ERKEL Daniel Combustion SI Engine-Laboratory Report

7/29/2019 ERKEL Daniel Combustion SI Engine-Laboratory Report

1/30

DEPARTMENT OF MECHANICAL ENGINEERING

CODE AND TITLE OF COURSEWORKCourse code:

MECH2004:

Title:

Combustion in a Spark Ignition Engine

STUDENT NAME: ERKEL, DANIEL

DEGREE AND YEAR: EBF, 3rd YEAR

LAB GROUP: -

DATE OF LAB. SESSION: -

DATE COURSEWORK DUE FOR SUBMISSION: 15/03/2013

ACTUAL DATE OF SUBMISSION: 15/03/2013

LECTURERS NAME: Dr William Suen, Midhat Talibi

PERSONAL TUTORS NAME: Dr Kevin Drake

RECEIVED DATE AND INITIALS:

I confirm that this is all my own work (if submitted electronically, submission will be taken asconfirmation that this is your own work, and will also act as student signature)

Signed: Daniel Erkel


2/30

Daniel Erkel Combustion in a Spark Ignition Engine

Contents

1 Introduction 2

2 Results 2

2.1 Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.1.1 Initial Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22.1.2 Results from the Experiment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.2 Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32.3 Graphs Plotted for Question 4.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 Discussion of Results and Answers to the Questions 7

3.1 Question 4.1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.1.1 Commenting on the Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.1.2 Explanation of the Results, Comparison with Theoretical Data and Calibrating for

Engine Performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73.2 Question 4.2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83.3 Question 4.3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93.4 Question 4.4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

3.5 Question 4.5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93.6 Question 4.6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103.7 Question 4.7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103.8 Question 4.8 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4 Conclusion 11

5 Appendices 13

5.1 Hand Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135.2 Aims, Theory and Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

1


3/30

Mechanics of Fluids and Thermodynamics - Laboratory Report

Combustion in a Spark Ignition Engine

Daniel Erkel, 3rd year, EBF

1 Introduction

In the course of the experiment discussed in the present report, a Ricardo E6 spark ignition engine wasused to demonstrate certain characteristics of the operation of spark ignition engine. In the spark ignitionengine, which is one of two types of reciprocating internal combustion engines [1], the air-fuel mixture isignited in the combustion chamber to initiate the combustion, which then expands and moves the pistonoutwards, which in turn rotates the crankshaft connected mechanically, thus converting the energy of thecombustion to mechanical work [2].

Varying a set of parameters that control the operation of the engine, changes in its working was observed.Through eight questions, relationships between the air-to-fuel ratio and performance characteristics are dis-cussed using the results of the experimental section. Performance is measured in terms ofbrake power, brakespecific fuel consumption (or BSFC), thermal efficiency and emission values. Sections of this report compareexperimental results with those predicted using theoretical analysis and textbook values, discussing pointswhere the two coincide and also where discrepancies were found between ideal values or those measured inmore controlled experiments and the findings of this laboratory experiment.

2 Results

2.1 Measurements

2.1.1 Initial Data

Initial data describing the environmental conditions, material properties and engine properties are presentedin the following table:

Table 1: Table with the initial data recorded for environmental conditions, material properties and engineproperties

Environmental Conditions and Material Properties Value

Ambient pressure (mbar) 1022Ambient pressure (Pa) 102200Calorimeter water flow rate (l/h) 450Fuel density (kg/m3) 733Mass of 50ml fuel (kg) 0.03665Air density at (kg/m3) 1.2063

Engine properties Value

Bore (mm) 76.2Stroke (mm) 111.13Cylinder swept volume (m3) 0.0005068Motoring torque at 1500 rpm - cold engine (Nm) 11.5Motoring torque at 1500 rpm - hot engine (Nm) 9Engine rev. per power stroke 4

2


4/30


Cylinder swept volume was calculated using following equation from (Ref. [3]) the values for the boreand the stroke as:

Vswept =

Bore

2

2

(Stroke) =

0.0762

2

2

(0.11113) = 0.0005068m3

The air density was interpolated using Ref. [4] assuming a room temperature of 20C. While the roomtemperature was probably lower in the air conditioned laboratory where the experiment was conducted,

close to the engine it was slightly higher due to the heat given off by the engine.

