5. EXPERIMENTAL RESULTS
The following table shows the change in different
efficiencies depending of the material used as
TBC.
The following graphs show the change in efficiency
and performance for different material used as TBC.
Fig.4: Specific Fuel Consumption vs Brake Power
Fig.5: Brake Thermal Efficiency vs Brake Power
Fig.6: Mechanical Efficiency vs Brake Power
The following tables give the change is emission
observed when different material are used as TBC.
6. RESULT ANALYSIS
Two sets of experiments were conducted with
conventional and TBC coating of zirconiumdioxide
(ZrO2) and titanium dioxide (TiO2) coated pistonon
the piston crown. In each set of tests, readings of
engine speed, load torque, engine power, fuel
consumption, exhaust gas temperature, gas emission
concentration, readings were taken with various
engine loads and various engine speeds (1000 to
4500rpm).
Total fuel consumption has comparatively reduced in
TBC over conventional AL Alloy piston and also
increase in brake thermal efficiency,Indicated thermal
efficiency and also increase in volumetric efficiency.
ZrO2has a better performance over TiO2 and AL Alloy
piston.
When comparing piston coated with ZrO2 and piston
coated with TiO2 it was found that the piston with
ZrO2 coating provided better results than the TiO2 coated piston. The piston with ZrO2 coating provides better efficiency and performance when compared with the TiO2 coated piston. The difference in the efficiency between ZrO2 coated piston and TiO2 coated piston was in the range of 1% to 2%. In the case of air-fuel ratio it was found that ZrO2 coated piston had an air-fuel ratio of 13.26. But the air-fuel ratio of TiO2 coated piston was 11.61. The engine with ZrO2 coated piston also shows better result in fuel consumption when compared with TiO2 coated piston. In the case of emissions it was found that the ZrO2 coated piston emits less CO and HC when compared with TiO2 coated piston. But it is to be noted that both ZrO2 and TiO2 coated piston showed an increase in NOx and CO2 when compared with plain AL alloy piston. The ZrO2 coated piston engine showed a slight increase in NOx and CO2 emissions when compared with TiO2 coated piston engine.