The new S16R-S engine for fast passenger and utility craft

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CONSEIL INTERNATIONAL

INTERNATIONAL COUNCIL

DES MACHINES A COMBUSTION

_{ON COMBUSTION ENGINES}

20th INTERNATIONAL CONGRESS ON COMBUSTION SS

P.411

THE NEW S1 6R-S ENGINE FOR FAST

PASSENGER AND UTILITY CRAFT

by

T Harada, Y Ishida, I Ichihashi and FE ShiffiokouChi Mitsubishi Heavy Industries Ltdt

LONDON 1993

CYCIMAC 1991

THE NEW S16R-S ENGINE

FOR FAST PASSENGER AND UTILITY CRAFT

Tuneo HARADA

Yasuhiko ISHIDA **

Ichiro ICHIHASHI ***

Hiroko SHIMOKOUCHI ****

* Deputy Manager, Engine Engineering Department, MITSUBISHI HEAVY INDUSTRIES, LTD,

SAGAMIHARA MACHINERY WORKS ** Project Manager, Ditto *** Engineer, Ditto

**** Assistant Chief Engineer, Ditto

ABSTRACT

The S16R-S(60 V 16cyl. bore 170mm x stroke 180mm), _compact

high-performance diesel engine, has been developed especially _for

the mainpropulsion of high speed craft. Maximum continuous

ratings of up to 2100kw at 2000 r/min and overload ratings of up

to 2300kw at 2060r/min are available. A engine weight is _5500kg

and power to weight ratio is 2.6 kg/kw. The engine operates at

high mean effective pressure levels of 1.93 MPa at MCR.

This new S16R-S. engine has been developed

_from

_{existing Sl6R}

which is in production since 1989 _{as land and marine general use}

engine. In order to achieve much _{power and less weight from the}

Sl6R, engine performance simulation, thermal flow and stress

analysis were calculated. The _{rated output of new engine is}

increased up to 120% with the improvement, such as _constant

pressure turbocharging system applying newly developed

turbocharger, and revision in the injection _{system. The weight of}

engine is reduced to 89% from a original engine. _{This has been}

attained mainly by the adoption of aluminum _{parts and properly}

sized components.

The emphasis of this paper will be on the _calculation

analysis program, supercharging system, injection system, and

bench and field test program.

D26

1

1

RnSUM2

Le S16R-S (60°V 16 cyl. bore 170mm x stroke 180mm ) motuer

diesel compact de haute performance, A ete sprecialement congu

pour la propulsion principale des bateaux a haute vitesse. La

puissance continues maximales de pluo de 2100 kW,

a

2000 r/min,

et la puissance exessives de plus de 2300 kW

a

2060 r/min sont

disponibles. Le pods d'un moteur est de 5500 kg, et rapport du

poids et de la puissance est de 2.6 kg/kW.

Le moteur fonctionne de maniere optimale a un niveau de

pression de 1.93 MPa a MCR. Le nouveau moteur S16R-S

a

eta cree a

partir du S16R deja existant, en production depuis 1989, pour des

moteurs d'utilisation generale sur terre et sur mer.

A fin d'augmenter la puissance, et de reducie le poids du

S16R, une simulation des performances du moteur, le transfert

thermal et une analyse des contraintes ant 'ate' calcules. La

puissance maximale du nouveau moteur a augmenter de 120% avec des

ameliorations telles que la pression constante du systeme

suralimentation s'appliquant ou turbocompresseur recemment crees

et une revision du systerne

a

injection. Le poids du moteur a ete

reduit de 89% par rapportau moteur initial. Cela

a pu etre

realise principalement grace a l'adoption de pieces en aluminium

et de composant d'une taille precise.

La precision de ce papier porteau sur le calcul du programme

d'analyse, le systerne suralimentation le systeme

a

injection et

les resultats et champs d'observations du programme test.

INTRODUCTION

Mitsubishi S16R-S diesel engine, presented here, has been

built as a mainpropulsion engine for high-speed passenger craft

to meet the growing demand for such marine engines.

Mainpropulsion engines for high-speed boat are urged to be

light in weight and compact in size and to be high in power

output and reliability. The S16R-S is a light-weight,

high-output, high-speed version of the S16R which has been turned

out for industrial and marine applications since 1989.