2.1.2 Results from the Experiment

The following values were measured in the course of the experiment

Table 2: Add caption

Measurement no.: 1 2 3 4 5

Measured values

Engine Speed (rpm) 1504 1503 1501 1502 1503

Motor torque (Nm) 33 34 33 31.5 29Intake temp (C) 9.5 10.2 10.5 10.9 10.8Time for 50ml fuel to be used (s) 65 71 76 80 85Air flow, A (cmH2O) 4.5 4.6 4.6 4.65 4.6CO (%) 6 4 2 1 0.95Oil temp (C) 31 37 40 40 43Cooling water temp in (C) 37 37.7 37.8 37.5 37.6Cooling water temp out (C) 42.1 41.6 41.6 41.7 41.3Calorimeter water temp in (C) 9.4 9.6 9.7 9.9 10.2Calorimeter water temp out (C) 20 20.3 20.6 20.7 21Engine cooling water flow rate (l/min) 6.4 6.7 6.8 6 6.4

2.2 Calculations

Using the values from the previous section, the following values were calculated:

Table 3: Derived values

Measurement no.: 1 2 3 4 5

Derived values

Brake Power, Pb (W) 5197.5 5351.4 5187.1 4954.6 4564.4Pb (kW) 5.197 5.351 5.187 4.955 4.564Fuel Flow Rate, Mf (kg/h) 2.030 1.858 1.736 1.649 1.552BSFC (kg/kWh) 0.391 0.347 0.335 0.333 0.340Air Mass Flow Rate, Ma (kg/s) 0.00753 0.00753 0.00753 0.00753 0.00753Fuel Flow Rate, Mf (kg/s) 0.000564 0.000516 0.000482 0.000458 0.000431Air-Fuel Ratio, AFR 13.356 14.588 15.616 16.438 17.465Friction Power, coldPf (kW) 1.811 1.810 1.808 1.809 1.810Friction Power, hotPf (kW) 1.417 1.417 1.415 1.416 1.417Engine Mechanical Efficiency, cold 0.742 0.747 0.742 0.733 0.716Engine Mechanical Efficiency, hot 0.786 0.791 0.786 0.778 0.763

BMEP (Pa) 1636504 1686096 1636504 1562118 1438140

The following equations were used to calculate the above values:

Pb = 2NT (1)

3


5/30


Pf = 2NTm (2)

BSFC= Mf/Pb (3)

m =Pb

(Pf + Pb)(4)

BMEP=2nrT

V(5)

Which equations can be found in Ref. [3]. The following section shows the graphs plotted for these results.

4


6/30


2.3 Graphs Plotted for Question 4.1

Using the derived values from the previous section, the following four graphs were plotted. The discussionof these results are found in the next section.

Figure 1: Brake Specific Fuel Consumption plotted against Air-to-fuel ratio plotted for part a)

Figure 2: Brake power plotted against Air-to-fuel ratio plotted for part b)

5


7/30


Figure 3: Brake Specific Fuel Consumption plotted against Brake power plotted for part c)

Figure 4: Carbon monoxide (%) plotted against Air-to-fuel ratio plotted for part d)

The thin black lines are third-order polynomial trend lines, which, as it can be seen from the graphs,perfectly fit the data. The thick green line is generated for the scatter plot in Microsoft Excel.

6


8/30


3 Discussion of Results and Answers to the Questions

3.1 Question 4.1

3.1.1 Commenting on the Results

(a) The graph plotted for part (a) is close to a parabola in its shape (although a cubic curve fittedbetter to the data). The minimum point of the curve was found taking the equation for the trendline

from Microsoft Excel (using coefficients with 15 decimal places for better accuracy) and solved inWolframAlpha (an computational knowledge engine, a website capable of solving simple equations) tofind the minimum. The minimum was found at AFR = 16.094 and BSCF= 0.333kg/kWh. This isto right of the stoichiometric air-to-fuel ratio for gasoline, which is equal to 14.7:1 [5].

(b) The second graph is very similar in shape to the previous one (parabola or a section of a cubic curve),however it is concave in the other direction (as in it is the vertical reflection of the previous one). Themaximum point of this curve is at AFR = 14.409 and is equal to 5351.783W. Again, this result isdifferent from the stoichiometric ratio, being to the left of it.

