143

APPENDIX 1

SPECIFICATION OF THE TEST ENGINE

Make and model : Kirloskar, AV-1 make

General Details : Four stroke, Compression ignition, Constant

Speed, vertical, water cooled, direct

injection.

Number of cylinders : one

Bore : 80 mm

Stroke : 110 mm

Swept volume : 553 cc

Clearance volume : 36.87 cc

Compression ratio : 16.5 : 1

Rated output : 3.67 kW at 1500 rpm

Rated speed : 1500 rpm

Injection pressure : 200 bar

Fuel injection timing : 23 deg CA BTDC

Type of combustion chamber : Hemispherical open combustion chamber

Fuel : High Speed diesel

Lubricating oil : SAE 40

Connecting rod length : 235 mm

Valve diameter : 33.7 mm

Maximum valve lift : 10.2 mm

144

APPENDIX 2

ELECTRICAL DYNAMOMETER

Make and Model : Laurence Scott and electromotor Ltd.,

Norwich and Manchester, UK

Volts : 220/230

Maximum power : 10 kW

Windings : Shunt

Rated current : 43.5 A

RPM : 1500

Rating type : Continuous

Machine No. : 103320

APPENDIX 3

EXHAUST GAS ANALYSERAutomotive exhaust gas analyzer Model QRO 402

Make: QROTECH CO LTD., Korea

Measuring item Measuring method Measuring range Resolution

CO (%) NDIR 0.00 - 9.99 0.01

HC(ppm) NDIR 0 - 15000 1

CO2(%) NDIR 0.0 - 20.0 0.01

NOx(ppm) Electrochemical 0 - 5000 1

145

APPENDIX 4

SMOKE METER

Type and make : TI diesel tune, 114 smoke density tester TI

Transervice

Piston displacement : 330 cc

Stabilisation time : 2 minutes

Range : 0 – 10 Bosch smoke number

Minimum time period : 30 sec

Calibrated reading : 5.0 ± 0.2

APPENDIX 5

PRESSURE TRANSDUCER

Model : KISTLER, Switzerland.

601 A, water cooled.

Range : 0 to 250 bar

Sensitivity : -14.80 pC/ bar

Linearity : 0.1 < ± % FSO

Acceleration sensitivity : <0.001 bar/g

Operating temperature range : -196 to 200 0 C

Capacitance : 5 pF

Weight : 1.7 g

Connector, Teflon insulator : M4 x 0.35

146

APPENDIX 6

CATHODE RAY OSCILLOSCOPE

Make : Hewlett Packard, HP54600B SERIES

Channels : 2 Nos.

Range : 2 mV/div to 5V/div

Accuracy : ±1.5%

Verniers : finely calibrated

Band width limit : 20 MHZ

Trigger System

dC to 100 MHZ 1 div or 10 m V

Modes : Auto

Hold off : Adjustable from 200 ns to 135

External Trigger

Range : ±18V

Sensitivity : dc to 100 MHZ 100mV

Input resistance : 1 M

Input capacitance : 13 pf

Display System

7 inch raster CRT

Resolution 255 vertical by 500 horizontal points

147

Acquisition System

Maximum sample rate : 20 MSa/s

Resolution : 8 bits

Advanced Functions

Voltage : Varg, Vrms, Vp-p, Vtop, Vbase, Vmin, Vmax

Time : Frequency, period, +width, -width, duty cycle, rise

time and fall time

Cursor : manual or automatic

Autoscale : Vertical / Horizontal

Power : Line Voltage 100 Vac to 240 Vac

Line Voltage selection-Automatic

Line Voltage frequency-45 HZ to 440 HZ

Maximum power : 220VAConsumption

General

Humidity : 95% Rh +40°C

Temperature : -10°C to 55°C

MIL-T-28800D for type III, class 3, style D

EMI

MIL-T- FTZ 1046 Class B

Vibration : 15 min along each of 3 xy axis

Displacement, 10 HZ to 55 HZ in one man cycle

Weight : 6.2 Kg.