This report describes the performance simulation and the

thermal load and structural analyses conducted for the

development of the S16R-S, constant pressure turbocharging, a

newly developed turbocharger adopted as a result of the

simulation and analyses, improvement of the fuel injection

system, etc.

The S16R-S is a water cooled, 4 stroke _{cycle, direct}

injection, _{16 cylinder, 60 vee type high-speed diesel engine, the}

bore 170 mm and the stroke 180 mm. It is equipped with four

turbochargers which is made by ourselves.

Table 1 shows the specifications of the S16R-S in comparison

with those of the S16R. Fig. 1 shows its cross sections.

Table.1 Specification of S16R-S 3 Model S16R-S S16R Number of Cylinders 16-60 V 16-60 V Bore X Stroke (mm)_ 170 X 180 170 X 180 Piston Displacement(X103M3) 65.3 65.3 Maximum Output 2096/2000 1765/1800 Mean Effective Pressure (MPa) 1.92 1.80

Mean Piston Speed (m/s) 12.0 10.8

PmeX Cm (MPa.m/s) 23.0 19.4 Fuel Consumption (g/kw.h) 217 217 Length (mm) 3181 3181 Width (mm) 1386 1386 Height (mm) 1923 1923 Weight (kg) 5500 6200

Air Cooler Plate Fin Type Area X1.5 Spilit Cooling System

[Piston[

ALMITE Finished Top Face

Injection Pump Change the Pre-Stroke TIN Plating Plunger Re-Matching

the Delivery Valve

Crankshaft

I

Nitriding Light weight

Fig.1 S16R-S Cross

Section

Turbocharger

'Constant Pressure Turbocharging

I

Oiljet

Made of Aluminum

High efficiency with Diffuser Re-circulate Compressor Cover 2 Nozzle oil jet Connecting Rod Uniformed face pressure Hardening of serration _{Main Cap}

I

Decreasing Hight

lOilpan,Front&Rear Gear Case.Inj.Pump

Bracket

J-COMPONENT DESIGN

In the development of the S16R-S, the calculation of

performance cycle and the analyses of thermal and mechanical

strength of the major components and lightened parts were

comprehensively made in order to shorten the development period

and improve the development efficiency.

Power output of an engine can increased by increasing either

mean effective pressure (Pme) or engine speed (Ne). In case of

the 516R-S, both Pme and Ne were increased on the basis of our idea, which it is more reliable to increase both Pme and Ne than

Pme or Ne only. The target was to increase power output of the

S16R-S by 20% than conventional S16R. In order to increase the

output of the S16R-S and secure high reliability of the S16R

series, the optimum points of Pme and Ne were determined by the

simulated calculation. Fig. 2 shows the thermal load (

theoretical ) at the rated output point. This result derived the

conclusion that it is possible to decrease the combustion chamber thermal load by 18% even if Ne is increased from 1800 rpm to 2000 rpm and Pme, from 1.80 MPa to 1.93 MPa, provided that intake air

charge pressure (Ps) is increased from 0.29 MPa to 0.36 MPa. This

is the reason why a high-efficiency, high-pressure ratio

turbocharger has been developed to be used for the S16R-S.

For supercharging , a constant pressure turbocharging

method has been adopted. Because turbocharger work in higher

efficiency on constant pressure system than on pulse pressure

system, and one cylinder exhaust pulse does not interferes with

another cylinder blow down on constant pressure turbocharging

system, if we increased the valve over lap to lower the exhaust

temperature. (Fig. 3)

The maximum cylinder pressure (Pmax) of the S16R-S remains

the same by changing its compression ratio from 14 to 13 as a

result of the cycle calculation. Hence S16R-S have retained

mechanical strength and reliability.

The valve overlap has been changed from 61 deg. to 93 deg.

to optimize the valve opening and closing timing at high speed (

2000 rev./min ).

As a result of the changes and improvements which was

outlined above, the S16R-S has successfully attained the desired goal to deliver high power output by high supercharging at high

speed, with the cylinder pressure, exhaust temperature and

specific fuel consumption maintained below those of the

conventional S16R.

