Xin Q. Diesel Engine System Design

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388 Diesel engine system design

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SAE paper 2000-01-3545.

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Engineers, Stevenage.

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prediction’, SAE paper 2000-01-1266.

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powertrain component efciencies for a light-duty vehicle with a CVT operating over

a driving cycle’, SAE paper 2003-01-3202.

Diesel-Xin-05.indd 388 5/5/11 11:49:27 AM

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389Engine–vehicle matching in diesel powertrain system design

Montazeri-Gh M, Varasteh H and Naghizadeh M (2005), ‘Driving cycle simulation for

heavy duty engine emission evaluation and testing’, SAE paper 2005-01-3796.

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simulation and control’, SAE paper 1999-01-0907.

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system modeling methodologies: philosophy and implementation’, SAE paper

971089.

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on evaluation method and improvement of shift quality of automatic transmission’,

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paper 2001-01-3452.

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for advanced vehicle powertrains’, SAE paper 2006-01-0665.

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for reduced fuel consumption: a review of the technical content in the 2002 national

research council report on CAFÉ’, SAE paper 2002-01-0628.

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970408.

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900619.

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transient drive cycles using CRUISE-BOOST co-simulation techniques’, SAE paper

2002-01-0627.

SAE Surface Vehicle Information Report J2084 (1993), ‘Aerodynamic testing of road

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SAE Surface Vehicle Information Report J2071 (1994), ‘Aerodynamic testing of road

vehicles – open throat wind tunnel adjustment’.

SAE Surface Vehicle Information Report J1087 (2000), ‘One-way clutches – nomenclature

and terminology’.

SAE Surface Vehicle Information Report J2408 (2002), ‘Clutch requirements for high-

torque truck and bus engines’.

SAE Surface Vehicle Information Report J1270 (2006), ‘Measurement of passenger car,

light truck, and highway truck and bus tire rolling resistance’.

SAE Surface Vehicle Information Report J1715 (2008), ‘(R) Hybrid electric vehicle

(HEV) & electric vehicle (EV) terminology’.

SAE Surface Vehicle Recommended Practice J1252 (1981), ‘SAE wind tunnel test

procedure for trucks and buses’.

SAE Surface Vehicle Recommended Practice J1321 (1986), ‘Joint TMC/SAE fuel

consumption test procedure – type II’.

SAE Surface Vehicle Recommended Practice J1526 (1987), ‘Joint TMC/SAE fuel

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Diesel-Xin-05.indd 389 5/5/11 11:49:27 AM

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390 Diesel engine system design

SAE Surface Vehicle Recommended Practice J678 (1988), ‘Speedometers and tachometers

– automotive’.

SAE Surface Vehicle Recommended Practice J2177 (1992), ‘Chassis dynamometer test

procedure – heavy-duty road vehicles’.

SAE Surface Vehicle Recommended Practice J1594 (1994), ‘Vehicle aerodynamics

terminology’.

SAE Surface Vehicle Recommended Practice J2264 (1995), ‘Chassis dynamometer

simulation of road load using coastdown techniques’.

SAE Surface Vehicle Recommended Practice J1667 (1996), ‘Snap-acceleration smoke

test procedure for heavy-duty diesel powered vehicles’.

SAE Surface Vehicle Recommended Practice J647 (1997), ‘(R) Transmissions – schematic

diagrams’.

SAE Surface Vehicle Recommended Practice J1711 (1999), ‘Recommended practice for

measuring the exhaust emissions and fuel economy of hybrid-electric vehicles’.

SAE Surface Vehicle Recommended Practice J2452 (1999), ‘Stepwise coastdown

methodology for measuring tire rolling resistance’.

SAE Surface Vehicle Recommended Practice J2453 (1999), ‘Manual transmission and

transaxle efciency and parasitic loss measurement’.

SAE Surface Vehicle Recommended Practice J649 (2000), ‘Automatic transmission

functions – terminology’.

SAE Surface Vehicle Recommended Practice J1540 (2000), ‘Manual transmission

efciency and parasitic loss measurement’.

SAE Surface Vehicle Recommended Practice J1618 (2000), ‘Continuously variable

transmission test code for passenger cars’.

