Study of Water Jet Propulsion System Design For Fast Patrol Boat (Fpb-60) Arica Dwi Susanto 1, U.B. Prihanto 2

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1 Study of Water Jet Propulsion Syste Design For Fast Patrol Boat (Fpb-60) Arica Dwi Susanto, U.B. Prihanto Indonesian Naval Technology College, STTAL. Buioro-Morokrebangan, Surabaya 6087, Indonesia Abstract: (FPB-60) is a type of patrol boat built by shipyard in Indonesia to strengthen the needs ofwater territorial.however, the 0 years age caused a decrease in perforance of the vessel. The ethod used was the harvard guldaer ethod to calculate water jet syste paraeters at a axiu velocity of 35 knots such as inlet diaeter and nossel diaeter, pup power, pup type used and other paraeters to obtain Overall Propulsive Coefficient at that speed. In the calculation of water jet propulsion syste design, the aount of capacity generated water jet pup syste obtained was / s with flow velocity on the nozzle/jet of 8.8 /s. Based on the value of specific swabs of suction (Nss) of , the pup for the water jet propulsion syste had considered fulfilled the cavitation liit requireent so that it could be used for (FPB-60). Keywords: Vessel Resistance, Water Jet, Power, FPB.. INTRODUCTION (FPB-60) is a type of patrol boat built by a shipyard in Indonesia to strengthen the needs of water territorial. However, the 0 years age cause a decrease in perforance of the vessel. Based on these deands, it is necessary to have a ship that has good, safe acceleration and aneuverability, and has a low boat loadso that it can be operated in deep or shallow waters (Susanto.et.al. 07). With the use of a water jet propulsion syste, the vessel can be cultivated to have a saller load copared to ships that use propellers so that with an increase in thrust generated by the engine it will be able to produce higher vessel speed (Herdzik 03). This paper have any supporting its research, for exaple paper with title An Approxiate Method For Calculation of Mean Statistical Value of Ship Service Speed on a Given Shipping Line, Useful in Preliinary Design Stage (Żelazny 05).Experiental Investigation on Stern- Boat Deployent Syste and Operability For Korean Coast Guard Ship (Chun.et.al. 03). Perforance of VLCC Ship with Podded Propulsion Syste and Rudder (Ain 04). Introduction to Naval Architecture (Tupper 975). Basic Ship Theory (Tupper 00). Practical Ship Design (Watson 998). Ship Resistance and Propulsion : Practical Estiation of Ship Propulsive Power (Anthony F. Molland 0). Practical Ship Hydrodynaics (Bertra 000). Effect of Fluid Density on Ship Hull Resistance and Powering (Sason 05). Ship Design and Contruction (D'arcalengelo 969). Resistance Propulsion and Steering of Ship (WPA Van Laerren 984). Predictive Analysis of Bare-Hull Resistance of a 5,000 Dwt Tanker Vessel (Aduene 05). Resistance and Propulsion of Ships (Harvald 99). Hydrodynaic of Ship Propellers (Andersen 994). Ship Design for Efficiency and Econoy (Bertra 998). Design of Propulsion Systes for High-Speed Craft (Bartee 975). Aethod of Calculation of Ship Resistance on Cal Water Useful at Preliinary Stages of Ship Design (Zelazny 04). Increase of Ship Fuel Consuption Due to the Added Resistance in Waves (Degiuli.et.al. 07). An Inventigation Into The Resistance Coponents of Converting a Traditional Monohull Fishing Vessel Into Cataaran For (Sauel 05). Siulation of a Free Surface Flow over a Container Vessel Using CFD (Atreyapurapu.et.al 04). Epirical Prediction of Resistance of Fishing Vessels (Kleppesto 05). Designing Constraints in Evaluation of Ship Propulsion Power (Charchalis 03). Coefficients of Propeller-hull Interaction in Propulsion Syste of Inland Waterway Vessels with Stern Tunnels (Tabaczek 04). Cost optiization of arine fuels consuption as iportant factor of control ship s sulfur and nitrogen oxides eissions (Kowalski 