Design Details

Fig. 1 shows the S16R's parts which have been changed to be

0. 26 .= O. 24 MI . 7 IL, =CY S CY TI & 0.05 7 e..I 1100 1000 800 700 -T e =630V Op S---. A1896 Ac iO3 2850P5/2000rpa n,, 0 APS/Lth,-- O. 564 -,1096 0.620 11 up 3.2 3.4 3.6 3.3 4.0

Charge Air Pressure Ps (X10-11Pa)

Fig.2 Heat Load Calculation

2.2 2. 0

240011S/1800r pro (Conventional Output)

)7 C =0.561 (PS=2. 94 a I a) 950 850 220 215 210 -700 650 GOO AT Constant Turbocharging it 0 APS/1.1h= 0.561 -0096 0.62O d up be 2.2 2.0 Compression Ratio ).: =13 Pulse Turbochargi ng A n =0.504 3.0 2.5 2.0 7.1

-00

3.2 3.4 3.6 3.8 1.0

Charge Air Pressure Ps (X10- '11Pa)

Fig.3 Comparison between Pulse Turbocharging

and Constant Turbocharging

I 500 I) is a KM SOt O[ _-5 00 z15 [;; Peal +9.596 400

---II 000 an 0.22 0.01

used for the S16R-S. For decrease in weight , S16R-S changed the

material of its oil pan, front gear case and injection pump

brackets and so on from iron to aluminum alloy, and remove excess

portion from its crankshaft and main bearing caps. For

high-output, high-speed operation, the air cooler and the oil

jets for cooling the pistons, injection pumps and turbochargers

etc. have been changed. 1. Main moving parts

The main components such as crankshaft, crankcase,

connecting rods and pistons were carefully analyzed for thermal

and mechanical stresses that would occur in increasing in power

output and engine speed and decreasing in weight. As necessary,

countermeasures were took or they were improved by redesign,

revision of the specifications. 1.1 Crankshaft

Fig. 4 shows _{typical results of the crankshaft stress}

analysis obtained by testing a solid model according to the

Finite Element Method (FEM). By using the stress concentration

coefficient determined by this method, _{the accurate values were}

able to obtained for bending and torsional _{stresses occurring in}

various parts of the crankshaft.

The crankshaft for conventional S16R is treated by induction

hardening, which cause the residual tensile stresses in the

surface layer at the crank pin fillets. The bending stress

occurring in the S16R-S's crankshaft increases about 10 % by the

20% engine speed increase. Hence the heat treatment for the

S16R-S's crankshaft was changed from induction hardening to

nitriding, which cause compressive residual stress in the surface

layer of the crank pin fillets. Thanks to this nitriding

treatment, _{the S16R-S's crankshaft has been greatly improved in}

safety factor as compared with the crankshafts of the early

models.

The steelmaking process has been controlled to prevent

reduction of crankshaft strength due to non-metallic inclusions.

Moreover, the structure was closely examined and _{a steel material}

suitable for nitriding was selected for the _crankshaft. 1.2 Connecting Rod

The connecting rod strength (reliability) was analyzed by

the FEM and component test. _{In the test, however, it was found}

that some portion of the big end joint serrations (teeth) was

insufficient in _{fatigue strength, because of increasing engine}

speed. For this reason, _{the relief depth of connecting rod bolt}

thread were increased to equalize the clamping pressure.

Moreover, the heat treatment conditions _{were changed to increase}

the hardness by % in order to improve _{the fatigue strength and}

safety factor of the big end. And the effect _{of this modification}

was confirmed by the tensile component test.

1.Analysis of Bending Stress and Torsional Stress Analysis Result of FEM Bending Principal Torsional Principal Stress Distribution Stress Distribution

2.Analysis of Fatigue Strength

00 0.5 3.0i1 Film Characteristics 2 1 Induction Hardening (Considering of Residual Stress) Nitriding f-1.7 \11 200 1.0 1 5

Torsional Stress/Fatigue Limit

1765kw/1800min-1

2096kw/2000min-1

300

Period of oil film Safety Factor below 2

Fig.4 Analysis of Crankshaft

Factor of Stress Concentration

Pin Main Bending 5.163 11.22 Twisting 1.991 3.431

Conventional Changing for

Power Up Main Bearing

li

Ill Crank Pin 0

0

1.5 -I w 0.5 100

(star)

4r

fretting Boundary Conditiont _{heasurement Result of;}

of Temperature _{(Piston Temperature}

Setting Boundary Condition

4

of Heat Transfer Coefficient(

(Analysis of Conduction' by 2Dimensional FEM

Correction of Heat Transfer Coefficient Calculation Result

Distribution of Temperature _{Distribution Heat Flux}

Heat Balance

Top land 1st Ring Groove

(Analysis of Temcerature and Stress by 3D-FEN

Estimation of Piston Strength High cycle Fatigue by Gas Pressure Heat Cycle Fatigue by Start and Stop

NC YES!