SAE Surface Vehicle Recommended Practice J923 (2001), ‘Nomenclature and terminology

for truck and bus drive axles’.

SAE Surface Vehicle Recommended Practice J1266 (2001), ‘Axle efciency test

procedure’.

SAE Surface Vehicle Recommended Practice J1608 (2001), ‘Manual transmission shift

patterns’.

SAE Surface Vehicle Recommended Practice J2548 (2001), ‘Test method to obtain lug-

up torque data for heavy-duty truck and bus engines’.

SAE Surface Vehicle Recommended Practice J2711 (2002), ‘Recommended practice for

measuring fuel economy and emissions of hybrid-electric and conventional heavy-

duty vehicles’.

SAE Surface Vehicle Recommended Practice J2188 (2003), ‘Commercial truck and bus

SAE recommended procedure for vehicle performance prediction and charting’.

SAE Surface Vehicle Recommended Practice J651 (2005), ‘Passenger car and light truck

automatic transmission and automatic transaxle test code’.

SAE Surface Vehicle Recommended Practice J1269 (2006), ‘Rolling resistance measurement

procedure for passenger car, light truck, and highway truck and bus tires’.

SAE Surface Vehicle Recommended Practice J1491 (2006), ‘(R) Vehicle acceleration

measurement’.

SAE Surface Vehicle Recommended Practice J915 (2007), ‘Automatic transmissions –

manual control sequence’.

SAE Surface Vehicle Recommended Practice J670 (2008), ‘(R) Vehicle dynamics

terminology’.

SAE Surface Vehicle Recommended Practice J2263 (2008), ‘Road load measurement

using onboard anemometry and coastdown techniques’.

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391Engine–vehicle matching in diesel powertrain system design

SAE Surface Vehicle Recommended Practice J2807 (2008), ‘Performance requirements for

determining tow-vehicle gross combination weight rating and trailer weight rating’.

SAE Surface Vehicle Recommended Practice J645 (2009), ‘(R) Automotive transmission

terminology’.

SAE Surface Vehicle Recommended Practice J1263 (2009), ‘Road load measurement

and dynamometer simulation using coastdown techniques’.

SAE Surface Vehicle Standard J1544 (1988), ‘Revolutions per mile and static loaded

radius for off-road tires’.

SAE Surface Vehicle Standard J2469 (2004), ‘Clutch application powertrain startability

rating requirements for truck and bus applications’.

SAE Surface Vehicle Standard J1082 (2008), ‘Fuel economy measurement road test

procedure’.

Sahraeian A, Shahbakhti M, Aslani A R, Jazayeri S A, Azadi S and Shamekhi A H

(2004), ‘Longitudinal vehicle dynamics modeling on the basis of engine modeling’,

SAE paper 2004-01-1620.

Schoeggl P, Ramschak E and Bogner E (2001), ‘On-board optimization of driveability

character depending on driver style by using a new closed loop approach’, SAE paper

2001-01-0556.

Shannon J V (1991), ‘The truck as a system: where are we, and where are we going?’,

SAE paper 912685.

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paper C498/34/135/95.

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for lightweight passenger cars’, Proc. IMechE, Part D: Journal of Automobile

Engineering, Vol. 215, pp. 259–271.

Sovran G and Blaser D (2003), ‘A contribution to understanding automotive fuel economy

and its limits’, SAE paper 2003-01-2070.

Steinberg P and Goblau D (2004), ‘Fuel Consumption’, in Basshuysen R and Schafer F

(eds), Internal Combustion Engine Handbook, SAE International, Warrendale, PA,

pp. 737–751.

Sutton T, Pope R, Brandewie K and Henry J (2001), ‘International truck and engine high

performance vehicle driveability – ride and handling’, SAE paper 2001-01-2787.

Thring R H (1981), ‘Engine transmission matching’, SAE paper 810446.

Vandenplas B, Gotoh K and Dutre S (2003), ‘Predictive analysis for engine/driveline

torsional vibration in vehicle conditions using large scale multi body model’, SAE

paper 2003-01-1726.

Walker M and Ford R (2000), ‘Hardware-in-the-loop, dynamometer based driver and

vehicle simulator’, SAE paper 2000-01-0289.

Watson H C (1995), ‘Effects of a wide range of drive cycles on the emissions from

vehicles of three levels of technology’, SAE paper 950221.