03). Nuerical Investigation of the Influence of Water Depth on Ship Resistance (Prechand 05). The Wageningen Propeller Series (Kuiper 99). Principles of Naval Architecture Second Revision (Lewis 988). Marine Propulsion (Sladky 976). In this paper, we used harvard guldaer ethod to calculate water jet syste paraeters at axiu velocity of 35 knots such as inlet diaeter and nossel diaeter, pup power, pup type used and other paraeters to obtain the Overall Propulsive Coefficient at that speed (Ki 966). With this paper, it was expected that the water jet propulsion syste could be used as an alternative for patrol boats to be built and operated in accordance with their duties. This Paper is organized as follows. Section is the review about basic ship theory. Section 3 were description of result and research discussion. Finally, the conclusion of this paper is presented in section 4.. RESEARCH METHODOLOGY.. Propulsion Syste of The Ship The ship propulsion syste, which is the exact atching between prie over (diesel engine, gas turbine, stea turbine) and propeller fro ship. Matching copletion

2 is not only seen fro the engine or propeller point of view, but both are an integrated proble (Etter 975). Fig. Longitudinal Shape of The Vessel Fig. Cross-sectional Shape of The Vessel Fig. 3 Propulsion Syste of The Vessel Noenclature After Perpendicular (AP) Fore Perpendicular (FP) Length between perpendicular (Lpp) Length on the water line (Lwl) Length Overall (Loa) Breadth oulded (B/Bld) Draft/draught (T) Dept (H) Freeboard (F) Centre line (CL) Speed of The Ship (Vs) Ship Resistance (R) Effective Horse Power (EHP) Thrust Horse Power (THP) Delivery Horse Power (DHP) Shaft Horse Power (SHP) Brake Horse Power (BHP).. Water Jet Propulsion on Fast Patrol Boat The water jet propulsion syste has been used as a booster for fast boats over three hundred years ago, but its use is widely knocked on its low propulsive efficiency when copared to ship propulsion systes that use conventional propellers. The ship with water jet propulsion is a ship which used water jet syste as the propellerin its operation in the water edia so that the ship can ove in accordance with the speed of the desired ship. Ships that use water jet propulsion syste is a syste consisting of bare hull syste and water jet syste (Etter 975). Bare hull syste is a shipbuilding body with no water jet installed. However, in the calculation of weight and the position of center of gravity should be the weight of the ship in a state of operation at sea, so it ust be included along with the weight of water entering through the water jet syste (entrained water). The water jet propulsion syste generally consists of a pup and a ducting systesyste. The pup syste serves to convert echanical power into hydraulic power. While the channel syste serves to direct the flow rate fro the environent to the pup and fro the pup to return to the environent. The water jet propulsion syste is widely used priarily for high-speed vessels, because based on studies that have been conducted, it wasshowed that the water jet propulsion syste has a feature that has nothing to do with its propulsive efficiency. Soe of the features that the water jet propulsion syste possesses are described bellow:. The absence of propellers and steering outside the vessel is very advantageous because it reduces the total resistance occurring on the vessel and allows the operation of vessels for shallow waters.. Have good acceleration ability. 3. Have good shipotion when the vessel speed is relatively low. 4. Have the advantage when the oveent of the ship at a relatively high speed ship. 5. Placeent of ipeller inside ship body will be able to reduce vibration and noise level on ship. 6. At a relatively high velocity of the vessel, propulsive efficiency can be aintained high enough to be coparable to the propeller propulsion syste.