(c) The backward curving graph has a minimum value of BSCF = 0.333kg/kWh, equal to that of (a)and the maximum brake power is equal to that found in (b), 5351 .783W.

(d) From the shape of the cubic curve it can be observed that carbon monoxide emission decreases withincreasing air-to-fuel ratio, up till about AFR = 16.978, beyond which it starts increasing again.

3.1.2 Explanation of the Results, Comparison with Theoretical Data and Calibrating for

Engine Performance

(a) The curve is similar to that found in [6], therefore matches results predicted by textbooks. Enrichmentof the fuel results in incomplete combustion (high amount of fuel but not enough air for completecombustion). Making the fuel more lean (i.e. moving towards the right side of the curve) resultsin better combustion and better power output up till the minimum point of the curve. The graphsshows a relationship between brake specific fuel consumption and air-to-fuel ratio, the former of whichis value expressing the relationship of power and fuel flow rate. Because of this the behaviour ofthe curve is determined by how the power and the fuel flow rate respond together to making thefuel more lean (lowering the amount of fuel in AFR) or making it more rich (increasing the amounof fuel in AFR). The fuel consumption decreases towards the ideal point of air-fuel mixture (thestoichiometric ratio). The reason why the stoichiometric ratio does not coincide with the minimumpoint of the curve is because in reality slightly more fuel is necessary to react with all the air moleculesin the combustion chamber during the actual operation of the engine, where not all fuel moleculesparticipate in the combustion, due to losses in the engine running at high speed [6]. This means thatat the stoichiometric ratio the consumption would not be the lowest, that point is somewhere in theleaner region. Slightly leaner mixture lowers the fuel flow rate, but with the power not decreasingthat much, BSFC is lower.

(b) The curve again corresponds to ones find in textbooks such as [2] or [6]. This time it is the brake powerplotted against AFR. With increasing AFR the amount of air in the combustion chamber exceeds thatnecessary for the combustion and the power output is lowered. Richer mixtures generate higher poweroutput up till a maximum point, beyond which there are higher specific heats and losses in chemicalequilibrium and also there is a wastage of fuel due to the generation ofCO and H2. Again, for reasonssimilar to those in part (a), the stoichiometric ratio is not the maximum point of the curve. This timea richer mixture is necessary, because more fuel is needed for the combustion with the highest poweroutput, than that predicted theoretically [6].

(c) The so-called combustion loop [6] is a combination of the two previous curves with the lean and rich

regions being below and above the curve, respectively. The results match those found in similarexperiments discussed in textbooks (e.g. Ref. [6]). Enrichment of the mixture results in better poweroutput but worse fuel consumption and vice versa.

7


9/30


(d) A higher amount of fuel in the mixture results in a higher carbon monoxide emission. Increasing theamount of air (making the mixture more lean) results in lower CO output up till a point, beyondwhich due to the incomplete and inefficient combustion, the CO emission starts increasing (there willalways be a small amount of CO output). This matches theoretical expectations [6]

The curve of part (c) shows how varying the air-to-fuel ratio can change the performance and fuel consump-tion of the engine and how this property can be used to tune the vehicle for better fuel consumption (more

important in the case of a family car or a vehicle that is meant for everyday use) or high power output (as itwould be desired in the case of a racing car). The optimum can be found for cars where both properties areimportant, such as gran tourismo or grand tourer cars, where one needs both good fuel consumption, butalso a high power output for high-speed travel on highways. There may be certain errors in the experimentalresults due to errors in measurements, due to the quality of the engine used for the experiment (which wasan older model) and also due to small changes in environmental conditions.

3.2 Question 4.2

Observing the third graph, which shows the combustion loop, the lowest value for brake specific fuel con-sumption is BSCF= 0.333kg/kWh. At this point the following calculations are performed:

(a) The amount of energy in the fuel converted to useful power output from the engine can be calculatedthrough the following steps. The calorific value of the fuel being equal to 45.5MJ/kg means that1kg of fuel should provide 45.5MJ energy, which, dividing by 3600s would mean 12.639kW powerprovided to the engine. At the lowest recorded BSFC value however (also the minimum point of thecombustion loop) 0.333kg of fuel consumed per hour produces 3.003kW useful power. This meansthat the amount of fuel energy that generates useful power output is:

%useful =3.003

12.639 100 = 23.8%

Which shows that not even one third of the energy stored in the fuel is converted in this spark ignitionengine to useful power output.