STH

Refry

Itngine.Performance Simulatorl

---?.4ecision of Boundary Conditioni

Distribution of Temp.

Fig.5 Piston estimation Flow Chart

jaata Base of Heat ti

(Transfer Coefficien Cooling Channel Distribution of Principal Stress GOOD: C Top END

1.3 Piston

As to the piston, the heat transfer was calculated by the

FEN and engine performance simulation, which predict the heat

quantity from combustion gas to the pistons, in order to

determine the piston temperature and estimate the thermal stress

and stress due to gas pressure.

Fig. 5 shows the flow chart of our piston strength

estimation. At the first, a boundary condition of piston

temperature and heat transfer coefficient were predicted from the

data base of measurement piston temperature result and heat

transfer coefficient of other engines. Next, distribution of

temperature, heat flux and heat balance of piston were analyzed

by using that boundary condition and the total heat flux which

was predicted by engine performance simulator. And this result

was compared with the result of engine performance simulator. If

the result was right, the boundary conditions were decided and

analysis was continued. If the result was not suitable, the

boundary condition of heat transfer coefficient was corrected,

and this analysis was tried again. Finally, analysis of the

temperature and stress were carried out by three dimensional FEM,

and estimated piston strength.

As a natural consequence, the combustion chamber formed of

the crown has been increased in depth to reduce the compression

ratio and the cooling channel for a jet of the cooling oil

changed in location to secure reliability. The valve overlap has

been increased to increase the amount of charge air. The

conventional S16R had a single-hole oil nozzle, which jetted the

cooled oil into the piston cooling channel only, but the 516R-S

has a 2-hole oil nozzle,which the oil being sprayed into the

cooling channel and also into the back of the piston to improve

cooling. We checked this effect by measuring the pistons

temperature. Fig. 6 shows this result and simulation analysis. It

shows that piston temperature was almost the same as conventional

Sl6R's.

Conventional 516R(1765kw/1800min ill S1611-S(2096ke/2000min

2.11

Measurement of Temperature

Fig.6 Piston, Temperature Distribution

10

225

2. Fuel injection pump

The S16R-S uses PS-type fuel injection pumps designed and

built by Mitsubishi. Table 2 shows the specifications of this

pump. There are some problems to be solved when the rated speed

and power of the engine is _{to be increased. They are maximum}

allowable working pressure of the pumping element, injection

quantity, secondary injection, cavitation and sticking of the

plungers. Hence some parts of PS pump described below was

changed.

Table 2 PS pump Specifications

The pre-stroke was changed from 5 mm to 4.5 mm to prevent

that injection pressure increase too much higher than the maximum

allowable pressure of the pump element for high _{speed and also to}

prevent that the tappet rollers got over the cams nose in

injection period because of high injection quantity.

PS pump uses a special delivery valve which _{acts as 2 stage}

retraction valve to prevent dribbling at the end of each

injection, cavitation and second injection. The conventional

delivery valve is shaped as to pull back _{predetermined amount of}

fuel at the end of injection so that neither dribbling nor

needless secondary injection would take place. _{But to match wide}

load and speed range is too difficult. Hence _{an ideal delivery}

valve was developed. It was designed _{on the basis of the concept}

which the fast retraction, would be followed by a slow

pulling

back to cushion off the primary reflection _{wave. Now, the special}

delivery valve of PS pump approximates _{the ideal one described}

above. It is shown in Fig. 7. {1}

The retraction collar is indicated as (1) and the protruding

part, as (2). In operation, the valve retracts fast for the

initial pulling back until its protruding _{part begins to enter}

the delivery valve seat. During its further entry, a slow

retraction ensures. The duration, timing and amount of pulled

back fuel in this slow retraction _{are governed by the length of}

the protruding part and its clearance in the bore of the seat. [1)

We have matched the length of the protruding part with the

clearance for high speed and high injection quantity. Fig. 8

11

Plunger Diameter _17mm

Cam Lift 15mm

Cylinder Arrangement Inline 6 or 8

Cylinder center Distance 45mm

Mean Geometric Pumping Rate _{105mm3/deg.Cam}

Max. Fuel Injection Quantity 680mm3/st.

