![105
International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET)
Comparison of brake specific fuel consumption obtained from
experimental and modelling solution
P-V diagram
The P-V diagram obtained from numerical solution is fol-
lowing expected trend of an actual cycle. The steep rise
and decrease of pressure indicate combustion zone of the
engine.
Pressure vs crank angle
Effect of compression ratio on temperature
Compression ratio varied from 16 to 19 and its effect on
temperature and pressure is studied. As compression
ratio increases the peak value of pressure increases but
peak value of temperature decreases. When compression
ratio is increased the peak values of incylinder pressure
and temperature are shifted towards TDC.
SUMMARY OF RESULTS AT FULL LOAD
NUMERICAL SOLUTION
Indicated mean effective pressure =7.04961 bar
Indicated power=4.8723 kW
Friction power=0.7853 kW
Hence brake power=4.8723-0.7853=4.087 kW
EXPERIMENTAL RESULTS
Brake power=3.68kW
Friction power=0.875kW (noted down from Willan's line
method then calculated)
Indicated power=3.68+0.875=4.555kW
Hence indicated mean effective pressure=6.5832 bar
Summary of results
The model gives fairly accurate results when we predict
indicated power and brake power at full load. There is de-
viation of 7%, 11% and 10.25 % in results obtained from
modelling solution to the predicted solution for indicated
power, brake power and friction power respectively.
CONCLUSIONS
1. The model predicts value of friction power and indi-
cated power with an accuracy of 10%.
2. The engine must be operated at 75% of the load for the
lowest possible brake specific fuel consumption.
3. Increase in compression ratio is going to decrease the
peak temperature. Even though in cylinder pressure in-
creases with increase in pressure, emissions vary expo-
nentially with temperature, hence emissions are reduced
when compression ratio is increased.
REFERENCES
[1] M.MaherAbou Al Sood, Mahmoud Ahmed and M.Yousef
Abdel Rahim. Rapid thermodynamic simulation model for
optimum performance of a four-stroke, direct-injection,
and variable-compression-ratio diesel engine, Interna-
tional journal of energy and environmental engineering,
Springer open journal, 2012.
[2] C.Felsch, K.Hoffmann, A.Vanegas, P.Drews, H.Barths,
D.Abel, and N.Peters. Combustion model reduction for
diesel engine control design, 10.1243, 2009.
[3] A.Sakhrieh, E.Abu-Nada, I.AlHinti, A.AlGhandoor,
B.Akash. Computational thermodynamic analysis of com-
pression ignition engine, International Communications
in Heat and Mass Transfer, 37-299–303, 2010.
[4] J.B. Heywood. Internal Combustion Engine Funda-
mentals, New York, McGraw-hill publications, 1988.](https://image.slidesharecdn.com/ijri-te-03-015simulationandanalysisof4strokesinglecylinderdirectinjectiondieselengine-161203052020/85/simulation-and-analysis-of-4-stroke-single-cylinder-direct-injection-diesel-engine-3-320.jpg)
simulation and analysis of 4 stroke single cylinder direct injection diesel engine
- 1. 103 International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET) SIMULATION AND ANALYSIS OF 4 STROKE SINGLE CYLINDER DIRECT INJECTION DIESEL ENGINE Kuricheti N. V. Sravan Kumar1 , Muppidi Rambabu2 . 1 Research Scholar, Department of Thermal Engineering, Aditya College of Engineering and Technology, Surampalem, Andhra Pradesh, India. 2 Assistant Professor, Department of Mechanical Engineering, Aditya College of Engineering and Technology, Surampalem, Andhra Pradesh, India. *Corresponding Author: Kuricheti N. V. Sravan Kumar, Research Scholar,Department of Thermal Engineering, Aditya College of Engineering and Technology, Surampalem, Andhra Pradesh, India. Email: ksravankumar91@gmail.com Year of publication: 2016 Review Type: peer reviewed Volume: III, Issue : I Citation:Kuricheti N. V. Sravan Kumar, Research Schol- ar "Simulation And Analysis of 4 Stroke Single Cylinder Direct Injection Diesel Engine" International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET) (2016) 103-106 INTRODUCTION: Present days new ideas, which are not been discussed two decades ago were considered by automotive manufac- turers. In particular, many leading automotive companies have approached practically the very complicated design ideas with different aspects of diesel/petrol engine design. These aspects have been under extensive theoretical and experimental investigations. The most important aspect of design is aimed to vary the engine compression ratio depending on load, speed, or both. Several trials have been done in that respect with extensive design, experi- mentation, and measurements. All attempts to change the compression ratio are achieved by one or more of the following concepts: 1. Moving the cylinder head 2. Variation of combustion chamber volume 3. Variation of piston deck height 4. Modification of connecting rod geometry (usually by means of some intermediate member) 5. Moving the crankpin within the crankshaft (effectively varying the stroke) 6. Moving the crankshaft axis MATHEMATICAL MODELLING PRESSURE LOSS MODELLING Abstract Whenever an engine is designed and manufactured, it is tested to calibrate brake power, indicated power and friction power. Diesel engine simulation models can be used to understand the combustion performance; these models can re- duce the effort, time while producing engines which fails to meet the requirements. In the present work a thermodynamic simulation model for the performance of a four stroke direct injection diesel engine is modelled. A zero dimensional model has been used as a model to investigate the combustion performance of a single cylinder direct injection diesel engine fuelled by high speed diesel. The numerical simulation was performed at different speeds and compression ratios. The pressure, temperature diagrams vs crank angle are plotted. The simulation model includes sub models for various frictional pressure losses, fuel inflow rate with crank angle. A solution procedure is developed for solving the available equations using numerical methods. An appropriate C++ code is written for brake power, friction power, indicated power, brake thermal efficiency are simulated. Experiment was conducted on available four stroke diesel engine and the model is validated. KEYWORDS: Simulation model, combustion performance, zero dimensional model, numerical simulation, indicated power, brake power, brake thermal efficiency, friction power. International Journal of Research and Innovation in Thermal Engineering (IJRITE)
