Problem statement: Water injection into the combustion chamber of diesel engine found to be one of best method for in-cylinder control of NOx formation. Approach: The combustion of waterdiesel emulsion in diesel engine was simulated using a computer program to estimate the heat release rate, cylinder pressure, brake thermal efficiency, brake specific fuel consumption and NO formation. Results: The numerical simulation was performed at different equivalence ratios, engine speeds and water percentages. The numerical simulation was preferred to study the combustion behavior and emission of diesel engine because the experimental investigations were time consuming and costly affair. Conclusion/Recommendations: Experiments also conducted to validate the predicted results of computer simulation. Though the zero dimensional simulation models predicted NO formation during combustion process, the first appearance of NO could not be identified using this method which can be solved by CFD technique.

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In the present work, the heat dissipation rate and thermal resistance of electronic cooling system is investigated with different coolants by two-phase closed loop thermosyphon method for both steady and unsteady state conditions. The coolants used in this study are acetone, alcohol and petrol respectively and are poured in the created test facility. A square heater of size 35 × 35 mm is fixed in the primary tank and used as a heat source. The heat input is given to the system varies from 10 to 60 W. The temperature of the experimental setup is measured by seven K-type thermocouples which are attached at various locations. Results indicate that (i) the convective heat transfer coefficient increases and thermal resistance decreases with increasing of heat input for all the coolants (ii) the acetone has high heat removal rate of 65.4 % at 60 W due to low boiling point, high latent heat of evaporation and less effect on subcooling, which directly helps in phase change process and heat extraction rate (iii) a maximum reduction in thermal resistance of about 0.523 0 C/W for acetone in comparison with alcohol and petrol by virtue of its high superheat which accelerates to nucleate boiling.

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