STUDY OF WATER JET PROPULSION SYSTEM DESIGN FOR FAST PATROL BOAT (FPB-60) Arica Dwi SUSANTO, U.B. PRIHANTO, AHMADI, Okol S SUHARYO, Adi BANDONO* *Indonesian Naval Technology College, STTAL, Bumimoro-Morokrembangan, Surabaya 60187, Indonesia FPB-60 is a type of patrol boat built by shipyard in Indonesia to strengthen the needs of water territorial. However, the 20 years age caused a decrease in performance of the vessel. The method used was the harvard guldammer method to calculate water jet system parameters at a maximum velocity of 35 knots such as inlet diameter and nossel diameter, pump power, pump type used and other parameters to obtain Overall Propulsive Coefficient at that speed. In the calculation of water jet propulsion system design, the amount of capacity generated water jet pump system obtained was 4.15 m3 / s with flow velocity on the nozzle/jet of 28.8 m/s. Based on the value of specific swabs of suction (Nss) of 6205.49, the pump for the water jet propulsion system had considered fulfilled the cavitation limit requirement so that it could be used for (FPB-60). Keywords: Vessel Resistance, Water Jet, Power, FPB. 1. INTRODUCTION compared to ships that use propellers so that with an increase FPB-60 is a type of patrol boat in thrust generated by the engine it built by a shipyard in Indonesia to will be able to produce higher strengthen the needs of water vessel speed (Herdzik 2013). territorial. However, the 20 years This paper have many age cause a decrease in supporting its research, for example performance of the vessel. Based on paper with title An Approximate these demands, it is necessary to Method For Calculation of Mean have a ship that has good, safe Statistical Value of Ship Service acceleration and maneuverability, Speed on a Given Shipping Line, and has a low boat load so that it Useful in Preliminary Design Stage can be operated in deep or shallow (Żelazny 2015), Experimental waters (Susanto.et.al. 2017). Investigation on Stern-Boat With the use of a water jet Deployment System and propulsion system, the vessel can Operability For Korean Coast be cultivated to have a smaller load Guard Ship (Chun.et.al. 2013), Page 135 Performance of VLCC Ship with Free Surface Flow over a Container Podded Propulsion System and Vessel Using CFD Rudder (Amin 2014). Introduction (Atreyapurapu.et.al 2014). to Naval Architecture (Tupper Empirical Prediction of Resistance 1975). Basic Ship Theory (Tupper of Fishing Vessels (Kleppesto 2001). Practical Ship Design 2015). Designing Constraints in (Watson 1998). Ship Resistance and Evaluation of Ship Propulsion Propulsion : Practical Estimation of Power (Charchalis 2013). Ship Propulsive Power (Anthony F. Coefficients of Propeller-hull Molland 2011). Practical Ship Interaction in Propulsion System of Hydrodynamics (Bertram 2000). Inland Waterway Vessels with Effect of Fluid Density on Ship Stern Tunnels (Tabaczek 2014). Hull Resistance and Powering Cost optimization of marine fuels (Samson 2015). Ship Design and consumption as important factor of Construction (D'arcalengelo 1969). control ship’s sulfur and nitrogen Resistance Propulsion and Steering oxides emissions (Kowalski 2013). of Ship (WPA Van Lamerren Numerical Investigation of the 1984). Predictive Analysis of Bare- Influence of Water Depth on Ship Hull Resistance of a 25,000 Dwt Resistance (Premchand 2015). The Tanker Vessel (Adumene 2015). Wageningen Propeller Series Resistance and Propulsion of Ships (Kuiper 1992). Principles of Naval (Harvald 1992). Hydrodynamic of Architecture Second Revision Ship Propellers (Andersen 1994). (Lewis 1988). Marine Propulsion Ship Design for Efficiency and (Sladky 1976). Economy (Bertram 1998). Design In this paper, we used Harvard of Propulsion Systems for High- guldammer method to calculate Speed Craft (Bartee 1975). A water jet system parameters at method of Calculation of Ship maximum velocity of 35 knots such Resistance on Calm Water Useful at as inlet diameter and nossel Preliminary Stages of Ship Design diameter, pump power, pump type (Zelazny 2014). Increase of Ship used and other parameters to obtain Fuel Consumption Due to the the Overall Propulsive Coefficient Added Resistance in Waves at that speed (Kim 1966). With this (Degiuli.et.al. 2017). An paper, it was expected that the Investigation Into The Resistance water jet propulsion system could Components of Converting a be used as an alternative for patrol Traditional Monohull Fishing boats to be built and operated in Vessel Into Catamaran Form accordance with their duties. (Samuel 2015). Simulation of a Page 136 This Paper is organized as 2.2. Water Jet Propulsion on follows. Section 2 is the review Fast Patrol Boat about basic ship theory. Section 3 The ship with water jet were