(b) At the lowest recorded value of BSFC the mass flow rate of the engine cooling water is equal to6l/min. This converted to m3/s is equal to 0.0001m3/s and converted to kg/s is equal to 0.1kg/s.The change in cooling water temperature (difference between the inlet and exit temperatures) is equalto T= 41.7 37.5 = 4.2C. From this, the heat energy lost is calculated as:

Qcool = mwCT= 0.1 4200 4.2 = 1.764kW

where C= 4200J/kgK is the specific heat capacity of water. From this, the proportion of fuel energythat is lost as heat to the cooling water is

%heatcool =1.764

12.639 100 = 13.95

Which means that nearly 15% of the fuel energy is transferred as heat to the cooling water

(c) The amount of energy that is used to elevate the temperature of the exhaust gases above the ambientvalue is calculated in a similar way as the heat lost to the cooling water. The mass flow rate this timeis measured for the calorimeter water (450l/h), just as the temperature difference between the outletand inlet (T = 20.7 9.9 = 10.8C). Using the values from the table in the Measurements sectionthe following equation can be written up:

Qelev = mwcalCT= 0.125 4200 10.8 = 5.670kW

where C= 4200J/kgK is again the specific heat capacity of water. The proportion of fuel energy thatis used to elevate the temperature of the exhaust gases above ambient is then obtained as:

%heatelev =5.67

12.639 100 = 44.86%

This means that nearly half (!) of the fuel energy is used to elevate the temperature of the exhaustgases.

8


10/30


It can be seen that the percentages calculated above only add up to 82.6%, which means that there arefurther energy losses. These can be: heat energy lost to the air, losses in excess fuel, or sound, vibrationand frictional losses. Of course there can also be errors in the above measurements or calculations. Readingscales, measuring flow rates or heat all introduce certain errors. Furthermore the actual calorific value ofthe fuel also might be slightly different, just as the real values of other variables.The theoretical value for the Otto cycles efficiency is (from [3]):

Otto = 1

r1

Where r is the compression ratio of the engine, which in our case is equal to 8. From this the thermalefficiency of the engine should be:

Otto = 1 811.4

100 = 56.5%

The value calculated in this report (23.8%) is less than half of this, which is a big difference. Although theengine is also somewhat old, one of the main reasons for this is that the compression ratio used here is notideal for the engine. To a certain practical limit [2], this can be raised to increase the efficiency.

3.3 Question 4.3

The maximum of graph (b) in Question 4.1 is 5351.4W. The friction power for motoring torque in thecold engine is 1810W and at for the hot value it is 1417W at this brake power output. Calculating themechanical efficiencies gives:

mechcold =5351.4

1810 + 5351.4 100 = 74.73%

mechhot =5351.4

1417 + 5351.4 100 = 79.06%

The second value is higher as the running engine is better lubricated and lower amounts of energy are lostdue to the viscous friction resulting. These frictional losses are due to the viscosity of the oil lubricating the

engine. If the engine is already warmed up, the viscosity of the oil lowers and less power is dissipated [2]

3.4 Question 4.4

Pressing the throttle pedal (or turning the throttle handle on a motorcycle) opens the throttle more in theengine, increasing the charge going into the cylinder and hence controlling the combustion [6]. With openingthe throttle the torque and power outputs of the engine increase. Which in turn results in higher speed ofthe engine (and the vehicle), this however also depends on the load on the engine (as in the response of thevehicle to changing the throttle depends on the steepness of the road and other circumstances). The useof the throttle (when it is closed) lowers the Otto cycle efficiency of the engine due to pumping losses [2].When the throttle is not fully open, during the intake stroke, a certain amount of power is lost as there is

a low pressure area near the inlet manifold, which has to be overcome by the air entering the cylinder [2].Pumping losses appear on the P V diagrams attached in the Appendix of this report. At part load theloop at the bottom of the P V indicator diagram, the part with which the cycle differs from the graphfor the ideal Otto-cycle, is the result of the pumping loss. This loop is almost insignificant in the case ofthe wide open throttle (WOT).