Wehrwein D and Mourelatos Z P (2005), ‘Modeling and optimization of vehicle drivetrain

dynamic performance considering uncertainty’, SAE paper 2005-01-2371.

Wong J Y (1993), Theory of Ground vehicles, 2nd edn, John Wiley & Sons, New

York.

Wong L T and Clemens W J (1979), ‘Powertrain matching for better fuel economy’,

SAE paper 790045.

Yonekawa T, Okada A, Ehara M and Ogasawara T (1984), ‘Analysis of driveability on

diesel vehicles’, SAE paper 840257.

Diesel-Xin-05.indd 391 5/5/11 11:49:27 AM

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392 Diesel engine system design

5.6.2 References and bibliography on electric hybrid

powertrain

An F and Santini D (2003), ‘Assessing tank-to-wheel efciencies of advanced technology

vehicles’, SAE paper 2003-01-0412.

Anderson C and Pettit E (1995), ‘The effects of APU characteristics on the design of

hybrid control strategies for hybrid electric vehicles’, SAE paper 950493.

Anderson S R, Lamberson D M, Blohm T J and Turner W (2005), ‘Hybrid route vehicle

fuel economy’, SAE paper 2005-01-1164.

Atkins M J and Koch C R (2003), ‘A well-to-wheel comparison of several powertrain

technologies’, SAE paper 2003-01-0081.

Boesel J, Romeo S and Brotherton T (2003), ‘Advanced fuels and technology forecasts

for heavy-duty vehicles’, SAE paper 2003-01-3404.

Burke A (2003), ‘Saving petroleum with cost-effective hybrids’, SAE paper 2003-01-

3279.

Chen W, Chen H, Zhang Y and Qin G (2009), ‘Modeling and optimization of vehicle

acceleration and fuel economy performance with uncertainty based on Modelica’,

SAE paper 2009-01-0232.

Chu L and Wang Q (2001), ‘Energy management strategy and parametric design for

hybrid electric transit bus’, SAE paper 2001-01-2748.

Cuddy M R and Wipke K B (1997), ‘Analysis of the fuel economy benet of drivetrain

hybridization’, SAE paper 970289.

Dembski N, Guezennec Y and Soliman A (2002), ‘Analysis and experimental renement

of real-world driving cycles’, SAE paper 2002-01-0069.

Ehsani M, Gao Y, Gay S E and Emadi A (2005), Modern Electric, Hybrid Electric,

and Fuel Cell vehicles – Fundamentals, Theory and Design, CRC Press LLC, Boca

Raton, FL.

Gonder J and Markel T (2007), ‘Energy management strategies for plug-in hybrid electric

vehicles’, SAE paper 2007-01-0290.

Inman S B, Haworth D C and El-Gindy M (2002), ‘Integration of WAVE and ADVISOR

simulations for optimization of a hybrid electric sport utility vehicle’, SAE paper

2002-01-2856.

Juda Z (2001), ‘Simulation of energy conversion in advanced automotive vehicles’, SAE

paper 2001-01-3341.

Kasseris E P and Heywood J B (2007), ‘Comparative analysis of automotive powertrain

choices for the next 25 years’, SAE paper 2007-01-1605.

Kiuchi T, Ogata M, Iizawa M, Yanase T, Susuki Y, Takeda N and Kumagai N (2001),

‘A report on advantage of a heavy-duty hybrid electric vehicle’, SAE paper 2001-

01-2777.

Kwon J, Kim J, Fallas E, Pagerit S and Rousseau A (2008), ‘Impact of drive cycles on

PHEV component requirements’, SAE paper 2008-01-1337.

Lindenkamp N, Stöber-Schmidt C-P and Eilts P (2009), ‘Strategies for reducing NO

and particulate matter emissions in diesel hybrid electric vehicles’, SAE paper 2009-

01-1305.

Louckes T (2002), ‘The opportunity for IC engines in a hybrid world’, SAE paper

2002-01-1910.

Louis J J J (2001), ‘Well-to-wheel energy use and greenhouse gas emissions for various

vehicle technologies’, SAE paper 2001-01-1343.