148

APPENDIX 7

CHARGE AMPLIFIER

Make : KISTLER Instruments

AG, Switzerland

Measuring ranges : 12 stages graded

pC ±10…500’000

1:2:5 and stepless 1 to 10

Transducer sensitivity, 5 decades : (*) pC/M.U. 0,1…11’000

Continuously adjustable between

Accuracy

Of two most sensitive ranges % <± 3

Of other range stages % <±1

Linearity of Transducer Sensitivity % <±0,5

Potentiometer adjustment

Calibration capacitor pF 1’000±0,5

Calibration input, sensitivity pC/mV 1±0,5

Input Voltage, maximum with pulses V ±125

Widths < 0, 3 s

Linearity (**) %FSO <±0,05

Frequency response error with standard

Filter 180 kHz at 50 kHz % -1…+3

at 100 kHz % <±5

3-dB-frequency with standard filter kHz 180±10%

180 kHz, input capacitance up to 200 pF

Time constant resistor setting Long, about 1014

setting Medium, about 1011

setting Short 109

Time constant, = Rg Cg setting Long s >1’000…>100’000

149

setting Medium s 1 …5’000

setting Short s 0’01…50

Voltage output, unlimited short circuit proof

Full scale output (**) V ±10

Output current mA ±5

Output impendance 100±5%

Open circuit saturation voltage V >±12..< ±15

Cable noise signal, due to input capacitance pCrms/pF <3 10-5

Hum and noise, input shielded (***) mVrms <0,3/<2

Zero offset during reset, over 10 hrs. (***) mV <±1 / <±5

Zero error, during reset, due to supply

Voltage variations±20% (***) mV <±1 / <±10

Thermal zero shift, during reset

Due to temperature changes (***) mV/°C <±0,5 / <±5

Drift, due to leakage current of input pC/s <±0,03

MOSFET, at 20°C

Adjustment range for zero offset, input stage mV ±200

Output stage mV ±250

(*) M.U. = mechanical unit, e.g. Bar, N, g.

(**) FSO = full scale output

(***) Dial for transducer sensitivity adjustment set to 10-00 resp. 1-00

150

APPENDIX 8

ELECTRONIC BALANCE

Make : SHIMADZU, Japan

Model : AY62

Weighing capacity : 62 g

Minimum display : 0.1 mg

Standard deviation ( ) : mg

Linearity : ± 0.2 mg

External weight value for : 60 g

Calibration

Pan diameter : Ø 80 mm

Stability of sensitivity : ± 2 ppm / °C

(10°C to 30°C)

Operating temperature : ± 5 to 40°C

Range

Power supply : Input 100 – 250 VAC

APPENDIX 9

TACHOMETERMake : FUJI, Japan

Type : MECHANICAL

Range : 0 – 10,000 rpm

Resolution : 20 rpm

151

APPENDIX 10

HOT AIR OVEN

Name : SRICO electric hot air oven with digital temperature

Controller

Power supply : 220 V, 50 Hz.

Temperature range : 50 – 250 C

Accuracy : 1 C

Mode of control : Auto-digital controller

Mode of heating : Imported BDG 80 / 20 nickel wire

152

APPENDIX 11

ERROR AND UNCERTAINTY ANALYSIS

Error is associated with various primary experimental measurements and

the calculations of performance parameters. Errors and uncertainties in the

experiments can arise from instrument selection, condition, calibration,

environment, observation, reading and test planning. Uncertainty analysis is

needed to prove the accuracy of the experiments. The percentage uncertainties

of various parameters like load and brake thermal efficiency were calculated

using the percentage uncertainties of various instruments given in Table 3.2.

