Energy Engineering - Internal Combustion Engines

Full exam

19/01/22, 16:50 IC Engines - January 19, 2022. Part B (exercise) & C (theoretical questions) https://forms.office.com/Pages/ResponsePage.aspx?id=K3EXCvNtXUKAjjCd8ope64cHfHFJHqdBkPyq7vedZGJUQjMyRFU4NFpVNDRMNkpBTl … 1/3 IC Engines - January 19, 2022. Part B (exercise) & C (theoretical questions) 19/01/22, 16:50 IC Engines - January 19, 2022. Part B (exercise) & C (theoretical questions) https://forms.office.com/Pages/ResponsePage.aspx?id=K3EXCvNtXUKAjjCd8ope64cHfHFJHqdBkPyq7vedZGJUQjMyRFU4NFpVNDRMNkpBTl … 2/3 ICE_PolesAlessandro10534276_Alessandro Poles.pdf Part B, numerical exercise (5 points) We wish to design an outboard marine engine, SI, naturally aspirated, with a total displacement of 2800 cm3. 1- Evaluate the maximum power achievable at 6000 rpm, writing down the equations adopted (assume reasonable values for all the missing parameters). 2- Assuming four valves per cylinder, estimate the diameters and maximum lifts of intake and exhaust valves. 3- What is the pipe length to tune the ram effect at 3000 rpm and achieve a high torque? 4- Evaluate the Mach index (or gulp factor) at 6000 rpm and give your comments about the value achieved. --------------------------------------------------------------------------------------- ------------------- Part C, theoretical questions (16 points) 1) Describe both normal and abnormal combustion processes in a SI engine, pointing out the combustion phases, the flame front evolution and the main engine parameters involved. (6 points)   2) Discuss the main phases of the fuel injection process in a CI engine: surface instabilities and primary break-up, secondary break-up, role of cavitation; Sauter diameter, penetration and diffusion; range of injection pressures. (5 points) 3) Discuss the operation of an SCR catalyst, focusing on: working principle; injection of urea solution; different sections required in this after-treatment component; main chemical reactions; possible ammonia slip. (5 points) (Domanda non anonima ) (21 punti) 1.  19/01/22, 16:50 IC Engines - January 19, 2022. Part B (exercise) & C (theoretical questions) https://forms.office.com/Pages/ResponsePage.aspx?id=K3EXCvNtXUKAjjCd8ope64cHfHFJHqdBkPyq7vedZGJUQjMyRFU4NFpVNDRMNkpBTl … 3/3 Questo contenuto è creato dal proprietario del modulo. I dati inoltrati verranno inviati al proprietario del modulo. Microsoft non è responsabile per la privacy o le procedure di sicurezza dei propri clienti, incluse quelle del proprietario di questo modulo. Non fornire mai la password. Con tecnologia Microsoft Forms | Privacy e cookie | Condizioni per l'utilizzo