a) Sketch the P-v diagrams for the ideal air standard Otto 4 stroke cycle, the ideal air standard 4 stoke Diesel cycle. Please indicate: i) The volume at top dead centre and bottom dead centre. ii) The position of the heat addition on each diagram. b) An ideal air standard Otto cycle operates with a bore of 7 cm, a swept length of 6.5 cm and a clearance length of 1 cm. (Assume Ya 1.4). Calculate- i) the compression ratio. ii) the Otto cycle efficiency. c) A four cylinder, 4 stroke internal combustion engine has a bore of 60mm and a stroke of 70mm, At a test speed of 3000 rev/min it is operated against a brake which has a torque arm of 0.40m and the measured brake load is 160N. Calculate: i) The engine torque ii) The brake power iii) The bmep. iv) The imep. assuming that the mechanical efficiency of the engine is 0.85. d) Comparing the ideal air standard Otto 4 stroke cycle with the ideal air standard 4 stoke Diesel cycle. i) State how does the thermal efficiency compare when running at the same compression ratio. ii) Comparing a modern diesel engine of compression ratio 16 with a modern petrol engine of compression ratio of 8. State and the reason why, which will have the highest thermal efficiency. 5 iii) Briefly describe; when these engines are running at part load how does their thermal efficiency change relative to stochiometric and why.