3.5 Question 4.5

On the P V diagrams attached in the Appendix three different cases can be seen, the first one showsthe engine operating with a wide open throttle (WOT) the second one shows a case where the engine isknocking and finally on the third one it can be seen how the engine behaves under part load. The peak

of each graphs correspond to the the point where the combustion starts in the engine and is different forthe three different cases. For the same compression ratio it is higher for the WOT condition than for thepart load. In the case of the knocking, the pressure is very high, but this is because in order to achievethe auto-ignition condition where the knocking starts, the compression ratio of the engine has to be raised(this is also why the compression ratio cannot be increased indefinitely, because knocking occurs [2]). As

9


11/30


discussed earlier, the small loop at the bottom of the curve is the effect of the pumping losses in the intakestroke, which is perceivably smaller for the WOT condition, almost negligible, and much larger for the partload. Nevertheless the engine cannot be constantly operated at WOT as in certain cases the part load ismore desired (under realistic conditions, the engine does not need to produce maximum power).Knocking is the result of reaching auto-ignition conditions in the engine, by raising the compression ratiofor example, and is detrimental to the engine, because the small explosions in the cylinder (where the fuelauto-ignites) causes uneven combustion, damage to the piston, and through the loss of timing also damages

the crankshaft and other components [6]. The small peaks on the graph for the knocking show the smallexplosions occurring during the combustion. There are many ways to improve the efficiency of the engine.Two common ones are to use super- and turbochargers, which compress the air entering the cylinder andhence improve the combustion. Also fuel injectors and better exhausts can be added to the engine as othermeans of increasing the power output.The BMEP for the part load (WWMP) and the WOT conditions can be calculated using the torque as

BMEP=2 2 T

Vswept

From this, using the torque value at 1500rpm (cold) for the part load and that obtained for the rpm closestto 1500 (1501rpm at CO=2%):

BMEPWWMP =2 2 11.5

0.0005068= 2.85bar

and

BMEPWOT =2 2 33

0.0005068= 8.18bar

BMEP, brake mean effective pressure shows useful work output [6], which is evidently higher for the wideopen throttle as it can be expected from the higher torque as well. Thus operating at WOT gives higheruseful work output

3.6 Question 4.6

As certain conditions change in the environment of and in the engine as well, there are variations in theengines output. The air entering the intake for example or the combustion in the combustion chamber bothvary slightly, therefore there are constant changes in the engines operation. Regarding the latter, one ofthe reasons for the variation is that after each combustion, a different amount of combustion residuals areleft in the cylinder and these also affect the next cycle. There are further conditions that vary, such as thequality of the air, the temperature of the air and the surroundings of the engine, the turbulence in the airflow (which is quite difficult to predict). Furthermore, depending on the road on which the vehicle travels,there can be vibrations that affect the engines performance. Finally as the engines material is not a 100%perfect, there can be regions, which have slightly different material properties, for example different heatcapacity and cool down slightly less than other parts, which then results in differences between the different

cycles.These conditions that affect the engine performance are often difficult to predict and even more difficultto control. For example while engine manufacturers attempt to create perfect molds, no material canbe without infinitesimally small imperfections, therefore this it is really difficult to control how these affectperformance. This also applies to the turbulence of the air that enters the cylinder, which designers attemptto control, yet even the most sophisticated turbulence models in computational fluid dynamics calculationsare not a 100% accurate, therefore it cannot be fully controlled how the air will enter the piston [7], [6].

3.7 Question 4.7

The sound of the combustion in the cylinders changes at higher compression ratios due to the phenomenon of

knocking discussed previously answering Question 4.5. Knocking is named after the very sound it generates,and it is caused by auto-ignition at conditions when the air-fuel mixture reaches auto-ignition temperatureinside the cylinder [6]. It is very dangerous as it destroys not only the cylinder (as the uncontrolled micro-explosions at the different parts of the combustion chamber introduce additional load to the material andcause small deformations), but also because it changes the rhythm of the cycle and the timing, it affects

10


12/30


almost all parts of the engine, from valves to the crankshaft. This way knocking not only reduces theperformance of the engine but can have permanent destructive effects on the engine [?]. There it should beavoided at all costs. The reason why it is not always easy to avoid it, because certain conditions change inthe cylinder gradually, or for example oil or other fluids can enter the combustion chamber, in which casethe air-fuel mixtures properties can change. Also, manufacturers would seek a high-as-possible compressionratio because the efficiency and the power output of the engine increase with compression ratio, limited byknocking and material wear due to high temperature and pressure.

