International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-8 Issue-12, October 2019 5677 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: L39951081219/2019©BEIESP DOI: 10.35940/ijitee.L3995.1081219 Abstract: Post Swirl Stator (PSS), also known as the 'Energy Saving Device (ESD) Behind the Propeller' operates within the slip stream of the propeller. The aim of this project is to investigate the powering performance of a JAPAN Bulk Carrier (JBC) upon the installation of PSS. The prediction of resistance and propulsive factors were conducted using CFD simulation using SHIPFLOW CFD code. In order to find the optimised design of the ESD, three parameters were laid out and studied. The parameters are the left side fin length, right side fin length and the orientation of the fins.The aim of this study are to improvise the thrust fin design by changing the parameters to get the optimum powering performance result, and to quantify the powering performance of the JBC upon the installation of PSS in model and full scale. There were 27 different post-swirl stator configurations. All the 27 different configurations were compared in terms of its performance in model and full scale. All the 27 different configurations were simulated using full RANSE. The free surface of the water were modelled using panel method. A grid dependence study was conducted to determine the best grid cell resolution and it was chosen at a total of 7 millions cells. The bare hull resistance of the JBC were validated with available published experiment results. All the thrust fins were modelled using appendage setting in SHIPFLOW. The best thrust fins design were selected in judging its minimum drag, minimum thrust deduction fraction, minimum wake fraction, and the delivered power. It was found that he thrust fins design for case study #20 by CFD is the most optimised configuration in terms of its performance criteria as mentioned earlier. The thrust fins design was able to reduce delivered power to 6.012%. Thrust deduction was also reduced to 2.927%. Total efficiency was increased to 6.709%. Index Terms: Post-Swirl Stator, Energy Saving Device, CFD. I. INTRODUCTION Recently there are demands from shipowners to have their modern fleets to be equipped with energy saving devices (ESD). The major driving force in equipping ships with ESD is the push in getting higher Energy Efficient Design Index (EEDI). The EEDI is issued by the International Maritime Organization (IMO) to promote the use of energy efficient equipment, engines and devices to commercial vessels [1]. There are numerous ESDs that are being used namely Revised Manuscript Received on October 05, 2019. Iwan Mustaffa Kamal, Maritime Engineering Technology Section, Universiti Kuala Lumpur, Malaysian Institute of Marine Engineering Technology, Lumut, Perak, Malaysia. Md Salim Kamil, Maritime Engineering Technology Section, Universiti Kuala Lumpur, Malaysian Institute of Marine Engineering Technology, Lumut, Perak, Malaysia. Yaseen Adnan Ahmed, Maritime Engineering Technology Section, Universiti Kuala Lumpur, Malaysian Institute of Marine Engineering Technology, Lumut, Perak, Malaysia.. Nur Aqilah Elias, Maritime Engineering Technology Section, Universiti Kuala Lumpur, Malaysian Institute of Marine Engineering Technology, Lumut, Perak, Malaysia.. Mitsui duct [2], Grothues spoilers [3], Pre-swirl stators [4] etc. According to Carlton [5], ESDs are classified into three zone which are Zone 1: Before the propeller, Zone II: At the propeller, and Zone III: Behind the propeller. To date there are not many investigation on the performance of ESD used at Zone III. This ESD that is in the interest in this investigation is known as Post-Swirl Stator. It is believe that the Post-Swirl Stator could suppress the detrimental flow at the aft end of the propeller to improve rudder efficiency. In other words, this post-swirl stator is built as an attempt to deflect the flow from the propeller to turn the propeller‟s rotational components into useful axial flow. Min et al. [6] conducted a study using a post-swirl stator which consists of a rudder bulb and a pair of assymetrical thrust fins being fitted to the left and the right side of the rudder blade. Min et al. [6] has concluded in his study that the slipstream of the propeller produced asymmetrical flow due to the influence of the body of the ship. Due to this asymmetrical flow, the design of the thrust fin must be in asymmetrical shape to enhance thrust. This is shown in his work, where the design of the thrust fin chord and blade span at the right side of the rudder was larger than the the thrust fin attached at the left side of the rudder for a clockwise rotating propeller. It is found that an increase of propulsive efficiency of approximately 6% was obtained when the thrust fin is attached to a position aligned with the shaft centreline. When the thrust fin is attached to a position spaced apart from the shaft centerline in an upward direction by 15% of the propeller radius, the propulsive efficiency is increased at only 4%. Finally when the thrust fin is attached to a position to a position spaced apart from the shaft centerline in an upward direction by 30% of the propeller radius, the propulsive efficiency is increased at only 3%. Finally Min et al. [6] discussed that the he used a thrust fin with a length of 50% of the propeller radius for the left side fin and and 40% for the right side fin without discussing further on the effect of the fin‟s length to the propulsive efficiency. Even though there are some reports mentioning that the post-swirl devices as discussed earlier, could improve powering performance of a vessel, there are still a few challenges especially in determining the best configuration and the position of the post-swirl stator. Therefore, the main purpose of this study is to investigate the best configuration of the post-swirl devices for a typical bulk carrier. In this study a cape-size bulk carrier designed by the National Maritime Research Institute (NMRI) [7], was chosen as the test case. This bulk carrier is named Japan Bulk Carrier (JBC). The reason for this is there are abundance of measurement data of The Improvement of the Powering Performance on the Japan Bulk Carrier (JBC) using Rudder Thrust Fin as a Post-Swirl Stator Iwan Mustaffa Kamal, Md Salim Kamil, Yaseen Adnan Ahmed, Nur Aqilah Elias