compared generally with RAM result and the result of laboratory test done by Wang and Liu in 2015.

The contribution this research is to participate in the development of SPH to be used in: (1) limited condition by using simple geometric with particles interaction based on Snell law, and (2) adaptation in  adjusting the equation with the 3D ‘almost comprehensible’ flow condition for the 3D incomprehensible flow condition in meander channel. (Civil Engineering Department FTUI).