Miller J (2004), Propulsion Systems for Hybrid vehicles, The Institution of Electrical

Engineers, Stevenage.

Diesel-Xin-05.indd 392 5/5/11 11:49:27 AM

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393Engine–vehicle matching in diesel powertrain system design

Moon P, Burnham A and Wang M (2006), ‘Vehicle-cycle energy and emission effects

of conventional and advanced vehicles’, SAE paper 2006-01-0375.

Morita K, Shimamura K, Sugiyama G, Hori M, Itai Y, Sekiyama S, Motooka A, Sasaki

M and Suenaga K (2005), ‘R&D and analysis of energy consumption improvement

factor for advanced clean energy HEVs’, SAE paper 2005-01-3828.

Olikara C, Steiber J and Shahed S M (1995), ‘Analysis of a hybrid powertrain for heavy

duty trucks’, SAE paper 952585.

Petris C D, Giglio V and Police G (1993), ‘Can hybrid vehicles reduce the pollutant

emission in urban environments?’, SAE paper 930046.

Plassat G (2004), ‘Pollutants emissions, global warming potential effect, rst comparison

using external costs on urban buses’, SAE paper 2004-01-2015.

Poeti L, Marco J and Vaughan N D (2009), ‘Object oriented plant models for HEV

controller development’, SAE paper 2009-01-0148.

Pritchard E and Johnson R R (2005), ‘Hybrid electric school bus technical feasibility’,

SAE paper 2005-01-3615.

Rizoulis D, Burl J and Beard J (2001), ‘Control strategies for a series-parallel hybrid

electric vehicle’, SAE paper 2001-01-1354.

Rousseau A, Pagerit S, Monnet G and Feng A (2001), ‘The new PNGV system analysis

toolkit PSAT V4.1 – evolution and improvement’, SAE paper 2001-01-2536.

SAE Surface Vehicle Recommended Practice J1711 (1999), ‘Recommended practice for

measuring the exhaust emissions and fuel economy of hybrid-electric vehicles’.

SAE Surface Vehicle Recommended Practice J2711 (2002), ‘Recommended practice for

measuring fuel economy and emissions of hybrid-electric and conventional heavy-

duty vehicles’.

Takada Y, Ueki S and Saito A (2004), ‘Study on fuel economy and NO

emissions of

medium duty hybrid truck in real trafc conditions’, SAE paper 2004-01-1086.

Walters J, Husted H and Rajashekara K (2001), ‘Comparative study of hybrid powertrain

strategies’, SAE paper 2001-01-2501.

Wang W, Wang Q and Zeng X (2009), ‘Automated manual transmission shift strategy

for parallel hybrid electric vehicle’, SAE paper 2009-01-0144.

Williamson S S, Emadi A and Dewan A (2005), ‘Effects of varying driving schedules on

the drive train efciency and performance characteristics of a parallel diesel-hybrid

bus’, SAE paper 2005-01-3477.

Zeng X, Wang Q, Wang W and Chu L (2005), ‘Analysis and simulation of conventional

transit bus energy loss and hybrid transit bus energy saving’, SAE paper 2005-01-

1173.

5.6.3 References and bibliography on hydraulic hybrid

powertrain

Barr A and Veshagh A (2008), ‘Fuel economy and performance comparison of alternative

mechanical hybrid powertrain congurations’, SAE paper 2008-01-0083.

Baseley S, Ehret C, Greif E and Kliffken M G (2007), ‘Hydraulic hybrid systems for

commercial vehicles’, SAE paper 2007-01-4150.

Ivani Ž (2007), ‘Data collection and development of New York city refuse truck duty

cycle’, SAE paper 2007-01-4118.

Jackey R A, Smith P and Bloxham S (2005), ‘Physical system model of a hydraulic energy

storage device for hybrid powertrain applications’, SAE paper 2005-01-0810.

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394 Diesel engine system design

Johri R and Filipi Z (2009), ‘Low-cost pathway to ultra efcient city car: series hydraulic

hybrid system with optimized supervisory control’, SAE paper 2009-24-0065.

Kim Y J and Filipi Z (2007a), ‘Series hydraulic hybrid propulsion for a light truck –

optimizing the thermostatic power management’, SAE paper 2007-24-0080.