3 knot d. Draft (T) :,46 e. Height (H ) : 4,86 f. Block Coefficient (Cb) : 0,350 g. Velocity (Vs) : 35 Fig. 4 Water jet Syste Configuration.3. Cavitation Requireents Cavitation is a sypto of fluid evaporation that is flowing because the pressure is reduced to below the saturation pressure so that the stea bubble would be for and interfere with the work of the pup. The evaporation of these liquids can occur inside the pup or channel due to high flow velocity (turbulent flow) which can cause the puped fluid teperature to be higher. At the pup, the cavitation proble often occurs on the suction side when the pup suction pressure is too low or under it saturation pressure (Barrass 004). If the pup is cavitated, it will create noise and vibration that will eventually lead to a decrease in perforance of the pup. In order for the pup to be safe against cavitation probles, the pup ust have a specific suction rotation price which is below the cavitation liit of the pup. The specific rotation price of the suction will be greatly influenced by the agnitude of the Net Positive Suction Head (NPSH) of the pup used..4. Method of Research. The planning of the water jet propulsion syste is based on the following atters a. The ship data used was Fast Patrol Boats (FPB- 60) to be built b. Calculation of required power and total resistance used Harvarld Guldhaer ethod. c. The planning of the water jet propulsion syste started by taking the Overall Propulsive Coefficient (OPCo) as a first step to calculate the paraeters of the water jet propulsion syste until the OPC was obtained in accordance with the predefined OPCo. Thereafter, calculations of the cavitation requireents of the channel syste and the propulsor pup were used. 3. RESULT AND DISCUSSION. 3. Vessel Data The data fro Fast Patrol Boats (FPB-60) to be used as calculations in the planning of water jet propulsion syste were as follows: a. LOA : 60 b. LWL : 55 c. Breadth (B) : 8,0 3.. Resistance Calculation The agnitude of the resistance on the ship at the planned vessel velocity of 35 knots or 7.99 / s was: a. Frictional Resistance : 8, 463 KN b. Residual Resistance :,6 KN c. Wind Resistance : 3,686 KN d. Additional Resistance :, KN So the total total resistance that occurs on the ship was KN EHP, BHP and SHP Calculation Based on the total resistance, the aount of effective thrust required to be able to ove the ship in accordance with the planned speed could be calculated as follows: EHP RT x Vs 99,53 x 7,99 790,55 KW This plan was assued to be in an ideal state so that the aount of thrust required was equal to the aount of total resistance that occurred. The water jet propulsion syste was planned to use two pups of propulsor so that the aount of thrust per pup was 49,765 KN. By taking the initial OPC price of 0.57, the aount of BHP could be calculated as follows: BHP T h z Vs OPC 7,99 49,765 0,57 570,65 KW In this water jet syste,it was planned that the pup ipeller would be driven by a otor with direct clutch transission, with transission efficiency between per pup. In this planning, the value was 0.96 so the aount of SHP could be calculated as follows: SHP η T x BHP 0,96 x 570,65 507,8 KW 3

4 3.4. Discussion Diension and Water Jet Syste Paraeter Calculation As shown in the figure below, based the aount of thrust per SHP in the unit (lbf / HP), the aount of power density (SHP / Di ) in units (HP / c ) could be known. 8.8 s The aount of flow capacity in the jet / nozzle: Q J Vj x An 8,8 x 0,45 4,5 3 /s The coparison of ship speed and flow velocity through the jet could be expressed by: Vj Vs 8,8 7,99 0,65 j ideal The aount of ideal jet efficiency : η j. 0,65 0,65 0,769 Fig. 5 Chart of Water jet Syste Inlet Diension The aount of thrust per SHP was 5.48 so based on the picture above, the aount of power density at was obtained. Fro power density, the ain diensions of water jet syste could be calculated as follows: Inlet Diaeter : 0,668 Inlet Area : 0,350 Nossel diaeter : 0,430 Nossel Area : 0,45 By taking the fraction of the current flow