Experiment 1 To draw the performance characteristics of a diesel engine at various constant speed with variable load .
1. Background When an engine runs at constant speed with variable load, engine performance is usually expressed in term of certain parameters such as brake power, specific fuel consumption, various efficiencies, etc. When test is repeated at other speeds, a more complete performance evaluation is obtained. A comprehensive series of o f constant c onstant speed tests will cover the entire operating range of an engine and is a convenient procedure if the test setup is equipped for automatic speed regulation. Numerous factors can be investigated.
2. Objectives o
To find the brake power, specific fuel consumption, and brake thermal efficiency of the engine at various speeds with variable load
3. Equipments A. Engine I. Type: II. Model: III. No. of Cylinders: IV. No. of Strokes: V. Maximum Speed: B. Fuel I. Type: II. Density: III. Calorific value:
4. Procedure A. Initial Operating Checklist
4.1. Check the following: engine oil, coolant and fuel 4.2. Record the specification of engine and fuel B. Initial Operating Checklist
4.3. Start the engine 4.4. With the engine operating at zero load, set the engine speed at 1000 rpm and let it run for 10 minutes C. Initial Operating Checklist
4.5. Adjust the dynamometer load and throttle to obtain 2000 rpm at 3 Nm 4.6. Record the fuel consumption for 2 minutes 4.7. Record the exhaust gas temperature 4.8. Repeat steps 4.6 to 4.8 by increasing load by 3 Nm for each set of reading while maintaining engine speed at 2000 rpm until a load of 18 Nm is reached. 4.9. Repeat steps 4.5 to 4.9 for engine speeds of 3000 rpm and 4000 rpm.
5. Report 5.1. Record all the data 5.2. Compute the results 5.3. For various engine speeds, plot the following versus engine brake power: a. Fuel consumption b. Specific fuel consumption c. Brake thermal efficiency d. Exhaust gas temperature e. Relative air fuel ratio
6. Discussion Discuss the experimental results based on the calculations and the performance curves
7. Conclusion Make your conclusion based on the results and your discussion.
Experiment 2
To draw the performance characteristics of a spark ignition engine at various constant speed with variable load .
1. Background When an engine runs at constant speed with variable load, engine performance is usually expressed in term of certain parameters such as brake power, specific fuel consumption, various efficiencies, etc. When test is repeated at other speeds, a more complete performance evaluation is obtained. A comprehensive series of constant speed tests will cover the entire operating range of an engine and is a convenient procedure if the test setup is equipped for automatic speed regulation. Numerous factors can be investigated.
2. Objectives o
To find the brake power, specific fuel consumption, and brake thermal efficiency of the engine at various speeds with variable load
3. Equipments A. Engine I. Type: II. Model: III. No. of Cylinders: IV. No. of Strokes: V. Maximum Speed: B. Fuel I. Type: II. Density: III. Calorific value:
4. Procedure A. Initial Operating Checklist
4.1. Check the following: engine oil, coolant and fuel 4.2. Record the specification of engine and fuel B. Initial Operating Checklist
4.3. Start the engine 4.4. With the engine operating at zero load, set the engine speed at 1000 rpm and let it run for 10 minutes C. Initial Operating Checklist
4.5. Adjust the dynamometer load and throttle to obtain 2000 rpm at 3 Nm 4.6. Record the fuel consumption for 2 minutes 4.7. Record the exhaust gas temperature 4.8. Repeat steps 4.6 to 4.8 by increasing load by 3 Nm for each set of reading while maintaining engine speed at 2000 rpm until a load of 18 Nm is reached. 4.9. Repeat steps 4.5 to 4.9 for engine speeds of 3000 rpm and 4000 rpm.
5. Report 5.1. Record all the data 5.2. Compute the results 5.3. For various engine speeds, plot the following versus engine brake power: a. Fuel consumption b. Specific fuel consumption c. Brake thermal efficiency d. Exhaust gas temperature e. Relative air fuel ratio
6. Discussion Discuss the experimental results based on the calculations and the performance curves
7. Conclusion Make your conclusion based on the results and your discussion.
Experiment 3 To draw the performance characteristics of a spark ignition engine at various constant throttle settings with variable load .
1. Background In describing or rating a particular spark-ignition automotive engine, the peak brake power, peak brake torque, and minimum brake specific fuel consumption (bsfc) are the common measures. These are determined from the usual dynamometer test, in which the runs are made at full throttle over the entire speed range of the engine and then repeated at part-throttle settings which will produce selected fractions of the full-throttle load.
2. Objectives o
To find the brake power, brake specific fuel consumption (bsfc), brake mean effective pressure (bmep), and brake thermal efficiency at various constant throttle settings with variable load
3. Equipments A. Engine I. Type: II. Model: III. No. of Cylinders, n: IV. No. of Strokes: V. Maximum Speed [rpm]: 2
VI. Area of piston, A [m ]: VII. Length of stroke, L [m]: B. Fuel I. Type: II. Density: III. Calorific value [kJ/kg]:
4. Procedure A. Initial Operating Checklist
4.1. Check the following: engine oil, coolant and fuel 4.2. Record the specification of engine and fuel B. Initial Operating Checklist
4.3. Start the engine 4.4. With the engine operating at zero load, set the engine speed at 1000 rpm and let it run for 10 minutes C. Initial Operating Checklist
4.5. Set the throttle at 100% with zero load 4.6. Record the engine speed 4.7. Record the fuel consumption for 2 minutes 4.8. Repeat steps 4.6 to 4.8 by increasing load by 3 Nm for each set of reading while maintaining throttle setting until a load of 18 Nm is reached. 4.9. Repeat steps 4.5 to 4.9 for throttle setting of 75%, 50% and 25%.
5. Report 5.1. Record all the data 5.2. Compute the results 5.3. For various throttle settings, plot the following versus engine speed: a. Fuel consumption b. Engine torque c. Brake Power d. Brake Specific Fuel Consumption e. Brake Mean Effective Pressure f.
Brake thermal efficiency
g. Relative air fuel ratio
6. Discussion Discuss the experimental results based on the calculations and the performance curves
7. Conclusion Make your conclusion based on the results and your discussion.
8. Formulas 2 π N T
(i)
Brake Power, bp =
(ii)
& f Rate of Fuel Mass Flow, m
(iii)
Brake Specific Fuel Consumption, bsfc =
(iv)
Brake Mean Effective Pressure, bmep =
(v)
Brake Thermal Efficiency, η BT
60 × 1000
[kW]
=
m f
2 × 60
=
[g/s]
& f m
×
3600
bp × 1000
[kg/kWh]
bp × 60 × 2 n × A × L × N × 100
bp × 1000
& f m
×
Qnet ,V
[bar]