description of results and propulsion is a ship which used research discussion. Finally, the water jet system as the propeller in conclusion of this paper is its operation in the water media so presented in section 4. that the ship can move in accordance with the speed of the 2. RESEARCH desired ship. Ships that use water METHODOLOGY jet propulsion system is a system consisting of bare hull system and 2.1. Propulsion System of The water jet system (Etter 1975). Ship The water jet propulsion system The ship propulsion system, is is widely used primarily for high- the exact matching between prime speed vessels, because based on mover (diesel engine, gas turbine, studies that have been conducted, it steam turbine) and propeller from was showed that the water jet ship. Matching completion is not propulsion system has a feature that only seen from the engine or has nothing to do with its propeller point of view, but both are propulsive efficiency. Some of the an integrated problem (Etter 1975). features that the water jet propulsion system possesses are Nomenclature described below: After Perpendicular (AP) 1. The absence of propellers Fore Perpendicular (FP) and steering outside the Length between perpendicular (Lpp) vessel is very advantageous Length on the water line (Lwl) Length Overall (Loa) because it reduces the total Breadth molded (B/Bmld) resistance occurring on the Draft/draught (T) vessel and allows the Dept (H) operation of vessels for Freeboard (F) shallow waters. Centre line (CL) Speed of The Ship (Vs) 2. Have good acceleration Ship Resistance (R) ability. Effective Horse Power (EHP) 3. Have good ship motion Thrust Horse Power (THP) when the vessel speed is Delivery Horse Power (DHP) relatively low. Shaft Horse Power (SHP) Brake Horse Power (BHP) 4. Have the advantage when the ship is in movement at a relatively high speed. Page 137 5. Placement of impeller inside b. Calculation of required ship body will be able to power and total resistance reduce vibration and noise used Harvarld Guldhamer level on ship. method. 6. At a relatively high velocity c. The planning of the water of the vessel, propulsive jet propulsion system started efficiency can be maintained by taking the Overall high enough to be Propulsive Coefficient comparable to the propeller (OPCo) as a first step to propulsion system. calculate the parameters of the water jet propulsion system until the OPC was obtained in accordance with the predefined OPCo. Thereafter, calculations of the cavitation requirements of the channel system and Fig. 1 Water jet System the propulsion pump were Configuration used. 2.3. Cavitation Requirements 3. RESULT AND The evaporation of these liquids DISCUSSION can occur inside the pump or channel due to high flow velocity 3.1 Vessel Data (turbulent flow) which can cause The data from Fast Patrol Boats the pumped fluid temperature to be (FPB-60) to be used as calculations higher. At the pump, the cavitation in the planning of water jet problem often occurs on the suction propulsion system were as follows: side when the pump suction a. LOA :60 m pressure is too low or under it b. LWL saturation pressure (Barrass 2004). : 55 m c. Breadth (B) 2.4. Method of Research. : 8,10 m The planning of the water jet d. Draft (T) propulsion system is based on the : 2,46 m following matters e. Height (H2) a. The ship data used was : 4,86 m Fast Patrol Boats (FPB-60) f. Block Coefficient to be built (Cb) : 0,350 Page 138 g. Velocity (Vs) OPC price of 0.57, the amount of : 35 knot BHP could be calculated as follows: T Vs BHP = h × 3.2. Resistance Calculation z OPC 99,17 The magnitude of the = ,49 765× resistance on the ship at the planned ,0 57 vessel velocity of 35 knots or =1570,65 KW 17.99m / s was: In this water jet system,it was a. Frictional Resistance planned that the pump impeller : 82, 463 KN would be driven by a motor with b. Residual Resistance direct clutch transmission, with : 1,16 KN transmission efficiency between c. Wind Resistance 0.96 - 0.99 per pump. In this :3,686 KN planning, the value was 0.96 so the d. Additional amount of SHP could be calculated Resistance :12,22 KN as follows: So the total resistance that occurs SHP =ηT x BHP on the ship was 99.53 KN. =0,96 x 1570,65 =1507,82 KW 3.3. EHP, BHP and SHP Calculation 3.4. Discussion Based on the total resistance, the amount of effective thrust required 3.4.1. Dimension and Water Jet to be able to move the ship in System Parameter Calculation accordance with the planned speed As shown in the figure below, could be calculated as follows: based on the amount of thrust per EHP =RT x Vs SHP in the unit (lbf / HP), the =99,53 x 17,99 amount of power density (SHP / =1790,55 KW Di2) in units (HP / cm2) could be This plan was assumed to be in known.