value of 0.05, we could get the inlet speed as follows: : Vi ( w) x Vs ( 0,05) x 7,99 7, 09 /s So the aount of speed on the outlet or nozzle (Vj) could be obtained by: Vj 4. T 0,5 Vi Vi. An ,5 7,09 7,09 04,63 0,44 For the planning of the water jet propulsion syste, it was recoended that the value of inlet loss coefficient (ψ) was set between 6% - 0%. In this calculation, the value of inlet loss was 8%, because the water jet syste used a flush inlet type and the vessel operated in a relatively clean area of water. Meanwhile, the value of loss coefficient (ζ) was recoended between % - 4%. In the calculations for actual jet efficiency, a value of % was chosen because the losses on the nozzle were relatively saller copared to their inlet channels. So, the actual j aktual jet efficiency cost for the water jet syste could be obtained by: 0,05 ηj aktual.. w.. g hj Vj. 0,0 0,8 0,769 0,769 0,769 9,8 0,88 8,8 0,675 In the calculation of the overall propulsion efficiency (OPC), it was assued that the pup efficiency was 0.89 and the relative rotative efficiency was So, 4

5 the overall propulsion efficiency (OPC) could be obtained by: OPC jaktual x η P x η r x η T 0,675 x 0,89 x 0,98 x 0,96 0,573 0,57 Based the calculation of Overall Propulsive Coefficient (OPC),an equal value to the previous forecast was obtained so that the calculation could be continued Calculation of Pup Characteristic: a. Pup Rotation N K x SHP (/3) 69 x 00,45 (/3) 873, Rp b. Specific Rotation The flow capacity (Qj) obtained fro the previous calculation was 4.5 (3 / s) (ft3 / s) converted into gallon units per inute (GPM) to be obtained at GPM. The aount of price for pup Head could be calculated as follows: V H j Vi hlt g g 0,769 8,8 0, 88 9,8 3,66 03,84 ft Specific rotation value of suction could be calculated as follows: Nss N NPSH ,48 Q j 6573,06 03,84 Based on the iage of the Operation Zone of the Mixed Flow Pup below, the planned operating zone of the water jet pup syste was located in zone I or continuous operation zone, which was separated by zone II by Nss 000 line as the cavitation boundary. This eans that the pup for the planned water jet syste et the allowable cavitation requireents so it was safe to use continuously. 8,8 7,09 9,8 9,8 5,88 33,5 09,06 ft So the value of pup specific rotation could be calculated as follows: Ns N Q j H ,06 09, ,69 Based on the specific rotation value of the pups obtained above, the type of pup to be used that corresponds to the specific value of the round was the type of ixed flow pup with a specific rotation between 4000 <Ns <0000 c. Suction Specific Rotation The value of NPSH could be calculated as follows: NPSH ideal Vj j. hj g Fig. 6 Mix Flowed Pup Operation Zone 4. CONCLUSION Based on the calculations,it required propulsor pup drive with power of 57 KW and round 874 RPM per pup to obtain the axiu planned speed. Based on the result of specific rotation of 6639,69 then the type of pup used in accordance with the specific rotation size is Mixed Flow Pup (4000 <Ns <0000). The thrust force generated by the water jet propulsion syste was highly dependent on the aount of flow capacity generated by the pup used. The larger the capacity produced by the pup with a constant 5

6 nozzle diaeter, the nozzle flow rate will also be greater so that the resulting thrust would also be greater. In the planning of water jet propulsion syste is obtained the aount of capacity generated water jet pup syste is / s with flow velocity on the nozzle / jet of 8.8 / s. Fro the value of specific swabs of suction (Nss) obtained that is equal to then the pup for the water jet propulsion syste has fulfilled the cavitation liit requireents so that it can be used continuously (continuous). In this water jet propulsion syste plan, the aount of capacity generated by water jet pup syste was obtainedat /s with flow velocity on the nozzle / jet of 8.8 /s. Based on the value of specific rotation of suction (Nss) obtained at ,it could be concluded that the pup for the water jet propulsion syste had fulfilled the cavitation liit requireents so that it could be used continuously. 