Kim Y J and Filipi Z (2007b), ‘Simulation study of a series hydraulic hybrid propulsion

system for a light truck’, SAE paper 2007-01-4151.

Kokkolaras M, Mourelatos Z, Louca L, Filipi Z, Delagrammatikas G, Stefanopoulou A,

Papalambros P and Assanis D (2005), ‘Design under uncertainty and assessment of

performance reliability of a dual-use medium truck with hydraulic-hybrid powertrain

and fuel cell auxiliary power unit’, SAE paper 2005-01-1396.

Nakazawa N, Kono Y, Takao E and Takeda N (1987), ‘Development of a braking energy

regeneration system for city buses’, SAE paper 872265.

Surampudi B, Nedungadi A, Ostrowski G, Montemayor A and Gruenewald H (2009),

‘Design and control considerations for a series heavy duty hybrid hydraulic vehicle’,

SAE paper 2009-01-2717.

Van Batavia B L (2009), ‘Hydraulic hybrid vehicle energy management system’, SAE

paper 2009-01-2834.

Weber T R (1988), ‘Analysis of unconventional powertrain systems’, SAE paper

885023.

5.6.4 References on pneumatic hybrid powertrain

Trajkovic S, Tunestal P and Johansson B (2008), ‘Investigation of different valve geometries

and valve timing strategies and their effect on regenerative efciency for a pneumatic

hybrid with variable valve actuation’, SAE paper 2008-01-1715.

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395

Engine brake performance in diesel engine

system design

Abstract: This chapter provides a comprehensive theory on engine

brake performance. It rst discusses vehicle braking requirement and the

impact on engine–vehicle matching in engine brake operation, followed

by a comparison between engine brakes and drivetrain retarders. It

then introduces drivetrain retarders in detail including their torque and

cooling characteristics. The performance characteristics of exhaust brakes

and compression brakes are elaborated including their mechanisms and

the interactions with valvetrain, variable valve actuation (VVA) and

turbocharger. The principles of engine brake design are introduced through

comprehensive simulation analysis on engine thermodynamic cycles in

braking operation. A braking gas recirculation (BGR) theory is developed.

Key words: retarder, engine brake, exhaust brake, compression-release

brake, retarder energy conversion ratio, retarding process efciency, braking

gas recirculation (BGR), engine brake noise.

6.1 Engine–vehicle powertrain matching in engine

braking operation

Engine brake performance analysis is an integral part of diesel engine

system design for two reasons. First, the topics of engine brake performance

are focused mainly on power, gas pressure, temperature, and ow rate.

Therefore, the theoretical foundation of engine braking is based directly

on engine thermodynamic cycle analysis. Second, the design decision of

engine brake affects air system sizing and controls. This chapter presents

a comprehensive coverage of the vehicle braking requirements, drivetrain

retarder and engine brake technologies, and analytical design for braking

performance. Both fundamental principles and parametric sensitivity analysis

of the engine brakes are presented. The parametric simulations include the

effects of braking valve lift, valve timing, valve ow characteristics and

turbocharging. The inuence of engine braking on valvetrain dynamics is

also included. Moreover, braking efciency, heat rejection, braking noise,

and high altitude operation are also discussed.

Diesel-Xin-06.indd 395 5/5/11 11:50:24 AM

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396 Diesel engine system design

6.1.1 Vehicle braking requirement and the need for

retarders

Vehicle force balance in braking

In order to analyze the braking force requirement for vehicle braking

(retarding, no fuel), a lumped model of vehicle longitudinal dynamics is

derived as follows based on vehicle force balance:

tir

Er,Er

[

tir

[

tir

[

tir

[

(

FF( FF

(

FF( FF

FF+ FF

)

(

FF( FF

(

FF( FF

FF+ FF

)

]

+FF +

)FF )

)

+FF +

)FF )

)

cdfgcd

)

– Fm –

6.1

where J

E,r

is the engine retarding torque acting on the crankshaft (including

the engine motoring torque), F

is the resistance force of drivetrain retarders,

and F

is the force of the service brakes (also called foundation brakes

or wheel brakes) applied on the vehicle wheels. Those three terms are the

retarding forces beyond the natural retarding capability of the vehicle. The

forces in the second parentheses in equation 6.1 are the natural retarding

forces of the vehicle. They are: F

, the tire–road rolling friction force; F

the aerodynamic resistance force; F

acc

, the vehicle accessory resistance force;

and F

, the drivetrain friction force. F

is the longitudinal gravity force on a

grade, and – xm

is the vehicle inertia force. The a

is vehicle acceleration,

is the total vehicle mass, and x is the rotational mass coef cient. Other

parameters in equation 6.1 are introduced in equation 5.1 in Section 5.1.2.

