1. State five principal parts of an Internal Combustion Engine and their function: 1. Cylinder: Houses the piston and combustion process. 2. Piston: Moves up and down to convert pressure into mechanical work. 3. Connecting Rod: Connects piston to crankshaft, transmitting motion. 4. Crankshaft: Converts reciprocating motion of piston into rotary motion. 5. Cylinder Head: Seals the cylinder and contains valves for intake and exhaust. 2. Describe the two types of cylinder liners: 1. Dry Liner: Fits directly into the engine block, not in contact with coolant. 2. Wet Liner: Surrounded by coolant, improves heat dissipation. 3. List four parts of a piston and their functions: 1. Piston Head: Receives combustion pressure. 2. Piston Rings: Seal combustion chamber and control oil. 3. Piston Skirt: Guides piston in cylinder. 4. Piston Pin: Connects piston to connecting rod. 4. Design the piston head for a single acting four stroke engine: Given: Cylinder bore $d=100$ mm = 0.1 m Stroke $L=125$ mm = 0.125 m Maximum gas pressure $P_{max}=5$ N/mm$^2$ = $5\times10^6$ Pa Indicated mean effective pressure $P_{imep}=0.75$ N/mm$^2$ = $0.75\times10^6$ Pa Mechanical efficiency $\eta_m=0.8$ Fuel consumption $c=0.15$ kg/kW-hr Higher calorific value $H=42\times10^3$ kJ/kg = $42\times10^6$ J/kg Speed $N=2000$ rpm Step 1: Calculate indicated power $P_i$: $$P_i=\frac{P_{imep} \times V_s \times N}{2 \times 60}$$ where $V_s=\frac{\pi d^2}{4} \times L$ is swept volume. Calculate $V_s$: $$V_s=\frac{\pi (0.1)^2}{4} \times 0.125=9.82\times10^{-4} \text{ m}^3$$ Calculate $P_i$: $$P_i=\frac{0.75\times10^6 \times 9.82\times10^{-4} \times 2000}{2 \times 60}=12,275 \text{ W}$$ Step 2: Calculate brake power $P_b$: $$P_b=\eta_m \times P_i=0.8 \times 12,275=9,820 \text{ W}$$ Step 3: Calculate brake mean effective pressure $P_{bmeP}$: $$P_{bmeP}=\frac{P_b \times 2 \times 60}{V_s \times N}=\frac{9,820 \times 2 \times 60}{9.82\times10^{-4} \times 2000}=6.0 \times 10^5 \text{ Pa}$$ Step 4: Calculate piston head area $A$: $$A=\frac{\pi d^2}{4}=\frac{\pi (0.1)^2}{4}=7.85 \times 10^{-3} \text{ m}^2$$ Step 5: Calculate force on piston head $F$: $$F=P_{max} \times A=5\times10^6 \times 7.85 \times 10^{-3}=39,250 \text{ N}$$ Step 6: Design piston head thickness assuming allowable stress $\sigma=50$ MPa (assumed): $$t=\frac{F}{\sigma \times \pi d}=\frac{39,250}{50\times10^6 \times \pi \times 0.1}=2.5 \times 10^{-3} \text{ m} = 2.5 \text{ mm}$$ 5. Main parts of a torque converter and their functions: 1. Pump (Impeller): Connected to engine, pushes fluid. 2. Turbine: Connected to transmission, receives fluid energy. 3. Stator: Redirects fluid between pump and turbine to increase efficiency. 4. Housing: Contains all components and fluid. 6. Three stages of operation of a torque converter: 1. Stall: Turbine is stationary, maximum torque multiplication. 2. Acceleration: Turbine speed increases, torque multiplication decreases. 3. Coupling: Turbine speed approaches pump speed, torque ratio approaches 1. 7. Four possible failure modes of a torque converter: 1. Overheating due to fluid breakdown. 2. Bearing failure causing noise and vibration. 3. Seal leaks leading to fluid loss. 4. Stator clutch failure reducing torque multiplication.