5. ACKNOWLEDGEMENT This research has been Supported by Indonesia Naval Technology College (STTAL). REFERENCES Aduene, NSAS 05, 'Predictive Analysis of Bare-Hull Resistance of a 5,000 Dwt Tanker Vessel', International Journal of Engineering and Technology, pp Ain, JKAA 04, 'Perforance of VLCC Ship with Podded Propulsion Syste and Rudder', International Society of Ocean, Mechanical and Aerospace Scientists and Engineers, pp. -7. Andersen, JP 994, Hydrodynaic of Ship Propeller, Elsevier, Cabridge. Anthony F. Molland, SR 0, Ship Resistance and Propulsion, Practical Estiation of Ship Propulsive Power, United Stated of Aerica. Atreyapurapu.et.al, K 04, 'Siulation of a Free Surface Flow over a Container Vessel Using CFD', International Journal of Engineering Trends and Technology, pp Barrass, C 004, 'Ship Design and Perforance for asters and Mates', Elsevier. Bartee, DL 975, 'Design of Propulsion Systes for Hidh- Speed Craft', The Society of Naval Architects and Marine Engineers, pp. -7. Bertra, HSAV 998, Ship Design for Efficiency and Econoy, Butterworth-Heineann, Great Britain. Bertra, V 000, Practical Ship Hydrodynaic, Great Britain, Inggris. Charchalis, A 03, 'Designing Constraints in Evaluation of Ship Propulsion Power', Journal of KONES Powertrain and transport, pp. -6. Chun.et.al., HH 03, 'Experiental investigation on sternboat deployent syste and operability for Korean coast guard ship', International Journal Naval Architecture Ocean Engineering, pp D'arcalengelo, AM 969, Ship Design and Contruction, Professor of Naval Architecture and Marine Engineering University of Machigan, Michigan. Degiuli.et.al., N 07, 'Increase of Ship Fuel Consuption Due to the Added Resistance in Waves', Journal of Sustainable Developent of Energy, Water and Environent Systes, pp. -4. Etter, RAB&RJ 975, 'Selection of Propulsion Systes for High Speed Advanced Marine Vehicles ', SNAME. Etter, RJ 976, Water Jet Propulsion An Interview, The Winter Annual Meeting of The Aerican Society of Marine Engineers, New York. Harvald, SA 99, Resistance and Propulsion of Ships, John Wiley and Sons, New York. Herdzik, J 03, 'Probles of propulsion systes and ain engines choice for offshore support vessels', Scientific Journals Zeszyty Naukowe, vol, no , pp Jeng-Horng Chen, C-CC 006, 'A Moving PIV Syste For Ship Model Test in Towing Tank', Journal Ocean Engineering, pp Joe Longo, FS 005, 'Uncertainty Assessent For Towing Tank Tests With Exaple For Surface Cobatant DTMB Model 545', Journal of Ship Research, pp Ki, HC 966, 'Hydrodinaic Aspect of Internal Pup Jet', Marine Technology. Kleppesto, K 05, 'Epirical Prediction of Resistance of Fishing Vessels', NTNU Trondhei Norwegion University of Science And Technology, pp Kowalski, A 03, 'Cost optiization of arine fuels consuption as iportant factor of control ship s sulfur and nitrogen oxides eissions', Scientific Journals, pp Kuiper, G 99, The Wageningen Propeller Series, MARIN, Netherland. Lewis, EV 988, Principles of Naval Architecture Second Revision, The Society of Naval Architecs and Marine Engineers, New Jersey. M. Reichel, AMANLL 04, 'Tri Optiisation - Theory and Practice', the International Journal on Marine Navigation and Safety of Sea Transportation, pp Mohaad Pauzi Abdul Ghani, MNAR 008, 'The Prediction of Wake Wash in The Towing Tank', Jurnal Mekanika, pp Prechand, PK 05, 'Nuerical Investigation of the Influence of Water Depth on Ship Resistance ', International Journal of Coputer Applications, pp. -8. Sason, DIFAN 05, 'Effect of Fluid Density On Ship Hull Resistance and Powering', International Journal of Engineering Research and General Science, pp Sauel, MI 05, 'An Inventigation Into The Resistance Coponents of Converting a Traditional Monohull Fishing Vessel Into Cataaran For', International Journal of Technology, pp. -0. Sladky, J 976, Marine Propulsion, The Winter Annual Meeting of The Aerican Society of Marine Engineers, New York. 6

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