The need for retarding

When the vehicle needs to be propelled to overcome all resistance forces,

it needs the engine to provide  ring power. When the vehicle needs to be

stopped, it needs the service brakes to slow it down and eventually bring

it to a complete stop. When a heavy vehicle travels at a constant speed on

a downhill grade, it needs a retarder to balance the gravity force to secure

safe driving by reducing the use of the service brakes in order to prevent

brake fade. Fast deceleration and high-speed downhill operation are equally

important as fast acceleration and uphill driving performance in engine and

vehicle design. In mountainous regions, when slowly crawling downhill

is not a preferred option, the retarder is almost as equally important to a

vehicle as the  ring engine for motion control. The retarding device (or

called ‘retarders’ in general here) can be a drivetrain retarder or an engine

brake. In diesel engine system design, it is always desirable to design the

engine as a two-way power conversion device (i.e., power producing and

power absorbing or retarding) to possess the retarding function as much

as possible. If the engine can be used to replace the driveline retarder, the

overall cost of the vehicle can be reduced. It should be noted that although

Diesel-Xin-06.indd 396 5/5/11 11:50:24 AM

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397Engine brake performance in diesel engine system design

a retarding device can supplement or temporarily substitute for the service

brakes, the device should be used for downhill driving or vehicle-slowing

on level ground, rather than used as a vehicle stopping device.

The design efforts for continuous vehicle fuel economy improvement

have resulted in large reductions in the natural retarding power of the

vehicle over the past years. For example, radial tires are used to replace

the conventional bias tires to reduce rolling resistance. The reduction of

other drivetrain frictional losses (e.g., wheel bearing losses, drive axle gear

churning) also reduces the natural retarding capability of the vehicle. Air

deectors are used to reduce aerodynamic drag. Fan clutches are used to

reduce cooling fan power. Smaller displacement (engine downsizing) with

enhanced turbocharging, reduced rated speed, and decreased parasitic losses

all result in a decrease in engine friction and motoring power. As indicated

by Meistrick (1992), as a result of the increase in vehicle legal gross weight

and the reduction of vehicle natural retarding power since the 1970s, a US

Class-8 highway truck in the 1990s required an additional 110 kW (148 hp)

to maintain a downhill control speed of 62.5 mph on a 4% grade. On the

other hand, engine ring power is mainly sized for the requirements of fast

acceleration and high-speed uphill driving. Vehicle operation in mountainous

terrains often requires the use of high-ring-power engines. The contrast

between the ever increasing ring power and the gradually decreasing vehicle

natural retarding power reects an increasing mismatch between the uphill

and the downhill driving, i.e., the ratio between the uphill and the downhill

speeds becomes more and more unfavorable for heavy vehicles without

additional retarding devices. In engine system design the engine retarding

power should be increased in order to minimize the gap compared to the

disproportionally increased ring power.

High-speed downhill driving is important for trucking economy. If there

are no retarders the heavy vehicle has to move very slowly downhill to

ensure the vehicle can be stopped as needed at any moment. Higher vehicle

downhill speeds add more burdens on the service brakes, whose design is

largely limited by the brake cooling capacity. There is an increasing need to

use retarders to maintain a high control speed downhill. The control speed

is the constant vehicle speed at which the gravity force pushing the vehicle

forward on a downgrade is equal to the total of the resistance forces holding

it back without using the service brakes. The ideal vehicle operation is to

drive downhill and uphill with at least the same speed with a safety reserve

available.

Vehicle retarding is mainly an issue for heavy vehicles. The vehicle

potential energy and kinetic energy are proportional to the vehicle weight.

To control the speed of the vehicle, the available braking force per unit of

vehicle weight needs to be examined. The need for retarders results from

insufcient natural retarding capability and service brake capability on a

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