(a) For the DI diesel engine for the friction force data in Fig. 13-20, estimate the maximum pressure force on the piston (under full-load conditions) and the approximate magnitude of the inertia...

(a) For the DI diesel engine for the friction force data in Fig. 13-20, estimate the maximum pressure force on the piston (under full-load conditions) and the approximate magnitude of the inertia force [mass of piston plus part of the connecting rod (7 kg) x $_p
x (N/4)]. Compare these forces with the piston friction force at time of peak pressure.

(b) Figure 13-6 shows the variation in friction force acting on the piston of a DI diesel engine under no-load and full-load firing conditions. Carefully sketch the shape (indicating direction and rough magnitude) of the cylinder pressure force on the piston, the piston velocity, and the piston acceleration, as functions of crank angle on the same graph as these friction forces. Use these graphs to explain.