(MPa)

Special Delivery Valve 100 Valve Seat Special _(MPa) Delivery Valve 100 . Conventional Delivery Valve 50 0 Nozzle Side g=400(mm3/st) Np-35(s-1) Pump Side Needle lift 0 10 20 30 40

Static CAN Angle (deg)

Inj Timing

Fig.7 Delivery Valve Construction

shows these result. Thus the problems of maximum allowable

working pressure of the pumping element, secondary injection and

cavitation have been solved for obtaining a target injection

quantity of 610 mm3/stroke. [2]

The plunger has been plated by TiN to prevent sticking that

tends to occur when the engine speed is increased.

The effect of these improvements was verified in the

endurance test of the injection pump component and completed

engine, and optimum pump for S16R-S was obtained. 3. Turbocharger

As a result of close examination of the engine performance,

we found that the turbocharger should be increased by 30% in

boost pressure, 35% in air flow and 3% in efficiency. This is the

reason why a new turbocharger has been developed.

The targets were to develop an impeller achieving pressure

ratio up to 4 and working in high efficiency from low to high

pressure ratio and to develop a diffuser matching with the above impeller.

Aluminum alloy impeller was considered best for reliability

and cost. The material strength restricted the maximum peripheral

speed. Hence new impeller had to achieve pressure ratio up to 4

under this peripheral speed condition.

The temperature-rise coefficient had to be improved by 3%,

so the backward angle of blades was changed from 30 deg. to 20

deg. Besides, the number of blades were increased by 20% for

improving efficiency in the high pressure ratio area by

Conventional 1.Injection Quantity 510=3/Stroke Pump Speed 900 rpm 2.Plunger without surface treatment Conventional 1.Pressure Ratio 2.9 Flow Rate 0.6m3/a 2.Turbocharger Type Compressor Without Diffuser Backward Angle of Vane 30° Turbine

Without Nozzle Ring

13 Pump Side a1 I

ct\clec

Nozzle Side ter"-°e1C-4-114) goareAA 300 400 500 600 700. Injection Crtaantity(mm3/St.)

Fig.8 Injection Pump,

0 20 i° c su OF 0 & dam 550.35z10 4--otpx/.0 O2.88x1760 4-Quantity of Retraction 170=3 ( custl 0702nd) 153mm0 t 51 1st 002 2nc1), Pre-stroke 4.5= 5mm 0 120

Changing for Power Up

0 ila 1.Injection Quantity 610mm3/Stroke _{T 100,} Pump Speed 1033 :Pm 0; 90

2.Matching the quantity and

speed of retraction 0

3.Changing the pre-stroke 41.Plunger with Tig_plating.1

44

Rated Out Put

516R-S

MN WWII MIN IMAM

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Rated Out Put

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0.2 0.4 0 5 0.8 1 0 1.20 0 2 0.4 0.6 0.8

Air Slow Rate (3/s) _{Air Flow Rate(m3/s)}

Fig.9 Turbocharger and Operating Point

Changing for Power Up

1.Pressure Ratio 3.7 Flow Rate 0.82md/s 2.Ttrbocharger Type

Compressor With Diffuser

Backward Angle of Vane 20.

Re-circulate Type Compressor Turbine

With Nozzle Ring

a

1100

1000

2500

2000

150

1000

500

Constant Turbocharging with

Recirculate Type Compressor

1000 1200 1400 1600 1800 2000 2200 Engine Speed Ne [min-1]

Fig-10 Surging Limit

sea water

Wet

Charge

Art

Air Cooler Thermostat 4 Propeller Cutout Cylinder

00000000

00000000

Pulse Turbocharging with Recirculate Type Compressor

Constant Turbocharging with Conventional Type Compressor

14

' Pulse Turbocharging with Conventional

Type Compressor

sea water PUMP

Water PumP Sea Water

Cutlet

Fig.11 Cooling System (Spilit Cooling)

0-increasing temperature-rise coefficient _{and decreasing the wall}

pressure load. And a three dimensional blades shape with _splitter

blades was adopted.

For the diffuser, the number of vanes was decreased, because

of increasing the area from surge to maximum flow.