An uncertainly analysis was performed using the equation

Total percentage uncertainty

= Square root of{(uncertainty of TFC)2 +(uncertainty of load)2 +

(uncertainty of brake thermal efficiency)2 + (uncertainty of CO)2 + (uncertainty

of unburned HC)2 + (uncertainty of NOx)2 + (uncertainty of smoke number)2 +

(uncertainty of exhaust gas temperature)2 + (uncertainty of pressure pickup)2}

= square root of {(1) 2 + (0.2) 2 + (1) 2+ (0.2) 2+ (0.2) 2 + (0.2) 2+ (1) 2+

(0.15) 2+ (1)2}

= ± 2.28 %

153

The errors associated with various measurements and in calculations of

performance parameters are computed in this section. The maximum possible

errors in various measured parameters namely temperature, pressure, exhaust

gas emissions, time and speed estimated from the minimum values of output

and accuracy of the instrument are calculated using this method. This method is

based on careful specification of the uncertainties in the various experimental

measurements.

If an estimated quantity, R depends on independent variable like(x1, x2, x3…….

xn) then the error in the value of “R” is given by

R = f (x1, x2, ................... xn) (A 11.1)

with `R’ as the computed result function of the independent measured variables

x1, x2, x3, ..................... xn, as per the relation.

x1, ± x1, x2 ± x2, ......................., xa ± xa

as the error limits for the measured variables or parameters

and the error limits for the computed result as R ± R

To get the realistic error limits for the computed result, the principle of

root-mean square method was used to get the magnitude of error given by

Holman 1973

2/122

22

2

11

.................. nn

xxRx

xRx

xRR

(A11.2)

Using equation A11.2 the uncertainty in the computed values such as

load, brake thermal efficiency and fuel flow measurements were estimated. The

154

measured values such as speed, fuel time, voltage and current were estimated

from their respective uncertainties based on the Gaussian distribution. The

uncertainties in the measured parameters, voltage ( V) and current ( I),

estimated by the Gaussian method, are ± 3 V and ± 0.14 A respectively. For

fuel time ( tr) and fuel volume ( t), the uncertainties are taken as ± 0.2 sec and

± 0.1 sec respectively.

A sample calculation is given below

Example:

Speed N = 1500 rpm

Voltage V = 230 volts

Current I = 14 A

Fuel volume fx = 10 cc

Brake power BP = 3.74 kW

1. Brake power

kW1000 x

VIBPg

BP = f(V,I)

0.016279)(0.86x1000

14)(0.86x1000

IVBP

0.267441)(0.86x1000

230)(0.86x1000

VI

BP

2BP

2BP

BP IVIV (A11.3)

155

22 14.0267441.03016279.0 xx

= 0037868.0

= 0.061536 kW

Therefore, the uncertainty in the brake power from equation A11.3 is

± 0.061536 kW and the uncertainty limits in the calculation of B.P are 3.74 ±

0.061536 kW.

2. Total fuel consumption (TFC)

1000)(t x0.85 x3600 x10TFC

hkg /1.044371000) x(29.3

0.85 x3600 x10TFC

TFC = f(t)

1000 xt0.85) x3600 x(10

Ttfc

2

035643.01000 x(29.3)

0.85) x3600 x(10Ttfc

2 kg/h

2

ttxt

TFCTFC (A11.4)

2)2.0035643.0( x

= 0.0071286 kg/h

The uncertainty in the TFC from equation A11.4 is 0.0071286 kg/h and

the limits of uncertainty are (1.04437) ± (0.0071286) kg/h.

3. Brake thermal efficiency ( )

156

CV xTFC100 x3600 xBP

= f (BP, TFC)

%98135.2943000 x1.04437

100 x3600 x3.74

43000xTFC100) x(3600

BP

016405.843000) x(1.04437100 x3600

43000 x(TFC)100) x3600 x(BP

TFC 2

43000 x(1.04437)100) x3600 x(3.74

2

= 28.70 %

2

TFCxTFC

BPxBP

(A11.5)

22 )0071286.070.28()061536.0016405.8( xx

= 0.53403 %

The uncertainty in the brake thermal efficiency from equation A11.5 is

± 0.53403 % and the limits of uncertainty are 29.98135 ± 0.53403 %

4. Exhaust Gas Temperature Measurement

Al/Cr K-type thermocouple is used to measure the exhaust gas

temperature. Digital temperature indicator displays the temperature measured

by thermocouple. The maximum possible error in the case of temperature

157

measurement is calculated from the minimum values of the temperature

measured and accuracy of the instrument (thermocouple with temperature

indicator) the errors in the temperature measurement are:

T/T)EGT = (( Tk-Type/ Tk-Type)2 + ( Tindi/ Tindi )2)1/2

T/T)EGT = ((0.48/160)2 + ( 0.468/ 160 )2)1/2

T/T)EGT = 0.0041 =0.41%

5. Combustion chamber pressure measurement

The combustion chamber pressure was measured by using pressure

transducer and charge amplifier.