The reason for the small peaks on the PV graph of the cycle with knocking was discussed previously.

The small peaks are caused by the small combustions occurring at various times during the power stroke.To avoid knocking even at high compression ratios, certain additives can be added to the fuel. Lead wasone of such additives, but it was later found that it pollutes the environment in a very serious way. Nowthere are experiments with additives less efficient than lead, but also less dangerous to the environment [6].

3.8 Question 4.8

The O2 sensor in cars detects the richness of the air-fuel mixtures (the AFR). Mixtures that are more richhave generate a lower amount of oxygen after the combustion, while lean mixtures generate higher. Afeedback system connected to the O2 sensor than adjusts the mixture to achieve optimum combustion, the

process of which is controlled by a small on-board computer. This system can be used to achieve the controlover the engine performance that was discussed previously in relation to the combustion loop or graph (c) inQuestion 4.1. This way the performance and the fuel consumption of the car can balanced or tuned towardsone or the other in order to obtain a vehicle with high performance (such as a racing car) or one with a lowfuel consumption (such as a car that one would want to us in a city) [6].

4 Conclusion

Understanding of the parameters and relationships examined in this experiment are very important to gaincontrol over the performance and fuel consumption of the internal combustion engine. The understandingof these phenomena are vital to motor engineers and also to all working with any types of IC engines. The

experiment well demonstrated the result of changing the AFR values amongst others on BSFC, brake powerand CO emission.Furthermore the experiment successfully demonstrated the phenomenon of knocking, which is also veryimportant to understand possible design limitations of SI-IC engines.The present report found answers to all questions stated in the handout for the laboratory experiment andfound strong correspondence between theoretical or experimental data from textbooks and the experimentalmeasurements taken during the laboratory session.

References

[1] Y. Cengel and M. Boles, Thermodynamics: An Engineering Approach with Student Resources DVD.

McGraw-Hill Education, 2010.

[2] V. Kadambi and M. Prasad, Introduction to Energy Conversion. An Introduction to Energy Conversion,John Wiley & Sons Australia, Limited, 1974.

[3] B. Venkanna and B. Swati, Applied Thermodynamics. PHI Learning, 2011.

[4] G. Rogers and Y. Mayhew, Thermodynamic and Transport Properties of Fluids. Wiley, 1995.

[5] B. Hollembeak, Classroom Manual for Automotive Fuels and Emissions. Todays technician, Thom-son/Delmar Learning, 2005.

[6] V. Ganesan, Internal Combustion Engines 3e. McGraw-Hill Education (India) Pvt Limited, 2008.[7] B. Munson, D. Young, T. Okiishi, and W. Huebsch, Fundamentals of fluid mechanics. Wiley, 2009.

11


13/30


List of Figures

1 Brake Specific Fuel Consumption plotted against Air-to-fuel ratio plotted for part a) . . . . 52 Brake power plotted against Air-to-fuel ratio plotted for part b) . . . . . . . . . . . . . . . . 53 Brake Specific Fuel Consumption plotted against Brake power plotted for part c) . . . . . . 64 Carbon monoxide (%) plotted against Air-to-fuel ratio plotted for part d) . . . . . . . . . . 6

List of Tables

1 Table with the initial data recorded for environmental conditions, material properties andengine properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

2 Add caption . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 Derived values . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

12


14/30


5 Appendices

5.1 Hand Calculations

Pb = 2nT = 2 1500

60 33 = 5183.6W

BSFC=mfPb

=2.03

5.197= 0.39055kg/kWh

BMEP=2nT

Vswept=

2

2

33

0.0005068= 1636504Pa

13


15/30


5.2 Aims, Theory and Diagrams

These are attached to this document from the laboratory handout (starting from the next page).

14


16/30


17/30


18/30


19/30


20/30


21/30


22/30


23/30


24/30


25/30


26/30


27/30


28/30


29/30


30/30

Documents

ERKEL Daniel Combustion SI Engine-Laboratory Report