Fig. _{9 shows a comparison between the new and conventional}

turbochargers. _{It can be easily seen that both operating range}

and efficiency of the new turbocharger _{have been much improved.}

The new compressor achieved pressure ratio 4.4 at maximum

circumferential velocity and 80% _efficiency in wide range

pressure ratio from 2 to 4.

Besides, the _{turbine of the new turbocharger is 'equipped}

with a nozzle for increasing efficiency.

For surging problem, we have adopted a recirculate-type

compressor. By this compressor cover and constant pressure

turbocharging, the _{sufficient surging limit was obtained, Fig.}

10. [3]

4- Split Cooling

The air cooler of the conventional _{S16R engine was directly}

cooled by sea water. This cooler used a fin-tube type core which weighed heavier and was likely to suffer damage by sea water than

fresh water cooled air cooler. _{Hence, the S16R-S uses a fresh}

water-cooled, split type cooling system.

Fig. 11 shows this split cooling system. In this system, the

flow of coolant from the crankcase _{is divided into two circuits,}

one leading to the heat exchanger and the _{other to the by-pass}

circuit. 1/3 of the coolant flows into the former circuit and 2/3

into the latter circuit. The hot (about 75 deg. centigrade)

coolant flowing into the heat exchanger _{is cooled down to about}

43 deg. centigrade. This low-temperature coolant flows to the air

cooler for lowering the intake air temperature to 60 degree

centigrade. Then it join the other 2/3 hot _{coolant and flows into}

engine as 70 deg. centigrade water.

Fig. 12 shows a comparison between the _{sea water-cooled type}

cooling system, and the split _{(jacket water-cooled) type cooling}

system in the temperatures of various parts of the engine

coolant. In the sea water cooling system, the coolant temperature

at the air cooler inlet is low and _{it unnecessarily lowers the}

intake air temperature under light load. Therefore the engine apt

to produce white exhaust smoke. _{In the split cooling system, the}

temperature of the _{coolant passing through the air cooler}

is

maintained rather high even under light _{load condition to prevent}

white exhaust smoke. 5. Light. Weight

Fig. 13 _{shows the process of reducing the weight of major}

component parts for the S16R-S.

About 60% of reduced weight have been _{obtained by changing}

material of parts from iron to aluminum. _{They are front and rear}

gear cases, air intake ducts, rocker cases, injection pump

brackets,' oil pan and _{so on_ The strength of these parts have,}

90 BO Et.2 70 60

-m 50 a E-40 30 20 &

:7-7-1-Cooler Outlet Air Temp.

c) Spilit Cooling

A After Cooling by Sea Water

A-72

Engine Outlet Water T my.

---Cooler Inlet Water Temp.

200 400 600 Made of Aluminum 570kg Rremove Stock 2151g Increase Delete 170kgi +255:(g1

Fig.13 Sl6R-S Reduced Weight

16

1

1 _I

20 40 60 80 100 110

Load (%)

Fig.12 Water Temperature with Spilit Cooling

Engine Weight Target 6200kg-,5500kg

800 kg 1000 Total Red-used Weight 700 kg

been closely analyzed by the FEM method and the stress

measurement were taken on the engine for verification of

reliability.

The crankshaft, camshafts, main bearing caps timing gears

,etc were reduced in weight by removing excess portion.

As a result of the above-mentioned modification for weight

reduction, the S16R-S is only 5500 kg in total weight, 18% less

the weight of the S16R which is 6200 kg, and is 3.9 kg/kW in

power-weight ratio. The S16R-S achieve a _{top-of-the-class}

lightweight engine available today.

The changed or modified parts for high power output, high

speed and lightweight _{characteristics, which described above}

amounted up to about 40% of the major component parts of S16R-S.

Performance

Fig. 14 shows a comparison of the pulse pressure

turbocharging and constant-pressure turbocharging. _{In case of the}

pulse pressure turbocharging, the exhaust pulse from one cylinder

interfered with scavenging and charging of another and the

exhaust valves action became unstable because of _{the pulse coming}

from another cylinder before the valves close.

In case of the constant pressure turbocharging, _{however, the}

pressure in the exhaust pipe is constant, about 0.18 MPa/cm2, _so

that the valves open and close stably at the _{designed timing, and}

the pulses coming from another cylinder didn't _{interferes with}

scavenging and charging.