P/P)Exp = (( q charge / qcharge)2 + ( VPT/ VPT )2)1/2

P/P)Exp = ((0.16/ 100)2 + (0.15/ 100)2)1/2 = 0.002193= 0.22%

6. Percentage of uncertainty for the measurement of speed, mass flow rate

of air, mass flow rate of diesel, NOx, hydrocarbon and smoke is given below:

i) Speed : 1.1

ii) Mass flow rate of air : 1.3

iii) Mass flow rate of diesel : 1.0

iv) NOX : 1.1

v) Hydrocarbon : 0.01

vi) CO : 0.8

vii) CO2 : 1.2

vi) Smoke : 2.0

158

APPENDIX 12

HEAT RELEASE ANALYSIS

The details about combustion stages and events can be determined

by analyzing the heat release rates determined from cylinder pressure

measurements. Analysis of heat release can help to study the combustion

behaviour of the engine. The analysis for the heat release rate is based on the

application of first law of thermodynamics for an open system. It is assumed

that the cylinder contents are homogeneous mixture of air and combustion

products and are at uniform temperature and pressure during the combustion

process. The first law for such a system is written as

dQhr = dU + dW + dQht (A12.1)

where,

dQhr = Instantaneous heat release modeled as heat transfer to the working

fluid

dU = Change in internal energy of the working fluid

dW = Work done by the working fluid

dQht = Heat transmitted away from the working fluid (to the combustion

chamber walls)

Change in internal energy is written as,

dU = Cv/R (pdV+Vdp) (A12.2)

159

Work done by the working fluid dW = pdV

Heat transfer rate to the wall is written as dQht/dt = h A (Tg-Tw) (A12.3)

where R = Gas constant

T,P,V are Temperature, Pressure and Volume respectively.

Cv = Specific heat at constant volume

h = Heat transfer co efficient

Tw = Temperature of the wall: 400 K

8.055.08.02.026.3 wTpBh

Where

B (bore) = 0.080 m

P(cylinder pressure) = 29.327 bar

T (gas temperature) = 2100 K

w is average gas velocity in m/s which is calculated from the equation

)(21 mcc

cdp pp

VpTV

CSCw (A12.4)

Where

SP is the mean piston speed in m/s, Vd is the displaced volume in m3

Tc, pc, Vc are temperature, pressure and volume respectively during combustion

p is the cylinder pressure during combustion

pm is the pressure in motorized condition

C1 is 2.28 and C2 is 3.24x10-3 during combustion

160

From the equation, the first law of thermodynamics can be written as

follows with suitable assumptions:

ddt)TwTg(hA

ddp

11V

ddVP

1dQ sht (A12.5)

Where is the crank angle in degrees

is the ratio of specific heats of the fuel and air

As is the area in m2 through which heat transfer from gas to combustion

chamber walls takes place.

The pressure value is obtained from the cylinder pressure data at

corresponding crank angle. Equation (A12.1) makes it possible to calculate the

heat release rate. The calculated heat release rate is as follows with the given

values

Clearance volume = 3.68x10-5 m3 , Swept volume = 0.00055392 m3

=1.3, Crank radius = 0.055m

Stroke = 0.11 m, Compression ratio = 16.5

At 350O CA the pressure is 31.327 bar and at 351O CA the pressure is 31.614

bar. The heat release rate is

ddt)TwTg(hA

ddp

11V

ddVP

1dQ sht

018.61

2078013.1

1000297128.01

00000480.0293270013.1

3.1htdQ

)018.658106.2000016.61(htdQ

6.87htdQ Joules/ºCA