This research is proposed to study the effect of wave condition to the distance between floating structures which arranged in tandem arrangement. The evaluation on the gap distance between floating structures is an important study for offshore liquefied natural gas, LNG offloading system because small gap distance between floating structures is needed to guarantee the effectiveness of LNG transfer from FPSO to ship but collision between floating structures should be avoided. Therefore, the gap distance between floating structures becomes a main factor to ensure the safety of the arrangement and effectiveness of the offloading system. Model experiment in regular wave condition was carried out to analyze the motion of floating structures and the effect of wave on changing of gap distance between structures. The time domain motion data are measured by Qualisys Camera and then Fourier Transformation method is applied to transform the data to frequency domain for further analysis. The frequency domain data is utilized in this research to find the tendency of gap distance between floating structures due to the effect of structures response and wave condition. From the study, an empirical equation to simulate the minimum gap distance between floating structures is introduced.
Aeronautics, Automotive and Ocean Engineering, Universiti Teknologi Malaysia, Malaysia
Ocean and Aerospace Engineering Research Institute, Indonesia
For the design of safe and economic offshore structure the knowledge of the wave environment and related wave-structure interactions is required. In general, frequency domain analysis has been regarded as an adequate tool for the assessment of motion and loads which are needed to derive the stress and hydrodynamics forces as well as operational limitations. For investigating the behavior of response to specific sea conditions, this research analyzes the behavior of the response due to motion and wave forces as well as hydrodynamics with focus on a type square column. The frequency domain investigation has used to provide the response behaviors on the wetted body of the semi-submersible in regular waves. For investigation,, the selected sea condition for regular wave is generated in a physical wave tank, and the behavior of the response on the semi-submersible is evaluated at model scale. Equation of motion was formulated to evaluate the added mass, dampi ng and stiffness at every frequency step. In frequency domain analysis, the hydrodynamics responses were obtained.
Aeronautics, Automotive and Ocean Engineering, Universiti Teknologi Malaysia, Malaysia
The decreased world fossil energy reserve, in general, and specifically in Indonesia requires us to find alternative energy resources. Biomass is one of alternative energies with great potential in Indonesia. One of it is Candlenuts Shell (CNS) as the waste of candlenuts fruit, with the production 89,155 tons/year will produce 207,958 tons shell/year. Candlenut shells are made into briquette with particle size < 1 mm, and then burnt in combustion test instrument with variations raw material composition of biomass and biomass charcoal. Mass reduction of each variable is measured using digital scale include RS232 that is connected to computer, burning gas temperature by using thermocouple. In terms of burning rate, generated energy and gas temperature the best raw material composition is 75% of biomass raw material and 25% of biomass charcoal.
Department of Mechanical Engineering, Medan State University, Indonesia
Department of Mechanical and Industrial Engineering, Gadjah Mada University, Indonesia
Department of Mechanical Engineering, Janabadra University, Indonesia
Indonesian traditional ship is a product of an indigenous technology developed long before the advent of western culture along the Coast of Sulawesi Island. The ships are built traditionally in both method and equipment without any sketches or calculations. Advancement in science and technology, and abundant information available on the World Wide Web has caused unprecedented changes in many areas of human Endeavour. However, Indonesian traditional ship builders have not taken full advantage of available technology and information particularly in the preparation of lumber which remains one of the critical and most unpredictable stages in construction. This study addressed the issue of delays which is always one of the critical issues confronting the construction of traditional ship in Kepulauan Riau. A low cost air drying model was proposed. The model was tested by comparing the air drying time of lumber in two specific conditions. Four different sample s of lumber were used to test the efficiency of both the air drying model and the natural air drying technique. In conclusion, the proposed model having applied and compared with the traditional method clearly show a better method.
Aeronautics, Automotive and Ocean Engineering, Universiti Teknologi Malaysia, Malaysia
Ocean and Aerospace Engineering Research Institute, Indonesia