- 2. 104 International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET) FUEL INFLOW RATE MODELLING Mass flow rate of fuel=mass flow rate of air × fuel air ratio (stoichiometric) × equivalence ratio Volumetric efficiency is taken as 80%, pressure, tempera- ture and gas constant are of intake air (approximated to atmospheric condition). PRESSURE AND TEMPERATURE ESTIMATION Writing the energy balance, the pressure variation with respect to crank angle we get as RESULTS:- EXPERIMENTAL RESULTS Time taken for 20 cc of FC (s) Net Load (kg) BP (kW) FC (kg/hr) BSFC (kg/ kW-hr) BTE (%) IP (kW) ME (%) 120 ---- --- 0.4965 --- --- 0.875 --- 95 1.35 1.004 0.6272 0.6247 13.25 1.879 53.43 78 2.55 1.896 0.7638 0.4028 20.54 2.771 68.42 64 3.75 2.788 0.9309 0.3339 24.78 3.663 76.11 45 4.95 3.68 1.324 0.3598 23 4.555 80.79 EMPIRICAL SOLUTION RESULTS Empirical relations directly give value of required param- eter when the terms in the equations have proper units. The results obtained are fairly accurate when compared to the results obtained from experiments. The empirical relations listed and are coded in C++ including the terms with appropriate units to obtain friction power. PRESSURE LOSS The various pressure losses multiplied by volume and speed and converted into friction power are shown below. Variation of friction power with compression ratio It can be observed from figure that crank case mechani- cal losses, throttling losses and pumping losses are inde- pendent of compression ratio. Piston and blowby losses increase with increase in compression ratio almost lin- early. Variation of fuel consumption with brake power (experimental) Calculation of friction power using Willan’s line method Friction power is found to be 0.875 kW which is 23.78% of the brake power at full load. Comparison of brake specific fuel consumption obtained from experimental and modelling solution.
- 3. 105 International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET) Comparison of brake specific fuel consumption obtained from experimental and modelling solution P-V diagram The P-V diagram obtained from numerical solution is fol- lowing expected trend of an actual cycle. The steep rise and decrease of pressure indicate combustion zone of the engine. Pressure vs crank angle Effect of compression ratio on temperature Compression ratio varied from 16 to 19 and its effect on temperature and pressure is studied. As compression ratio increases the peak value of pressure increases but peak value of temperature decreases. When compression ratio is increased the peak values of incylinder pressure and temperature are shifted towards TDC. SUMMARY OF RESULTS AT FULL LOAD NUMERICAL SOLUTION Indicated mean effective pressure =7.04961 bar Indicated power=4.8723 kW Friction power=0.7853 kW Hence brake power=4.8723-0.7853=4.087 kW EXPERIMENTAL RESULTS Brake power=3.68kW Friction power=0.875kW (noted down from Willan's line method then calculated) Indicated power=3.68+0.875=4.555kW Hence indicated mean effective pressure=6.5832 bar Summary of results The model gives fairly accurate results when we predict indicated power and brake power at full load. There is de- viation of 7%, 11% and 10.25 % in results obtained from modelling solution to the predicted solution for indicated power, brake power and friction power respectively. CONCLUSIONS 1. The model predicts value of friction power and indi- cated power with an accuracy of 10%. 2. The engine must be operated at 75% of the load for the lowest possible brake specific fuel consumption. 3. Increase in compression ratio is going to decrease the peak temperature. Even though in cylinder pressure in- creases with increase in pressure, emissions vary expo- nentially with temperature, hence emissions are reduced when compression ratio is increased. REFERENCES [1] M.MaherAbou Al Sood, Mahmoud Ahmed and M.Yousef Abdel Rahim. Rapid thermodynamic simulation model for optimum performance of a four-stroke, direct-injection, and variable-compression-ratio diesel engine, Interna- tional journal of energy and environmental engineering, Springer open journal, 2012. [2] C.Felsch, K.Hoffmann, A.Vanegas, P.Drews, H.Barths, D.Abel, and N.Peters. Combustion model reduction for diesel engine control design, 10.1243, 2009. [3] A.Sakhrieh, E.Abu-Nada, I.AlHinti, A.AlGhandoor, B.Akash. Computational thermodynamic analysis of com- pression ignition engine, International Communications in Heat and Mass Transfer, 37-299–303, 2010. [4] J.B. Heywood. Internal Combustion Engine Funda- mentals, New York, McGraw-hill publications, 1988.
- 4. 106 International Journal of Research and Innovation on Science, Engineering and Technology (IJRISET) AUTHORS Kuricheti N. V. Sravan Kumar, Research Scholar, Department of Thermal Engineering, Aditya College of Engineering and Technology, Surampalem, Andhra Pradesh, India. Muppidi Rambabu, Assistant Professor, Department of Mechanical Engineering, Aditya College of Engineering and Technology, Surampalem, Andhra Pradesh, India.