As a result, it becomes possible to _{increase the valve}

overlap for reducing the thermal load in the _{cylinder. Fig. 15}

shows _{the performance characteristics of the constant pressure}

turbocharging with increased valve overlap.

In conclusion, the target performance _{has been obtained and}

the expected reduction of the thermal load was achieved. The

result is up to expectation; the fuel _{consumption for the rated}

output operation is 212 g/kW-hr and that for _{80% output operation}

is 200 g/kW-hr, 3 g/kW-hr less _{the fuel consumption of the}

conventional engine.

The temperature _{and stress measurements taken on the above}

mentioned major component parts were below the maximum

permissible limits. The bench endurance _{tests of the completed}

S16R-S engine had been carried out by two engines for a total of

3000 hours for verificat:on of _{reliability. The tests were the}

1000 hours continuous full load test which inclosed the test with

a marine gear at installed angle, the 3 minute idle and rated

load cycling test and the test of _{the simulated load pattern.}

Fig. _{16 shows performance of 1000 hour endurance test. After the}

test, the engine was disassembled and _{measured worn quantity of}

the parts to estimate the routine service _{and overhaul intervals.}

Judging from these measurements, the same intervals were

expected, notwithstanding the _{power output has been increased by}

120%.

4 3 2 0 180 360 540 720 Crank Angle (tim) 3000 4 3 2500 2 Overload power 2300kw 2060r/min 0 0 Max.cont.power 2100kw 2000r/min 2000 3.< LU 5=

Intake air temp.25t

1500

Raw wate temp.25t

Propeller curve CO CC 7 7,1 UJ C) C-3 1000 Fuel consumption curve 2 43 7 'f5C) 0 500 0 1000 1200 1600 1600 1000 2000 2200 0 ILESO 360 540

Crank Angle (deg.)

ENGINE SPEED

(r/min)

Fig.14 Exhaust Pressure

Pig. 15 S16R-S Engine Performance Map

0

0

0 CC) 100 50 0 0 Cf.) Inclined Configuration

r

Exhaust Gas Temp.

CD

Legend

1.Engine S16R-S

2.Torsionally resilient 3.Reduction gear box

4.Coupling with flexing

5.Reduction gear box 6.Engine S16R-S

7.Torsionally resilient

19

Smoke

Be

°japan Oil Temp.

Charge Air Temp.

Intake Air Temp.

200 400 600 800

Endurance Period (hours) Fig.16 Endurance Test

1000

irliiwitik atgingp

fg=3E4=4.2.Dk

r..., mb.tx-a rubber coupling element rubber coupling x E.::.

F1g.17 Fast Liner Installation of 4 XS16R-S

u 700

ro 600

0

Field Test Program

This engine will be installed on a water jet-propelled,

350-passenger high-speed craft capable of cruising at 40 knots

service speed as a main engine for driving the 2-shaft 2 water

jets. This craft is due to sail on a sea trial since August,

1992, and she is is supposed to enter service for April, 1993.

Fig. 17 shows the configuration of the engine and marine gear on

this craft.

CONCLUSION

The theoretical and experimental analysis has confirmed that

S16R-S has been able to increase the out put and engine speed and

decreasing the engine weight from conventional S16R.

The new high efficiency turbocharger and improved high

pressure injection pump for S16R-S enabled the new engine to

realize the way shown by the analysis. The constant pressure

turbocharging supported to decrease heat load in the cylinders.

The result of enduarance test carried out on the two

prototype engines have shown that the over hall period of the new

engine are the same as conventional engine as well as heat load

and mecanical load.

REFERENCES.

[rI] Tsuneo HARADA, Motoi KAWASHIMA, Ichiro ICHIHASHI

"Development of New High-Speed Diesel Engine Series with High-Pressure In-Line Fuel Injection Pumps"

CIMAC 1991

[2] Tatuso TAKAISHI, Mataji TATEISHI, Etsuo KUNIMOTO,

Tashika MATSUO, Yoshinori NAGAE, Hiroshi OIKAWA

"Prediction of Cavitation Erosion in Diesel Engine Fuel Injection Systems"

SAE Paper No. 871631 [3) F.B. FISHER

"Application of Map Width Enhancement Devices to Turbocharger Compressor Stages"

SAE Paper No. 880794